MAX34441 Datasheet, PDF (35/53 Pages) Maxim Integrated Products – PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller

PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
TON_DELAY (60h)
TON_DELAY sets the time, in milliseconds, from when a START condition is received (a valid OPERATION command
or through the CONTROL pin when enabled) until the PSEN output is asserted. The undervoltage fault and warning are
masked off during TON_DELAY. The 2 data bytes are in DIRECT format.
TON_MAX_FAULT_LIMIT (62h)
The TON_MAX_FAULT_LIMIT sets an upper time limit, in milliseconds, from when the TON_DELAY and the PSEN
output are asserted until the output voltage crosses the VOUT_UV_FAULT_LIMIT threshold. The 2 data bytes are in
DIRECT format. If the value is 0, the power supply is not sequenced by the device and the associated PSEN output
remains deasserted; voltage and current monitoring is disabled. In response to the TON_MAX_FAULT_LIMIT being
exceeded, the device does the following:
1) Sets the NONE OF THE ABOVE bit in STATUS_BYTE.
2) Sets the NONE OF THE ABOVE and VOUT bits in STATUS_WORD.
3) Sets the TON_MAX_FAULT bit in STATUS_VOUT.
4) Responds as specified in the MFR_FAULT_RESPONSE.
5) Notifies the host using ALERT assertion (if enabled in MFR_MODE).
Table 19. TON_MAX_FAULT_LIMIT
TON_MAX_FAULT_LIMIT VALUE
8000h to FFFFh
0000h
0001h to 7FFFh
DEVICE RESPONSE (FOR THE ASSOCIATED PAGE)
Negative values are invalid.
Channel off (PSEN remains deasserted with no monitoring).
Channel on and sequencing enabled.
TOFF_DELAY (64h)
The TOFF_DELAY sets the time, in milliseconds, from when a STOP condition is received (a soft-off OPERATION com-
mand or through the CONTROL pin when enabled) until the PSEN output is deasserted. When commanded to turn off
immediately (either through the OPERATION command or the CONTROL pin), the TOFF_DELAY value is ignored. The
2 data bytes are in DIRECT format.
STATUS_BYTE (78h)
The STATUS_BYTE command returns 1 byte of information with a summary of the most critical faults. A value of 1 indi-
cates that a fault or warning event has occurred and a 0 indicates otherwise. Bits for unsupported features are reported
as 0. The STATUS_BYTE cannot be restored by the RESTORE_DEFAULT_ALL command. The STATUS_BYTE message
content is described in Table 20. This command is read-only.
Table 20. STATUS_BYTE
BIT
BIT NAME
MEANING
7:6
0
These bits always return a 0.
5
VOUT_OV
An overvoltage fault has occurred.
4
IOUT_OC
An overcurrent fault has occurred.
3
0
This bit always returns a 0.
2
TEMPERATURE A temperature fault or warning has occurred.
1
CML
A communication, memory, or logic fault has occurred.
0
NONE OF THE ABOVE A fault or warning not listed in bits [7:1] has occurred.
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