Table of Contents
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FEATURES
Dual 30A or Single 60A Digitally Adjustable Analog
n
Loops with Digital Interface for Control and Monitoring
Wide Input Voltage Range: 4.5V to 16V
n
Output Voltage Range: 0.5V to 3.3V
n
90% Full Load Efficiency from 12V
n
±0.5% Maximum DC Output Error Over Temperature
n
±2.5% Current Readback Accuracy (25°C to 125°C)
n
Integrated Input Current Sense Amplifier
n
400kHz PMBus-Compliant I
n
Supports Telemetry Polling Rates up to 125Hz
n
Constant Frequency Current Mode Control
n
Parallel and Current Share Multiple Modules
n
Pin Compatible with LTM4678
n
16mm × 16mm × 7.82mm BGA Package
n
Readable Data:
Input and Output Voltages, Currents, and Temperatures
n
Running Peak Values, Uptime, Faults and Warnings
n
Onboard EEPROM Fault Log Record
n
Writable Data and Configurable Parameters:
Output Voltage, Voltage Sequencing and Margining
n
Digital Soft-Start/Stop Ramp, Program Analog Loop
n
OV/UV/OT, UVLO, Frequency and Phasing
n
APPLICATIONS
System Optimization, Characterization and Data Mining
n
in Prototype, Production and Field Environments
TYPICAL APPLICATION
Dual 30A µModule Regulator with Digital Interface for Control and Monitoring*
4.5V to 16V
(FROM
4.5V TO 5.75V,
R
SENSE
CONNECT
22µF
V
, SV
×5
IN
IN
AND INTV
CC
TOGETHER)
ON/OFF CONTROL
FAULT INTERRUPTS
SYNCHRONIZATION TIME-BASE
REGISTER WRITE PROTECTION
*FOR COMPLETE CIRCUIT, SEE FIGURE 46
Document Feedback
Dual 30A or Single 60A µModule Regulator
with Digital Power System Management
to 1V
at 60A
IN
OUT
2
C Serial Interface
+
V
IN
OUT0
+
V
OSNS0
LOAD0
–
IN
–
V
OSNS0
V
IN1
V
IN0
V
OUT1
SV
IN
+
V
OSNS1
RUN1
LTM4680
LOAD1
RUN0
–
V
OSNS1
FAULT0
FAULT1
2
I
C/SMBus I/F WITH PMBus
SCL
SYNC
COMMAND SET TO/FROM
SDA
IPMI OR OTHER BOARD
SHARE_ CLK
ALERT
MANAGEMENT CONTROLLER
WP
SGND
GND
4680 TA01a
For more information
DESCRIPTION
The
LTM
4680
is a dual 30A or single 60A step-down
®
µModule
(power module) DC/DC regulator featuring
®
remote configurability and telemetry-monitoring of power
management parameters over
2
dard I
C-based digital interface protocol. The LTM4680
is comprised of digitally programmable analog control
loops, precision mixed-signal circuitry, EEPROM, power
MOSFETs, inductors and supporting components.
The LTM4680 product video is available on the website.
The LTM4680's 2-wire serial interface allows outputs
to be margined, tuned and ramped up and down at pro-
grammable slew rates with sequencing delay times. True
input current sense, output currents and voltages, output
power, temperatures, uptime and peak values are read-
able. Custom configuration of the EEPROM contents is not
required. At start-up, output voltages, switching frequency,
and channel phase angle assignments can be set by pin-
strapping resistors. The
USB-to-PMBus converter and demo kits are available.
The LTM4680 is offered in a 16mm × 16mm × 7.82mm
BGA package available with SnPb or RoHS compliant ter-
minal finish. Pin compatible with LTM4678.
All registered trademarks and trademarks are the property of their respective owners. Protected
by U.S. Patents including 5408150, 5481178, 5705919, 5929620, 6144194, 6177787, 6580258,
7420359, 8163643. Licensed under U.S. Patent 7000125 and other related patents worldwide.
Click to view associated Video Design Idea.
100
V
OUT0
ADJUSTABLE
UP TO 30A
100µF
×8
V
OUT1
ADJUSTABLE
UP TO 30A
100µF
×8
www.analog.com
LTM4680
PMBus—an open stan-
LTpowerPlay
GUI and DC1613
®
Efficiency vs Current at 12V Input
95
90
85
80
75
70
1.0V, 250kHz
1.5V, 425kHz
65
0
5
10
15
20
25
LOAD CURRENT (A)
30
4680 TA01b
Rev. B
1
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Table of Contents
Related Manuals for Linear ANALOG DEVICES LTM4680
Summary of Contents for Linear ANALOG DEVICES LTM4680
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Page 1: Features
LTM4680 Dual 30A or Single 60A µModule Regulator with Digital Power System Management FEATURES DESCRIPTION Dual 30A or Single 60A Digitally Adjustable Analog 4680 is a dual 30A or single 60A step-down ® Loops with Digital Interface for Control and Monitoring µModule (power module) DC/DC regulator featuring ®... -
Page 2: Table Of Contents
LTM4680 TABLE OF CONTENTS Features ............. 1 Table 3. FSWPH_CFG Pin Strapping Look-Up Table Applications ..........1 to Set the LTM4680’s Switching Frequency and Typical Application ........1 Channel Phase-Interleaving Angle (Not Applicable Description..........1 if MFR_CONFIG_ALL[6] = 1b) ......32 Table of Contents .......... - Page 3 LTM4680 TABLE OF CONTENTS PMBus Command Summary ......45 Derating Curves ............69 PMBus Commands ..........45 EMI Performance ........... 70 Table 7. PMBus Commands Summary (Note: Safety Considerations ..........70 The Data Format Abbreviations Are Detailed in Layout Checklist/Example ........70 Table 8) ............45 Typical Applications ........
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Page 4: Absolute Maximum Ratings
LTM4680 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW Terminal Voltages: – OSNS1 OSNS1 − (Note 4), SV ...... –0.3V to 18V − – I ), (I – I ) ......–0.3V to 0.3V OUT1 SW0, SW1 ....−1V to 18V, −5V to 18V Transient TRIM0_ OUT1 COMP1b... -
Page 5: Electrical Characteristics
LTM4680 ELECTRICAL CHARACTERISTICS denotes the specifications which apply over the specified internal operating temperature range (Note 2). n is specified as each individual output channel (Note 4). T = 25°C, V = 12V, RUNn = 3.3V, EXTV = 0, FREQUENCY_SWITCH = 350kHz and V commanded to 1.000V unless otherwise noted. - Page 6 LTM4680 ELECTRICAL CHARACTERISTICS denotes the specifications which apply over the specified internal operating temperature range (Note 2). n is specified as each individual output channel (Note 4). T = 25°C, V = 12V, RUNn = 3.3V, EXTV = 0, FREQUENCY_SWITCH = 350kHz and V commanded to 1.000V unless otherwise noted.
- Page 7 LTM4680 ELECTRICAL CHARACTERISTICS denotes the specifications which apply over the specified internal operating temperature range (Note 2). n is specified as each individual output channel (Note 4). T = 25°C, V = 12V, RUNn = 3.3V, EXTV = 0, FREQUENCY_SWITCH = 350kHz and V commanded to 1.000V unless otherwise noted.
