PMBus COMMAND DETAILS
FREQUENCY_SWITCH
The FREQUENCY_SWITCH command sets the switching frequency, in kHz, of the LTM4681.
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
The part must be in the OFF state to process this command. The RUN pin must be low or both channels must be
commanded off. If the part is in the RUN state and this command is written, the command will be NACK'd and a BUSY
fault will be asserted. When the part is commanded off and the frequency is changed, a PLL_UNLOCK status may be
detected as the PLL locks onto the new frequency.
This command has two data bytes and is formatted in Linear_5s_11s format.
VOLTAGE
Input Voltage and Limits
COMMAND NAME
CMD CODE DESCRIPTION
VIN_OV_FAULT_LIMIT
0x55
VIN_UV_WARN_LIMIT
0x58
VIN_ON
0x35
VIN_OFF
0x36
MFR_ICHIP_CAL_GAIN
0xF7
VIN_OV_FAULT_LIMIT
The VIN_OV_FAULT_LIMIT command sets the value of the input voltage measured by the ADC, in volts, that causes
an input overvoltage fault.
This command has two data bytes in Linear_5s_11s format.
Input supply overvoltage fault limit.
Input supply undervoltage warning limit.
Input voltage at which the unit should start
power conversion.
Input voltage at which the unit should stop
power conversion.
The resistance value of the V
pin filter
IN
element in milliohms onboard
For more information
DATA
TYPE
PAGED
FORMAT
R/W
N
L11
Word
R/W
N
L11
Word
R/W
N
L11
Word
R/W
N
L11
Word
R/W
N
L11
Word
www.analog.com
LTM4681
DEFAULT
UNITS
NVM
VALUE
V
Y
15.5
0xD3E0
V
Y
4.65
0xD12A
V
Y
4.75
0xD130
V
Y
4.5
0xD120
mΩ
Y
1000
0x03E8
Rev. A
93
Need help?
Do you have a question about the Linear ADI Power LTM4681 and is the answer not in the manual?
Questions and answers