MAX16067 Datasheet, PDF(18/47 Page) Maxim Integrated Products – 6-Channel, Flash-Configurable System Manager with Nonvolatile Fault Registers

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6-Channel, Flash-Configurable System Manager

with Nonvolatile Fault Registers

ALERT

GPIO1 is configurable as the SMBus alert signal, ALERT.

ALERT asserts when any fault condition occurs. When the

SMBus host sends the ARA (Alert Response Address),

the MAX16067 responds with its slave address and

deasserts ALERT. ALERT is an open-drain output.

Set the ARAEN bit in r40h[4] to â1â to disable the ARA

feature. Under these conditions, the device does not

respond to an ARA on the SMBus line.

FAULT

GPIO2 is configurable as a dedicated fault output,

FAULT. FAULT asserts when an overvoltage or under-

voltage condition occurs on the selected inputs. FAULT

dependencies are set using registers r36h and r37h

(see Table 13). When FAULT depends on more than one

MON_, the fault output asserts when one or more MON_

exceeds a programmed threshold voltage. FAULT acts

independently of the critical fault system, described in

the Critical Faults section. Use r37h[7] to set the polarity

of FAULT.

Manual Reset (MR)

GPIO3 is configurable to act as an active-low manual reset

input, MR. Drive MR low to assert RESET. RESET remains

asserted for the selected reset timeout period after MR

transitions from low to high. When connecting MR to a push-

button, use a pullup resistor. See the Reset Output section

for more information on selecting a reset timeout period.

Watchdog Input (WDI) and Output (WDO)

GPIO4 and GPIO5 are configurable as the watchdog

timer input (WDI) and output, WDO, respectively. See

Table 23 for configuration details. WDO is an open-drain,

active-low output. See the Watchdog Timer section for

more information about the operation of the watchdog

timer.

External Fault (EXTFAULT)

GPIO6 is configurable as the external fault input/output,

EXTFAULT. EXTFAULT asserts if any monitored volt-

age exceeds an overvoltage or undervoltage threshold.

EXTFAULT also asserts if a power-up or power-down

sequencing fault occurs. This signal can be used to

cascade multiple MAX16067s.

Pull EXTFAULT low externally to force the sequencer to

enter a fault state. Under these conditions, all outputs

deassert.

Two configuration bits determine the behavior of the

MAX16067 when EXTFAULT is pulled low by an exter-

nal device. Register bit r72h[5], if set to a â1â, causes

the sequencer state machine to enter the fault state,

deasserting all the outputs when EXTFAULT is pulled

low. When this happens, the flag bit r1Ch[6] is set to

indicate the cause of the fault. If register bit r6Dh[2] is

set in addition to r72h[5], EXTFAULT going low triggers

a nonvolatile fault log operation.

Table 13. FAULT Dependencies

ADDRESS

36h

37h

FLASH

ADDRESS

236h

237h

BIT RANGE

DESCRIPTION

[0]

[1]

[2]

[3]

[4]

[5]

[7:6]

[0]

[1]

[2]

[3]

[4]

[5]

[6]

[7]

FAULT depends on MON1 undervoltage threshold

FAULT depends on MON2 undervoltage threshold

FAULT depends on MON3 undervoltage threshold

FAULT depends on MON4 undervoltage threshold

FAULT depends on MON5 undervoltage threshold

FAULT depends on MON6 undervoltage threshold

Not used

FAULT depends on MON1 overvoltage threshold

FAULT depends on MON2 overvoltage threshold

FAULT depends on MON3 overvoltage threshold

FAULT depends on MON4 overvoltage threshold

FAULT depends on MON5 overvoltage threshold

FAULT depends on MON6 overvoltage threshold

Not used

0 = FAULT is an active-low digital output

1 = FAULT is an active-high digital output

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