- Page 8 LTM4680 ELECTRICAL CHARACTERISTICS denotes the specifications which apply over the specified internal operating temperature range (Note 2). n is specified as each individual output channel (Note 4). T = 25°C, V = 12V, RUNn = 3.3V, EXTV = 0, FREQUENCY_SWITCH = 350kHz and V commanded to 1.000V unless otherwise noted.
- Page 9 LTM4680 ELECTRICAL CHARACTERISTICS denotes the specifications which apply over the specified internal operating temperature range (Note 2). n is specified as each individual output channel (Note 4). T = 25°C, V = 12V, RUNn = 3.3V, EXTV = 0, FREQUENCY_SWITCH = 350kHz and V commanded to 1.000V unless otherwise noted.
- Page 10 LTM4680 ELECTRICAL CHARACTERISTICS denotes the specifications which apply over the specified internal operating temperature range (Note 2). n is specified as each individual output channel (Note 4). T = 25°C, V = 12V, RUNn = 3.3V, EXTV = 0, FREQUENCY_SWITCH = 350kHz and V commanded to 1.000V unless otherwise noted.
- Page 11 Note 10: The following telemetry parameters are formatted in PMBus- defined “Linear Data Format”, in which each register contains a word comprised of 5 most significant bits—representing a signed exponent, to be raised to the power of 2—and 11 least significant bits—representing...
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Page 12: Typical Performance Characteristics
LTM4680 TYPICAL PERFORMANCE CHARACTERISTICS = 25°C. Single Channel Efficiency, Single Channel Efficiency, = SV = EXTV = 5V = SV = 8V, CCM Mode EXTV = 5V, CCM Mode 0.9V, 250kHz 0.9V, 250kHz 1.0V, 250kHz 1.0V, 250kHz 1.2V, 350kHz 1.2V, 350kHz 1.5V, 425kHz 1.5V, 425kHz 1.8V, 500kHz... - Page 13 LTM4680 TYPICAL PERFORMANCE CHARACTERISTICS = 25°C, unless otherwise noted. Single Channel Load Transient Single Channel Load Transient Single Channel Load Transient Response 50% (15A) to 100% (30A) Response 50% (15A) to 100% (30A) Response 50% (15A) to 100% (30A) Load Step, 15A/µs V = 12V, Load Step, 15A/µs V = 12V,...
- Page 14 LTM4680 TYPICAL PERFORMANCE CHARACTERISTICS = 25°C, 12V to 1V , unless otherwise noted. Supply Current vs Load Current Supply Current vs Load Current Supply Current vs Load Current Comparison, R = 3mΩ, Comparison, R = 3mΩ, Comparison, R = 3mΩ, SENSE SENSE SENSE...
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Page 15: Pin Functions
LTM4680 PIN FUNCTIONS SGND (F9-10, G9-10): SGND is the signal ground return PACKAGE ROW AND COLUMN LABELING MAY VARY AMONG µModule PRODUCTS. REVIEW EACH PACKAGE path of the LTM4680. SGND is not internally connected to LAYOUT CAREFULLY . GND. Connect SGND to GND local to the LTM4680. See GND (A3-A6, B1, B3-B6, C1-C6, D2-D6, E5-E6, F5-F7, recommended layout. - Page 16 LTM4680 PIN FUNCTIONS and MFR_ADC_CONTROL COMMAND section. When (D12): Internally Generated 2.5V Power Supply DD25 operating from 4.5V to 5.75V with no auxiliary bias sup- Output Pin. Do not load this pin with external current; ply, then the main input supply should connect to SV it is used strictly to bias internal logic and provides cur- and INTV .
- Page 17 LTM4680 PIN FUNCTIONS MFR_CONFIG_ALL[6] = 1b then the LTM4680’s target VOUT0_CFG (E11): Output Voltage Select Pin for V OUT0 output voltage setting (VOUT_COMMAND1) and Coarse Setting. If the VOUT0_CFG and VTRIM0_CFG pins OUT1 associated OV/UV warning and fault thresholds are dic- are both left open—or, if the LTM4680 is configured to tated at SV power-up according to the LTM4680’s NVM ignore pin-strap (RCONFIG) resistors, i.e., MFR_CONFIG_...
- Page 18 LTM4680 PIN FUNCTIONS FAULT0/FAULT1 (H12/G11): Digital Programmable Fault solid serial bus communications, and only then should Inputs and Outputs. Open-drain output. A pull-up resistor MFR_CONFIG_ALL[1] be set to 1b. When clock stretch- to 3.3V is required in the application. ing is enabled, SCL becomes a bidirectional, open-drain output pin on LTM4680.
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Page 19: Simplified Block Diagram
LTM4680 SIMPLIFIED BLOCK DIAGRAM SENSE 2.2µF – INTV EXTV DD33 1Ω 1µF 2.2µF 2.2µF 1µF 1µF A = N INPUT CURRENT/ICHIP (READ_IIN, MFR_READ_IIN_PEAK TO ANALOG READBACK) OUT0 OUT1 TO 3.3V TO 3.3V UP TO 30A 330nH 330nH UP TO 30A OUT0 OUT1 POWER CONTROL... -
Page 20: Functional Diagram
LTM4680 FUNCTIONAL DIAGRAM – Figure 3. Functional LTM4680 Block Diagram Rev. B For more information www.analog.com... -
Page 21: Test Circuits
LTM4680 TEST CIRCUITS Test Circuit 1. LTM4680 ATE High V Operating Range Configuration, 5.75V ≤ V ≤ 16V 2.2µF 5.75V TO 16V 150µF OUT0 SENSE OUT0 1V, ADJUSTABLE – OSNS0 UP TO 3.6V AT 30A 100µF LOAD0 22µF ×4 – ×5 * BULK OSNS0... - Page 22 LTM4680 TEST CIRCUITS Test Circuit 2. LTM4680 ATE Low V Operating Range Configuration, 4.5V ≤ V ≤ 5.75V 2.2µF 4.5V TO 5.75V 150µF OUT0 SENSE OUT0 1V, ADJUSTABLE – OSNS0 UP TO 3.6V AT 30A 100µF LOAD0 22µF ×4 – ×5 * BULK OSNS0...
