Digital Power Supply - Linear Technology DC1978A Manual

DESCRIPTION
The DC1978A is a demonstration system for the LTC
2
quad I C/SMBus/PMBus power supply monitor and con-
troller with EEPROM. The DC1978A demonstrates the
ability of the LTC2974 to monitor, supervise, sequence,
trim, margin and log faults for four power supplies. Each
power supply channel of the LTC2974 monitors current,
voltage and temperature. This demonstration system is
supported by the LTpowerPlay™ graphical user interface
(GUI) that enables complete control of all LTC2974 features.
The DC1978A consists of two circuit boards designed to
work as a pair, DC1809A and DC1810A. The DC1809A
contains all the circuitry needed to insert the LTC2974
into a power system and control four power supplies.
The DC1810A contains four power supplies, two LTC3860
DrMOS supplies and two LTM
configured to be controlled by the LTC2974. Together, these
two boards form a sophisticated four-channel digitally
programmable power supply.
Together, the LTpowerPlay software and DC1978A hardware
system create a powerful development environment for
designing and testing LTC2974 configuration settings.
These settings can be stored in the LTC2974 internal
EEPROM or in a file. This file can later be used to order
preprogrammed devices or to program devices in a pro-
duction environment. The LTpowerPlay software displays
all of the configuration settings and real time measure-
ments from the LTC2974. Telemetry allows easy access
and decoding of the fault log created by the LTC2974. The
LTC2974 on the DC1809A board comes preprogrammed
with the EEPROM values appropriate for the four power
supplies used on the DC1810A. Just plug and play!
Multiple DC1978A board sets can be cascaded together to
form a high channel count power supply (see Multiboard
Arrays). This cascaded configuration demonstrates
features of the LTC2974 which enable timing and fault
information to be shared across multiple LTC2974s allow-
ing for the formation of a single, coherent power supply
control system. This cascaded configuration is supported
®
2974
® 4620 supplies, which are
DEMO MANUAL DC1978A

Digital Power Supply

Manager with EEPROM
by the LTpowerPlay GUI and allows the user to configure
up to nine LTC2974s, thereby controlling up to 36 sepa-
rate power supplies. Larger arrays (>9) of LTC2974s are
supported through programmable I
bus segmentation.
The DC1809A/DC1810A boards are powered by an external
12V power supply. Communication with the LTpowerPlay
software is via the DC1613 USB to I
controller. The following is a checklist of items which can
be obtained from the LTC website or LTC Field Sales.
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• USB to I C/PMBus Controller (DC1613)
• LTpowerPlay Software
• Configuration File (.proj file) for the DC1978A
Design files for this circuit board are available at
http://www.linear.com/demo
LTC2974 Features
2
• I C/SMBus Serial Interface
• PMBus Compliant Command Set
• Configuration EEPROM with CRC
• Black Box Fault Logging to Internal EEPROM
• Differential Input, 16-Bit ΔΣ ADC with Less Than
±0.25% of Total Unadjusted Error
• Four Voltage Servos Precisely Adjust Supply
Voltages Using 10-Bit DACs with Soft Connect
• Monitors Four Output Voltages, Four Output Currents
and One Input Voltage
• Monitors Four External Temperature Sensors and
Internal Die Temperature
• 4-Channel Sequencer, Time Based or Tracking
• Programmable Watchdog Timer
L, LT, LTC, LTM, μModule, PolyPhase, Linear Technology and the Linear logo are registered
trademarks and LTpowerPlay is a trademark of Linear Technology Corporation. All other
trademarks are the property of their respective owners. Protected by U.S. Patents Including
7382303 and 7420359.
LTC2974 Quad
2
C base address or
2
C/SMBus/PMBus
dc1978af
1