Rainbow Electronics MAX34441 - Manual (Page 35)

PMBus 5-Channel Power-Supply Manager
and Intelligent Fan Controller
MAX34441
35
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).
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 19. TON_MAX_FAULT_LIMIT
Table 20. STATUS_BYTE
TON_MAX_FAULT_LIMIT VALUE DEVICE RESPONSE (FOR THE ASSOCIATED PAGE)
8000h to FFFFh Negative values are invalid.
0000h Channel off (PSEN remains deasserted with no monitoring).
0001h to 7FFFh Channel on and sequencing enabled.
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.