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Page 23: Operation
LTM4680 OPERATION POWER MODULE INTRODUCTION Programmable Output Voltage The LTM4680 is a highly configurable dual 30A out- Programmable Input Voltage On and Off Threshold put standalone nonisolated switching mode step-down Voltage DC/DC power supply with built-in EEPROM NVM (non- Programmable Current Limit volatile memory) with ECC and I C-based PMBus/ SMBus Programmable Switching Frequency... -
Page 24: Eeprom With Ecc
LTM4680 OPERATION Three dedicated pins for ALERT, PGOOD0/PGOOD1 func- The degradation in EEPROM retention for temperatures tions are provided. The shutdown operation also allows >125°C can be approximated by calculating the dimen- all faults to be individually masked and can be operated sionless acceleration factor using the following equation: in either unlatched (hiccup) or latched modes. -
Page 25: Power-Up And Initialization
4V and the 5.5V, 3.3V and 2.5V pin programming; see Table 3. Configure the LTM4680’s linear regulators must be within approximately 20% of NVM to implement settings not available by resistor- the regulated values. In addition to the power supply, a pin strapping.) When a FSWPH_CFG pin-strap resistor... -
Page 26: Soft-Start
LTM4680 OPERATION will use only the contents of NVM to determine the DC/ (TON_DELAY) prior to initiating this output voltage ramp. DC characteristics. The ASEL value read at power-up or The rise time of the voltage ramp can be programmed reset is always respected unless the pin is open. -
Page 27: Shutdown
LTM4680 OPERATION threshold is exceeded for each output. It is possible to There are two ways to respond to faults; which are retry feed the PGOOD pin from one LTM4680 into the RUN pin mode and latched off mode. In retry mode, the con- of the next LTM4680 in the sequence, especially across troller responds to a fault by shutting down and enter- multiple LTM4680s. -
Page 28: Switching Frequency And Phase
When the EXTV pin is shorted to GND or figure the phase of each channel. Desired phase can also tied to a voltage less than 4.7V, an internal 5.5V linear be set from EEPROM or external configuration resistors regulator supplies INTV power from V . -
Page 29: Output Current Sensing And Sub Milliohm Dcr Current Sensing
±128mV, a noise floor of 7µV , and a peak-peak noise of power to the internal 3.3V linear regulator even when V approximately 46.5µV. The LTM4680 computes the induc- is not present, which allows the LTM4680 to be initialized tor current using the DCR value stored in the IOUT_CAL_ and programmed even without main power being applied. -
Page 30: External/Internal Temperature Sense
LTM4680 OPERATION Multiple channels need to tie all the V pins together, the output voltage. The default setting is to have the OSNSn and all the V – pins together, C and C switcher off unless the voltage configuration pins are OSNSn OMPna OMPnb... -
Page 31: Applicable If Mfr_Config_All[6] = 1B)
LTM4680 OPERATION NOTE: Per the PMBus specification, pin programmed parameters can be overridden by commands from the Table 2. VTRIMn_CFG Pin Strapping Look-Up Table for the digital interface with the exception of ASEL which is LTM4680’s Output Voltage, Fine Adjustment Setting (Not always honored. -
Page 32: If Mfr_Config_All[6] = 1B)
LTM4680 OPERATION Table 3. FSWPH_CFG Pin Strapping Look-Up Table to Set the LTM4680’s Switching Frequency and Channel Phase-Interleaving Angle (Not Applicable if MFR_CONFIG_ALL[6] = 1b) SWITCHING bits [2:0] of bit [4] of FSWPH_CFG (kΩ) FREQUENCY (kHz) θSYNC TO θ0 θSYNC TO θ1 MFR_PWM_CONFIG MFR_CONFIG_ALL NVM;... -
Page 33: Fault Detection And Handling
LTM4680 OPERATION Table 4. ASEL Pin Strapping Look-Up Table to Set the Table 5. LTM4680 MFR_ADDRESS Command Examples LTM4680’s Slave Address (Applicable Regardless of Expressed in 7- and 8-Bit Addressing MFR_CONFIG_ALL[6] Setting) HEX DEVICE ADDRESS * (kΩ) SLAVE ADDRESS ASEL DESCRIPTION 7-BIT 8-BIT 7 6 5 4 3 2 1 0 R/W Open... -
Page 34: Status Registers And Alert Masking
LTM4680 OPERATION overvoltage alert or as an interrupt to cause a micro- In general, any asserted bit in a STATUS_x register also controller to poll the fault commands. Alternatively, the pulls the ALERT pin low. Once set, ALERT will remain low FAULTn pins can be used as inputs to detect external faults until one of the following occurs. - Page 35 LTM4680 OPERATION STATUS_WORD STATUS_VOUT* VOUT IOUT VOUT_OV Fault INPUT STATUS_INPUT VOUT_OV Warning MFR_SPECIFIC VOUT_UV Warning VIN_OV Fault POWER_GOOD# VOUT_UV Fault (reads 0) (reads 0) VOUT_MAX Warning VIN_UV Warning (reads 0) TON_MAX Fault (reads 0) (reads 0) TOFF_MAX Warning Unit Off for Insuffcient VIN (reads 0) STATUS_BYTE (reads 0)
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Page 36: Mapping Faults To Fault Pins
LTM4680 OPERATION Mapping Faults to FAULT Pins repair can be attempted by writing the desired configura- tion to the controller and executing a STORE_USER_ALL Channel-to-channel fault (including channels from mul- command followed by a CLEAR_FAULTS command. tiple LTM4680s) dependencies can be created by con- necting FAULTn pins together. -
Page 37: Responses To V
LTM4680 OPERATION Global addressing provides a means of the PMBus master The I and I overcurrent monitors are performed by to address all LTM4680 devices on the bus. The LTM4680 ADC readings and calculations. Thus these values are global address is fixed 0x5A (7-bit) or 0xB4 (8-bit) and based on average currents and can have a time latency cannot be disabled. -
Page 38: Output Undervoltage Response
LTM4680 OPERATION Output Undervoltage Response FAULT_LIMIT is 10µs. If the VOUT_UV_FAULT _LIMIT is not reached within the TON_MAX_FAULT_LIMIT time, The response to an undervoltage comparator output can the response of this fault is determined by the value of be the following: the TON_MAX_FAULT_RESPONSE command value. -
Page 39: External Overtemperature And Undertemperature Fault Response
LTM4680 OPERATION External Overtemperature and Undertemperature FAULT LOGGING Fault Response The LTM4680 has fault logging capability. Data is logged Two internal temperature sensors are used to sense the into memory in the order shown in Table 19. The data is temperature of critical circuit elements like inductors stored in a continuously updated buffer in RAM. -
Page 40: Similarity Between Pmbus, Smbus And I 2 C 2-Wire Interface
LTM4680 OPERATION applies primarily to the MFR_FAULT_LOG command. The PMBus SERIAL DIGITAL INTERFACE timeout period defaults to 32ms. The LTM4680 communicates with a host (master) using The user is encouraged to use as high a clock rate as the standard PMBus serial bus interface. The Timing possible to maintain efficient data packet transfer between Diagram, Figure 6, shows the timing relationship of the all devices sharing the serial bus interface. - Page 41 Table 6. Abbreviations of Supported Data Formats PMBus SPECIFICATION TERMINOLOGY REFERENCE TERMINOLOGY DEFINITION EXAMPLE Linear Part II ¶7.1 Linear_5s_1s Floating point 16-bit data: value = Y • 2 b[15:0] = 0x9807 = 10011_000_0000_0111 –13 where N = b[15:11] and Y = b[10:0], both value = 7 •...
