MAX6872/MAX6873
EEPROM-Programmable, Hex/Quad,
Power-Supply Sequencers/Supervisors
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Forcing Programmable
Outputs High During Power-Up
A weak 10µA pulldown holds all programmable outputs
low during power-up until ABP exceeds the undervolt-
age lockout (UVLO) threshold. Applications requiring a
guaranteed high programmable output for ABP down to
GND require external pullup resistors to maintain the
logic state until ABP exceeds UVLO. Use 20kΩ resis-
tors for most applications.
Driving High-Side MOSFET
Switches with the MAX6872/MAX6873
High-side MOSFET switches are commonly used in
power-supply sequencing applications. First, configure
the programmable output of the MAX6872/MAX6873 as
an active-low charge-pump output and set the condi-
tions to assert this output. Connect the programmable
output to the gate of an n-channel MOSFET. As the
conditions to deassert this output are met, the output
deasserts high (V
ABP
+5V), turning on the FET, thus
allowing the voltage on the drain to pass through to the
downstream device (see Figure 9).
Table 27. Fault Registers (60h–62h)
DESCRIPTION
[0] 1 = IN1 falls below primary undervoltage threshold.
[1] 1 = IN2 falls below primary undervoltage threshold.
[2] 1 = IN3 falls below primary undervoltage threshold.
[3] 1 = IN4 falls below primary undervoltage threshold.
[4] 1 = IN5 (MAX6872 only) falls below primary undervoltage threshold.
[5] 1 = IN6 (MAX6872 only) falls below primary undervoltage threshold.
60h
[7:6] Not used.
[0]
1 = IN1 falls below secondary undervoltage threshold or rises above secondary overvoltage threshold,
depending on the settings in register 0Ch (see Tables 2, 3, and 4).
[1]
1 = IN2 falls below secondary undervoltage threshold or rises above secondary overvoltage threshold,
depending on the settings in register 0Ch (see Tables 2, 3, and 4).
[2]
1 = IN3 falls below secondary undervoltage threshold or rises above secondary overvoltage threshold,
depending on the settings in register 0Ch (see Tables 2, 3, and 4).
[3]
1 = IN4 falls below secondary undervoltage threshold or rises above secondary overvoltage threshold,
depending on the settings in register 0Ch (see Tables 2, 3, and 4).
[4]
1 = IN5 (MAX6872 only) falls below secondary undervoltage threshold or rises above secondary
overvoltage threshold, depending on the settings in register 0Ch (see Tables 2, 3, and 4).
[5]
1 = IN6 (MAX6872 only) falls below secondary undervoltage threshold or rises above secondary
overvoltage threshold, depending on the settings in register 0Ch (see Tables 2, 3, and 4).
61h
[7:6] Not used.
[0] 1 = WD1 asserted.
[1] 1 = WD2 asserted.
[2] 1 = GPI1 asserted.
[3] 1 = GPI2 asserted.
[4] 1 = GPI3 asserted.
[5] 1 = GPI4 asserted.
[6] 1 = MR asserted.
62h
[7] Not used.