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Page 42: Figures 7 To 24 Pmbus Protocols
LTM4680 OPERATION FIGURES 7 TO 24 PMBus PROTOCOLS START CONDITION REPEATED START CONDITION READ (BIT VALUE OF 1) WRITE (BIT VALUE OF 0) ACKNOWLEDGE (THIS BIT POSITION MAY BE 0 FOR AN ACK OR 1 FOR A NACK) STOP CONDITION PEC PACKET ERROR CODE MASTER TO SLAVE SLAVE TO MASTER... - Page 43 LTM4680 OPERATION SLAVE ADDRESS Wr A COMMAND CODE A Sr SLAVE ADDRESS DATA BYTE 4680 F15 Figure 15. Read Byte Protocol SLAVE ADDRESS Wr A COMMAND CODE A Sr SLAVE ADDRESS DATA BYTE 4680 F16 Figure 16. Read Byte Protocol with PEC SLAVE ADDRESS Wr A COMMAND CODE...
- Page 44 LTM4680 OPERATION SLAVE ADDRESS Wr A COMMAND CODE BYTE COUNT = M DATA BYTE 1 … DATA BYTE 2 … DATA BYTE M … SLAVE ADDRESS Rd A BYTE COUNT = N DATA BYTE 1 … … DATA BYTE 2 …...
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Page 45: Pmbus Command Summary
Table 7. Floating point values listed in new commands. In these circumstances the part follows the “DEFAULT VALUE” column are either Linear 16-bit the protocols defined in the PMBus Specification v1.2, Signed (PMBus Section 8.3.1) or Linear_5s_11s (PMBus Part II, Section 10.8.7, to communicate that it is busy. - Page 46 LTM4680 PMBus COMMAND SUMMARY DATA DEFAULT COMMAND NAME CODE DESCRIPTION TYPE PAGED FORMAT UNITS NVM VALUE PAGE VOUT_MARGIN_HIGH 0x25 Margin high output voltage set point. Must R/W Word 1.05 be greater than VOUT_COMMAND. 0x10CD VOUT_MARGIN_LOW 0x26 Margin low output voltage set point. Must R/W Word 0.95 be less than VOUT_COMMAND.
- Page 47 LTM4680 PMBus COMMAND SUMMARY DATA DEFAULT COMMAND NAME CODE DESCRIPTION TYPE PAGED FORMAT UNITS NVM VALUE PAGE TON_DELAY 0x60 Time from RUN and/or Operation on to R/W Word output rail turn-on. 0x8000 TON_RISE 0x61 Time from when the output starts to rise R/W Word until the output voltage reaches the V 0xC300...
- Page 48 LTM4680 PMBus COMMAND SUMMARY DATA DEFAULT COMMAND NAME CODE DESCRIPTION TYPE PAGED FORMAT UNITS NVM VALUE PAGE MFR_VOUT_MAX 0xA5 Maximum allowed output voltage R Word including VOUT_OV_FAULT_LIMIT. 0x399A MFR_PIN_ACCURACY 0xAC Returns the accuracy of the READ_PIN R Byte 5.0% command USER_DATA_00 0xB0 OEM RESERVED.
- Page 49 LTM4680 PMBus COMMAND SUMMARY DATA DEFAULT COMMAND NAME CODE DESCRIPTION TYPE PAGED FORMAT UNITS NVM VALUE PAGE MFR_ADDRESS 0xE6 Sets the 7-bit I C address byte. R/W Byte 0x4F MFR_SPECIAL_ID 0xE7 Manufacturer code representing the R Word 0x414X LTM4680 and revision MFR_IIN_CAL_GAIN 0xE8 The resistance value of the input current...
- Page 50 LTM4680 PMBus COMMAND SUMMARY Table 8. Data Format Abbreviations Linear_5s_11s PMBus data field b[15:0] Value = Y • 2 where N = b[15:11] is a 5-bit two’s complement integer and Y = b[10:0] is an 11-bit two’s complement integer Example: For b[15:0] = 0x9807 = ‘b10011_000_0000_0111 –13 –6 Value = 7 •...
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Page 51: Applications Information
LTM4680 APPLICATIONS INFORMATION TO V STEP-DOWN RATIOS OUTPUT CAPACITORS There are restrictions in the maximum V and V step- The LTM4680 is designed for low output voltage ripple down ratio that can be achieved for a given input voltage. noise and good transient response. The bulk output Each output of the LTM4680 is capable of 95% duty cycle capacitors defined as C are chosen with low enough... -
Page 52: Switching Frequency And Phase
LTM4680 APPLICATIONS INFORMATION reverse current comparator, I , turns off the bottom ALL[4] = 1b. This can be easily implemented with resistor MOSFET (MBn) just before the inductor current reaches pin-strap settings on the FSWPH_CFG pin (see Table 3). zero, preventing it from reversing and going negative. Using MFR_CONFIG_ALL[4] = 1b, the LTM4680s SYNC Thus, the controller can operate in discontinuous (pulse- pin becomes a high impedance input, only—i.e., it does... -
Page 53: Output Current Limit Programming
LTM4680 APPLICATIONS INFORMATION phasing with respect to the SYNC pin. Phase relationship Table 9. Recommended Switching Frequency for Various V values are indicated with 0° corresponding to the falling to-V Step-Down Scenarios edge of SYNC being coincident with the turn-on of the top MOSFETs. -
Page 54: Minimum On-Time Considerations
LTM4680 APPLICATIONS INFORMATION MINIMUM ON-TIME CONSIDERATIONS in frequency, thus the actual time delays will have some variance. Minimum on-time, t , is the smallest time dura- ON(MIN) tion that the LTM4680 is capable of turning on the top Soft-start is performed by actively regulating the load MOSFET. -
Page 55: Soft Off (Sequenced Off)
LTM4680 APPLICATIONS INFORMATION This same point in time is when the output changes from SOFT OFF (SEQUENCED OFF) discontinuous to the programmed mode as indicated in In addition to a controlled start-up, the LTM4680 also MFR_PWM_MODE bit 0. Refer to Figure 25 for details on supports controlled turn-off. -
Page 56: Undervoltage Lockout
LTM4680 APPLICATIONS INFORMATION UNDERVOLTAGE LOCKOUT can be pulled low by external sources indicating a fault in some other portion of the system. The fault response is The LTM4680 is initialized by an internal threshold-based configurable and allows the following options: UVLO where VIN must be approximately 4V and INTVCC, VDD33, and VDD25 must be within approximately 20% of Ignore... -
Page 57: Phase-Locked Loop And Frequency Synchronization
LTM4680 APPLICATIONS INFORMATION All the above pins have on-chip pull-down transistors that PHASE-LOCKED LOOP AND FREQUENCY can sink 3mA at 0.4V. The low threshold on the pins is SYNCHRONIZATION 0.8V; thus, there is plenty of margin on the digital signals The LTM4680 has a phase-locked loop (PLL) comprised with 3mA of current. -
Page 58: Input Current Sense Amplifier
LTM4680 APPLICATIONS INFORMATION to avoid this problem. Multiple LTM4680s are required change. The error amplifier gain g varies from 1.0mmho to share one SYNC pin in PolyPhase configurations. to 5.73mmho, and the compensation resistor R COMPn For other configurations, connecting the SYNC pins to varies from 0kΩ... -
Page 59: Checking Transient Response
LTM4680 APPLICATIONS INFORMATION The COMPna series internal R and external C TYPE II COMPENSATION COMPn COMPna filter sets the dominant pole-zero loop compensation. GAIN The internal R value can be modified (from 0Ω to COMPn 62kΩ) using bits[4:0] of the MFR_PWM_ COMP com- mand. -
Page 60: Polyphase Configuration
LTM4680 APPLICATIONS INFORMATION is greater than 1:50, the switch rise time should be CONNECTING THE USB TO I C/SMBUS/PMBUS controlled so that the load rise time is limited to approxi- CONTROLLER TO THE LTM4680 IN SYSTEM mately 25 • C . -
Page 61: Ltpowerplay: An Interactive Gui For Digital Power
LTM4680 APPLICATIONS INFORMATION Because of the adapter’s limited current sourcing capabil- automatic update feature to keep the revisions current ity, only the LTM4680s, their associated pull-up resistors with the latest set of device drivers and documentation. and the I C pull-up resistors should be powered from A great deal of context sensitive help is available with the V 3.3V supply. - Page 62 LTM4680 APPLICATIONS INFORMATION Figure 31. LTpowerPlay Screen Shot WRITE COMMAND DATA BUFFER PMBus DECODER INTERNAL WRITE PAGE 0x00 PROCESSOR • CMDS FETCH, • • CONVERT 0x21 DATA DATA VOUT_COMMAND • EXECUTE • • 0xFD MFR_RESET CALCULATIONS PENDING 4680 F32 Figure 32. Write Command Data Processing Rev.
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Page 63: Thermal Considerations And Output Current Derating
LTM4680 APPLICATIONS INFORMATION or stretch the SCL clock low. For more information refer is to create a SAFE_WRITE_BYTE() and SAFE_WRITE_ to PMBus Specification v1.1, Part II, Section 10.8.7 WORD() subroutine. The above polling mechanism allows and SMBus v2.0 section 4.3.3. Clock stretching can be your software to remain clean and simple while robustly enabled by asserting bit 1 of MFR_CONFIG_ ALL. - Page 64 LTM4680 APPLICATIONS INFORMATION can be used in a manner that yields insight and guidance typical µModule regulator are on the bottom of the pertaining to one’s application-usage, and can be adapted package, it is rare for an application to operate such to correlate thermal performance to one’s own application.
- Page 65 0.9V and 1.8V. These are chosen to include ent junctions of components or die are not exactly linear the lower and higher output voltage ranges for correlating with respect to total package power loss. To reconcile this the thermal resistance.
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Page 66: Tables 10 Thru 11: Output Current Derating
LTM4680 APPLICATIONS INFORMATION Tables 10 thru 11: Output Current Derating Table 10. 0.9V Output DERATING CURVE POWER LOSS CURVE AIRFLOW (LFM) HEAT SINK (°C/W) θ Figure 38 to Figure 40 5, 8, 12 Figure 35 to Figure 37 None Figure 38 to Figure 40 5, 8, 12 Figure 35 to Figure 37 None Figure 38 to Figure 40... - Page 67 LTM4680 APPLICATIONS INFORMATION Table 13. Channel Output Voltage vs Capacitor Selection, Bulk and Ceramic Cap Configuration, 15A to 30A Load Step with 15A/µs Slew Rate PK-PK RECOVERY ILIM RCOMP EA-GM LOAD STEP DEVIATION TIME COMP COMP RANGE RANGE (CER CAP) (BULK CAP) (pF) (nF) (kΩ)
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Page 68: Slew Rate
LTM4680 APPLICATIONS INFORMATION Table 14. Dual Phase Single Output Voltage vs Capacitor Selection, Bulk and Ceramic Cap Configuration, 30A to 60A Load Step with 30A/µs Slew Rate PK-PK RECOVERY ILIM RCOMP EA-GM LOAD STEP DEVIATION TIME COMP COMP RANGE RANGE (CER CAP) (BULK CAP) (pF) (nF) -
Page 69: Derating Curves
LTM4680 APPLICATIONS INFORMATION-DERATING CURVES DERATING CURVES 0.9V, 250kHz 0.9V, 250kHz 0.9V, 250kHz 1.0V, 250kHz 1.0V, 250kHz 1.0V, 250kHz 1.2V, 350kHz 1.2V, 350kHz 1.2V, 350kHz 1.5V, 425kHz 1.5V, 425kHz 1.5V, 425kHz 1.8V, 500kHz 1.8V, 500kHz 1.8V, 500kHz 2.5V, 575kHz 2.5V, 575kHz 2.5V, 575kHz 3.3V, 650kHz 3.3V, 650kHz... -
Page 70: Emi Performance
LTM4680 APPLICATIONS INFORMATION SAFETY CONSIDERATIONS EMI PERFORMANCE The SWn pin provides access to the midpoint of the power The LTM4680 modules do not provide galvanic isolation from V to V . There is no internal fuse. If required, MOSFETs in LTM4680’s power stages. a slow blow fuse with a rating twice the maximum input Connecting an optional series RC network from SWn to current needs to be provided to protect each unit from... - Page 71 LTM4680 APPLICATIONS INFORMATION – Do not put vias directly on pads, unless they are For parallel modules, tie the V , ,V OUTn OSNSn OSNSn capped or plated over. voltage-sense differential pair lines, RUNn, , COMPna, COMPnb pin together. The user must share the SYNC, Use a separate SGND copper plane for components SHARE_CLK, FAULT, and ALERT pins of these parts.
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Page 72: Typical Applications
LTM4680 TYPICAL APPLICATIONS DD33 2.2µF PGOOD DD33 5.75V TO 16V OUT0 150µF 1mΩ 100µF 470µF – ×5 ×2 22µF 0.9V AT 60A ×5 OSNS0 – OSNS0 DD33 OUT1 4.99k 100µF 470µF LTM4680 ×5 ×2 RUN1 – OSNS0 OSNS1 ON/OFFCONFIG – OSNS1 RUN0 LOAD... - Page 73 LTM4680 TYPICAL APPLICATIONS DD33 2.2µF PGOOD0 PGOOD1 DD33 RSNUB0 5.75V TO 16V CSNUB0 150µF 1mΩ – OUT0 1V, 30A OUT0 OSNS0 22µF 100µF 470µF LOAD0 ×5 ×4 ×3 – OSNS0 RSNUB1 DD33 CSNUB1 4.99k OUT1 1.5V, 30A OUT1 LTM4680 OSNS1 RUN1 100µF 470µF...
- Page 74 LTM4680 TYPICAL APPLICATIONS 4.99k DD33 PGOOD BIAS 2.2µF 5.75V TO 16V 150µF OUT0 100µF 470µF – ×4 OSNS0 ×2 – OSNS0 22µF ×4 DD33 OUT1 4.99k 100µF 470µF LTM4680 OSNS1 ×4 RUN1 ×2 – ON/OFF CONTROL OSNS1 RUN0 FAULT INTERRUPTS FAULT0 FAULT1 ALERT...
- Page 75 LTM4680 TYPICAL APPLICATIONS BIAS DD33 2.2µF PGOOD0 DD33 3.3V 22µF 220µF ×5 OUT0 100µF ×3 74HC1G09 1V AT 30A OSNS0 – LOAD 330µF 5V BIAS – OSNS0 DD33 5V BIAS ≥50mA OUT1 100µF 4.99k ×3 LTM4680 RUN1 1.2V AT 30A OSNS1 ON/OFFCONFIG LOAD...
- Page 76 LTM4680 TYPICAL APPLICATIONS 4.99k DD33 BIAS BIAS ≥200mA 2.2µF 2.2µF PGOOD PGOOD DD33 5.75V TO 16V OUT0 22µF OUT0 150µF 22µF ×4 470µF – – 100µF OSNS0 ×4 OSNS0 ×4 ×8 – – OSNS0 OSNS0 DD33 OUT1 OUT1 4.99k 100µF 470µF OSNS1 LTM4680...
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Page 77: Pmbus Command Details
LTM4680 PMBus COMMAND DETAILS ADDRESSING AND WRITE PROTECT DATA DEFAULT COMMAND NAME CODE DESCRIPTION TYPE PAGED FORMAT UNITS NVM VALUE PAGE 0x00 Provides integration with multi-page PMBus devices. R/W Byte 0x00 PAGE_PLUS_WRITE 0x05 Write a supported command directly to a PWM channel. W Block PAGE_PLUS_READ 0x06 Read a supported command directly from a PWM Block... - Page 78 LTM4680 PMBus COMMAND DETAILS The value stored in the PAGE command is not affected by PAGE_PLUS_READ. If PAGE_PLUS_READ is used to access data from a non-paged command, the Page Number byte is ignored. This command uses the Process Call protocol. An example of the PAGE_PLUS_READ command with PEC is shown in Figure 51.
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Page 79: General Configuration Commands
LTM4680 PMBus COMMAND DETAILS MFR_ADDRESS The MFR_ADDRESS command byte sets the 7 bits of the PMBus slave address for this device. Setting this command to a value of 0x80 disables device addressing. The GLOBAL device address, 0x5A and 0x5B, cannot be deactivated. If RCONFIG is set to ignore, the ASEL pin is still used to determine the LSB of the channel address. -
Page 80: On/Off/Margin
LTM4680 PMBus COMMAND DETAILS A ShortCycle event occurs whenever the PWM channel is commanded back ON, or reactivated, after the part has been commanded OFF and is processing either the TOFF_DELAY or the TOFF_FALL states. The PWM channel can be turned ON and OFF through either the RUN pin and or the PMBus OPERATION command. - Page 81 LTM4680 PMBus COMMAND DETAILS ON_OFF_CONFIG The ON_OFF_CONFIG command specifies the combination of RUNn pin input state and PMBus commands needed to turn the PWM channel on and off. Supported Values: VALUE MEANING 0x1F OPERATION value and RUNn pin must both command the device to start/run. Device executes immediate off when commanded off. 0x1E OPERATION value and RUNn pin must both command the device to start/run.
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Page 82: Pwm Configuration
LTM4680 PMBus COMMAND DETAILS PWM CONFIGURATION DATA DEFAULT COMMAND NAME CMD CODE DESCRIPTION TYPE PAGED FORMAT UNITS NVM VALUE MFR_PWM_COMP 0xD3 PWM loop compensation configuration R/W Byte 0x28 MFR_PWM_MODE 0xD4 Configuration for the PWM engine. R/W Byte 0x47 MFR_PWM_CONFIG 0xF5 Set numerous parameters for the DC/DC controller R/W Byte 0x10... - Page 83 LTM4680 PMBus COMMAND DETAILS For both equations, –14 G = MFR_TEMP_1_GAIN • 2 , and O = MFR_TEMP_1_OFFSET Bit[2] is now reserved, and Ultra Low DCR mode is default. Bit[1] of this command determines if the part is in high range or low voltage range. Changing this bit value changes the PWM loop gain and compensation.
- Page 84 LTM4680 PMBus COMMAND DETAILS MEANING 10000b 10001b 10010b 10011b 10100b 10101b 10110b 10111b 11000b 11001b 11010b 11011b 11100b 11101b 11110b 11111b This command has one data byte. MFR_PWM_CONFIG The MFR_PWM_CONFIG command sets the switching frequency phase offset with respect to the falling edge of the SYNC signal.
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Page 85: Voltage
LTM4680 PMBus COMMAND DETAILS FREQUENCY_SWITCH The FREQUENCY_SWITCH command sets the switching frequency, in kHz, of the LTM4680. Supported Frequencies: VALUE [15:0] RESULTING FREQUENCY (TYP) 0x0000 External Oscillator 0xF3E8 250kHz 0xFABC 350kHz 0xFB52 425kHz 0xFBE8 500kHz 0x023F 575kHz 0x028A 650kHz 0x02EE 750kHz 0x03E8 1000kHz... -
Page 86: Output Voltage And Limits
LTM4680 PMBus COMMAND DETAILS VIN_UV_WARN_LIMIT The VIN_UV_WARN_LIMIT command sets the value of input voltage measured by the ADC that causes an input under- voltage warning. This warning is disabled until the input exceeds the input startup threshold value set by the VIN_ON command and the unit has been enabled. - Page 87 VOUT_MODE The data byte for VOUT_MODE command, used for commanding and reading output voltage, consists of a 3-bit mode (only linear format is supported) and a 5-bit parameter representing the exponent used in output voltage Read/Write commands. This read-only command has one data byte.
- Page 88 LTM4680 PMBus COMMAND DETAILS VOUT_MARGIN_HIGH The VOUT_MARGIN_HIGH command loads the unit with the voltage to which the output is to be changed, in Volts, when the OPERATION command is set to “Margin High”. The value should be greater than VOUT_COMMAND. The maximum guaranteed value on VOUT_MARGIN_HIGH is 3.6V.
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Page 89: Output Current And Limits
LTM4680 PMBus COMMAND DETAILS MFR_VOUT_MAX The MFR_VOUT_MAX command is the maximum output voltage in volts for each channel, including VOUT_OV_FAULT_ LIMIT. If the output voltages are set to high range (Bit 6 of MFR_PWM_CONFIG set to a 0) MFR_VOUT_MAX is 3.6V. If the output voltage is set to low range (Bit 6 of MFR_PWM_CONFIG set to a 1) the MFR_VOUT_MAX is 2.75V. - Page 90 LTM4680 PMBus COMMAND DETAILS IOUT_OC_FAULT_LIMIT The IOUT_OC_FAULT_LIMIT command sets the value of the peak output current limit, in Amperes. When the control- ler is in current limit, the overcurrent detector will indicate an overcurrent fault condition. The following table lists the –...
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Page 91: Input Current And Limits
LTM4680 PMBus COMMAND DETAILS IOUT_OC_WARN_LIMIT This command sets the value of the output current measured by the ADC that causes an output overcurrent warning in Amperes. The READ_IOUT value will be used to determine if this limit has been exceeded. In response to the IOUT_OC_WARN_LIMIT being exceeded, the device: •... -
Page 92: Temperature
LTM4680 PMBus COMMAND DETAILS TEMPERATURE Power Stage DCR Temperature Calibration DATA DEFAULT COMMAND NAME CMD CODE DESCRIPTION TYPE PAGED FORMAT UNITS NVM VALUE MFR_TEMP_1_GAIN 0xF8 Sets the slope of the external temperature R/W Word 0.995 sensor. 0x3FAE MFR_TEMP_1_OFFSET 0xF9 Sets the offset of the external temperature R/W Word sensor. -
Page 93: Timing
LTM4680 PMBus COMMAND DETAILS In response to the OT_WARN_LIMIT being exceeded, the device: • Sets the TEMPERATURE bit in the STATUS_BYTE • Sets the Overtemperature Warning bit in the STATUS_TEMPERATURE command, and • Notifies the host by asserting ALERT pin, unless masked This command has two data bytes and is formatted in Linear_5s_11s format. -
Page 94: Timing-Off Sequence/Ramp
LTM4680 PMBus COMMAND DETAILS TON_MAX_FAULT_LIMIT The TON_MAX_FAULT_LIMIT command sets the value, in milliseconds, on how long the unit can attempt to power up the output without reaching the output undervoltage fault limit. A data value of 0ms means that there is no limit and that the unit can attempt to bring up the output voltage indefinitely. The maximum limit is 83 seconds. -
Page 95: Precondition For Restart
LTM4680 PMBus COMMAND DETAILS TOFF_MAX_WARN_LIMIT The TOFF_MAX_WARN_LIMIT command sets the value, in milliseconds, on how long the output voltage exceeds 12.5% of the programmed voltage before a warning is asserted. The output is considered off when the V voltage is less than 12.5% of the programmed VOUT_COMMAND value. The calculation begins after TOFF_FALL is complete. A data value of 0ms means that there is no limit and that the output voltage exceeds 12.5% of the programmed voltage indefinitely. -
Page 96: Fault Responses Input Voltage
LTM4680 PMBus COMMAND DETAILS Fault Responses Input Voltage DATA DEFAULT COMMAND NAME CMD CODE DESCRIPTION TYPE PAGED FORMAT UNITS VALUE VIN_OV_FAULT_RESPONSE 0x56 Action to be taken by the device when an R/W Byte 0x80 input supply overvoltage fault is detected. VIN_OV_FAULT_RESPONSE The VIN_OV_FAULT_RESPONSE command instructs the device on what action to take in response to an input over- voltage fault. - Page 97 LTM4680 PMBus COMMAND DETAILS 0xB8–The device shuts down (disables the output) and device attempts to retry continuously, without limitation, until it is commanded OFF (by the RUN pin or OPERATION command or both), bias power is removed, or another fault condition causes the unit to shut down.
- Page 98 LTM4680 PMBus COMMAND DETAILS The UV fault and warn are masked until the following criteria are achieved: 1) The TON_MAX_FAULT_LIMIT has been reached 2) The TON_DELAY sequence has completed 3) The TON_RISE sequence has completed 4) The VOUT_UV_FAULT_LIMIT threshold has been reached 5) The IOUT_OC_FAULT_LIMIT is not present The UV fault and warn are masked whenever the channel is not active.
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Page 99: Fault Responses Output Current
LTM4680 PMBus COMMAND DETAILS TON_MAX_FAULT_RESPONSE The TON_MAX_FAULT_RESPONSE command instructs the device on what action to take in response to a TON_MAX fault. The data byte is in the format given in Table 19. The device also: • Sets the NONE_OF_THE_ABOVE bit in the STATUS_BYTE •... -
Page 100: Fault Responses Ic Temperature
LTM4680 PMBus COMMAND DETAILS Table 17. IOUT_OC_FAULT_RESPONSE Data Byte Contents BITS DESCRIPTION VALUE MEANING Response The LTM4680 continues to operate indefinitely while maintaining the output current at the value set by For all values of bits [7:6], the LTM4680: IOUT_OC_FAULT_LIMIT without regard to the output •... -
Page 101: Fault Responses External Temperature
LTM4680 PMBus COMMAND DETAILS Table 18. Data Byte Contents MFR_OT_FAULT_RESPONSE BITS DESCRIPTION VALUE MEANING Response Not supported. Writing this value will generate a CML fault. For all values of bits [7:6], the LTM4680: Not supported. Writing this value will generate a CML fault •... -
Page 102: Fault Sharing
LTM4680 PMBus COMMAND DETAILS This condition is detected by the ADC so the response time may be up to t CONVERT This command has one data byte. Table 19. Data Byte Contents: TON_MAX_FAULT_RESPONSE, VIN_OV_FAULT_RESPONSE, OT_FAULT_RESPONSE, UT_FAULT_RESPONSE BITS DESCRIPTION VALUE MEANING Response The PMBus device continues operation without interruption. - Page 103 LTM4680 PMBus COMMAND DETAILS Table 20. FAULTn Propagate Fault Configuration The FAULT0 and FAULT1 pins are designed to provide electrical notification of selected events to the user. Some of these events are common to both output channels. Others are specific to an output channel. They can also be used to share faults between channels. BIT(S) SYMBOL OPERATION...
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Page 104: Fault Sharing Response
LTM4680 PMBus COMMAND DETAILS Fault Sharing Response DATA DEFAULT COMMAND NAME CMD CODE DESCRIPTION TYPE PAGED FORMAT UNITS VALUE MFR_FAULT_RESPONSE 0xD5 Action to be taken by the device when the R/W Byte 0xC0 FAULT pin is asserted low. MFR_FAULT_RESPONSE The MFR_FAULT_RESPONSE command instructs the device on what action to take in response to the FAULTn pin being pulled low by an external source. -
Page 105: Identification
LTM4680 PMBus COMMAND DETAILS USER_DATA_00 through USER_DATA_04 These commands are non-volatile memory locations for customer storage. The customer has the option to write any value to the USER_DATA_nn at any time. However, the LTpowerPlay software and contract manufacturers use some of these commands for inventory control. -
Page 106: Fault Warning And Status
LTM4680 PMBus COMMAND DETAILS FAULT WARNING AND STATUS DEFAULT COMMAND NAME CMD CODE DESCRIPTION TYPE PAGED FORMAT UNITS VALUE CLEAR_FAULTS 0x03 Clear any fault bits that have been set. Send Byte SMBALERT_MASK 0x1B Mask activity. Block R/W See CMD Details MFR_CLEAR_PEAKS 0xE3 Clears all peak values. - Page 107 LTM4680 PMBus COMMAND DETAILS would still set bit 6 of STATUS_TEMPERATURE but not assert ALERT. All other supported STATUS_TEMPERATURE bits would continue to assert ALERT if set. Figure 50 shows an example of the Block Write – Block Read Process Call protocol used to read back the present state of any supported status register, again without PEC.
- Page 108 LTM4680 PMBus COMMAND DETAILS STATUS_BYTE Message Contents: STATUS BIT NAME MEANING BUSY A fault was declared because the LTM4680 was unable to respond. This bit is set if the channel is not providing power to its output, regardless of the reason, including simply not being enabled.
- Page 109 LTM4680 PMBus COMMAND DETAILS STATUS_VOUT The STATUS_VOUT command returns one byte of V status information. STATUS_VOUT Message Contents: MEANING overvoltage fault. overvoltage warning. undervoltage warning. undervoltage fault. max warning. TON max fault. TOFF max fault. Not supported (LTM4680 returns 0). The user is permitted to write a 1 to any bit in this command to clear a specific fault.
- Page 110 LTM4680 PMBus COMMAND DETAILS STATUS_INPUT The STATUS_INPUT command returns one byte of V (VINSNS) status information. STATUS_INPUT Message Contents: MEANING overvoltage fault. Not supported (LTM4680 returns 0). undervoltage warning. Not supported (LTM4680 returns 0). Unit off for insufficient V Not supported (LTM4680 returns 0). overcurrent warning.
- Page 111 LTM4680 PMBus COMMAND DETAILS STATUS_CML The STATUS_CML command returns one byte of status information on received commands, internal memory and logic. STATUS_CML Message Contents: MEANING Invalid or unsupported command received. Invalid or unsupported data received. Packet error check failed. Memory fault detected. Processor fault detected.
- Page 112 LTM4680 PMBus COMMAND DETAILS MFR_PADS This command provides the user a means of directly reading the digital status of the I/O pins of the device. The bit assignments of this command are as follows: ASSIGNED DIGITAL PIN OV Fault DD33 UV Fault DD33 Reserved...
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Page 113: Telemetry
LTM4680 PMBus COMMAND DETAILS TELEMETRY DEFAULT COMMAND NAME CODE DESCRIPTION TYPE PAGED FORMAT UNITS VALUE READ_VIN 0x88 Measured input supply voltage. R Word READ_IIN 0x89 Measured input supply current. R Word READ_VOUT 0x8B Measured output voltage. R Word READ_IOUT 0x8C Measured output current. - Page 114 LTM4680 PMBus COMMAND DETAILS READ_IIN The READ_IIN command returns the input current, in Amperes, as measured across the input current sense resistor (see also MFR_IIN_CAL_GAIN). This read-only command has two data bytes and is formatted in Linear_5s_11s format. READ_IOUT The READ_IOUT command returns the average output current in amperes. The IOUT value is a function of: a) the differential voltage measured across the I pins SENSE...
- Page 115 LTM4680 PMBus COMMAND DETAILS MFR_PIN_ACCURACY The MFR_PIN_ACCURACY command returns the accuracy, in percent, of the value returned by the READ_PIN command. There is one data byte. The value is 0.1% per bit which gives a range of ±0.0% to ±25.5%. This read-only command has one data byte and is formatted as an unsigned integer.
- Page 116 LTM4680 PMBus COMMAND DETAILS MFR_TEMPERATURE_2_PEAK The MFR_TEMPERATURE_2_PEAK command reports the highest temperature, in degrees Celsius, reported by the READ_TEMPERATURE_2 measurement. This command is cleared using the MFR_CLEAR_PEAKS command. This read-only command has two data bytes and is formatted in Linear_5s_11s format. MFR_ADC_CONTROL The MFR_ADC_CONTROL command determines the ADC read back selection.
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Page 117: Nvm Memory Commands
LTM4680 PMBus COMMAND DETAILS NVM MEMORY COMMANDS Store/Restore DEFAULT COMMAND NAME CODE DESCRIPTION TYPE PAGED FORMAT UNITS VALUE STORE_USER_ALL 0x15 Store user operating memory to Send Byte EEPROM. RESTORE_USER_ALL 0x16 Restore user operating memory from Send Byte EEPROM. MFR_COMPARE_USER_ALL 0xF0 Compares current command contents Send Byte with NVM. -
Page 118: Fault Logging
LTM4680 PMBus COMMAND DETAILS Fault Logging DATA DEFAULT COMMAND NAME CMD CODE DESCRIPTION TYPE PAGED FORMAT UNITS VALUE MFR_FAULT_LOG 0xEE Fault log data bytes. R Block MFR_FAULT_LOG_ STORE 0xEA Command a transfer of the fault log from RAM Send Byte to EEPROM. - Page 119 LTM4680 PMBus COMMAND DETAILS Table 21. Fault Logging This table outlines the format of the block data from a read block data of the MFR_FAULT_LOG command. Data Format Definitions LIN 11 = PMBus = Rev 1.2, Part 2, section 7.1 LIN 16 = PMBus Rev 1.2, Part 2, section 8. Mantissa portion only BYTE = 8 bits interpreted per definition of this command DATA DATA...
- Page 120 LTM4680 PMBus COMMAND DETAILS CYCLICAL DATA EVENT n Event “n” represents one complete cycle of ADC reads through the MUX at time of fault. Example: If the fault occurs when the ADC is processing (Data at Which Fault Occurred; Most Recent Data) step 15, it will continue to take readings through step 25 and then store the header and all 6 event pages to EEPROM READ_VOUT (PAGE 0)
- Page 121 LTM4680 PMBus COMMAND DETAILS EVENT n-1 (data measured before fault was detected) READ_VOUT (PAGE 0) [15:8] LIN 16 [7:0] LIN 16 READ_VOUT (PAGE 1) [15:8] LIN 16 [7:0] LIN 16 READ_IOUT (PAGE 0) [15:8] LIN 11 [7:0] LIN 11 READ_IOUT (PAGE 1) [15:8] LIN 11 [7:0]...
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Page 122: Block Memory Write/Read
LTM4680 PMBus COMMAND DETAILS Table 22. Explanation of Position_Fault Values POSITION_FAULT VALUE SOURCE OF FAULT LOG 0xFF MFR_FAULT_LOG_STORE 0x00 TON_MAX_FAULT 0x01 VOUT_OV_FAULT 0x02 VOUT_UV_FAULT 0x03 IOUT_OC_FAULT 0x05 TEMP_OT_FAULT 0x06 TEMP_UT_FAULT 0x07 VIN_OV_FAULT 0x0A MFR_TEMP_2_OT_FAULT MFR_INFO Contact the factory for details. MFR_IOUT_CAL_GAIN Contact the factory for details. -
Page 123: Package Description
LTM4680 PACKAGE DESCRIPTION PACKAGE ROW AND COLUMN LABELING MAY VARY AMONG µModule PRODUCTS. REVIEW EACH PACKAGE LAYOUT CAREFULLY . Table 23. LTM4680 BGA Pinout PIN ID FUNCTION PIN ID FUNCTION PIN ID FUNCTION PIN ID FUNCTION PIN ID FUNCTION PIN ID FUNCTION INTV OUT1... - Page 124 LTM4680 PACKAGE DESCRIPTION aaa Z Rev. B For more information www.analog.com...
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Page 125: Revision History
LTM4680 REVISION HISTORY DATE DESCRIPTION PAGE NUMBER 03/19 Updated maximum output voltage of Output Voltage Readback Accuracy to 3.3V 08/19 Added Note 15 to Conditions of V Changed f MIN from 200kHz to 300kHz RANGE Added SHARE_CLK to Leakage Current specification Removed GPIO from Digital Inputs specification Added FAULTn to Digital Inputs specification... -
Page 126: Package Photograph
LTM4680 PACKAGE PHOTOGRAPH DESIGN RESOURCES SUBJECT DESCRIPTION µModule Design and Manufacturing Resources Design: Manufacturing: • Selector Guides • Quick Start Guide • Demo Boards and Gerber Files • PCB Design, Assembly and Manufacturing Guidelines • Free Simulation Tools • Package and Board Level Reliability µModule Regulator Products Search 1.