MAX6872ETJ+T Datasheet MAX6873ETJ+, MAX6872ETJ+T, MAX6873ETJ+T | P13-P15

MAX6872/MAX6873

EEPROM-Programmable, Hex/Quad,

Power-Supply Sequencers/Supervisors

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Table 1. Programmable Features

FEATURE DESCRIPTION

High-Voltage Input

(IN1)

• Primary undervoltage threshold

• Secondary overvoltage or undervoltage threshold

• +2.5V to +13.2V threshold in 50mV increments

• +1.25V to +7.625V threshold in 25mV increments

Bipolar-Voltage Input

(IN2)

• Primary undervoltage threshold

• Secondary overvoltage or undervoltage threshold

• ±2.5V to ±15.25V threshold in 50mV increments

• ±1.25V to ±7.625V threshold in 25mV increments

Positive-Voltage Input

IN3–IN6 (MAX6872),

IN3–IN4 (MAX6873)

• Primary undervoltage threshold

• Secondary overvoltage or undervoltage threshold

• +1V to +5.5V threshold in 20mV increments

• +0.5V to +3.05V threshold in 10mV increments

Programmable Outputs

PO1–PO4 (MAX6872),

PO1–PO2 (MAX6873)

• Active high or active low

• Open-drain, weak pullup, or charge-pump output

• Weak pullup to IN3–IN6 (IN3 or IN4 for MAX6873) or ABP

• Dependent on MR, MARGIN, IN_, GPI1–GPI4 , WD1 and WD2, and/or PO_

• Programmable timeout periods of 25µs, 1.5625ms, 6.25ms, 25ms, 50ms, 200ms, 400ms, or 1.6s

Programmable Outputs

PO5–PO8 (MAX6872),

PO3–PO5 (MAX6873)

• Active high or active low

• Open-drain, weak pullup, or push-pull output

• Weak pullup to IN3–IN6 (IN3 or IN4 for MAX6873) or ABP

• Push-pull to IN3–IN6 (IN3 or IN4 for MAX6873)

• Dependent on MR, MARGIN, IN_, GPI1–GPI4 , WD1 and WD2, and/or PO_

• Programmable timeout periods of 25µs, 1.5625ms, 6.25ms, 25ms, 50ms, 200ms, 400ms, or 1.6s

General-Purpose Logic

Inputs (GPI1–GPI4)

• Active high or active low logic levels

• Configure GPI_ as inputs to watchdog timers or programmable output stages

Watchdog Timers

• Clear dependent on any combination of one GPI_ input and one programmable output, a GPI_ input

only, or a programmable output only

• Initial watchdog timeout period of 6.25ms, 25ms, 100ms, 400ms, 1.6s, 6.4s, 25.6s, or 102.4s

• Normal watchdog timeout period of 6.25ms, 25ms, 100ms, 400ms, 1.6s, 6.4s, 25.6s, or 102.4s

• Watchdog enable/disable

• Initial watchdog timeout period enable/disable

Manual Reset Input

(MR)

• Forces PO_ into the active output state when MR = GND

• PO_ deassert after MR releases high and the PO_ timeout period expires

• PO_ cannot be a function of MR only

Margining Input

(MARGIN)

• Holds PO_ in existing state or asserts PO_ to a programmed output state, independent of changes in

monitored inputs or watchdog timers, when MARGIN = GND

• Overrides MR when both assert at the same time

Write Disable • Locks user EEPROM based on PO_

Configuration Lock • Locks configuration EEPROM

where V

is the desired threshold voltage and x is the

decimal code for the desired threshold (Table 3).

IN3–IN6

IN3–IN6 offer positive voltage detectors monitor volt-

ages from +1V to +5.5V in 20mV increments, or +0.5V

to +3.05V in 10mV increments. Use the following equa-

tions to set the threshold voltages for IN_:

where V

is the desired threshold voltage and x is the

decimal code for the desired threshold (Table 4). For

the +1V to +5.5V range, x must equal 225 or less, oth-

for V to V range

=++

− .

. .

001

05 305

for V to V range

=++

−

002

155

for V to V range

=++

− .

. .

125

0 025

1 25 7 625

for V to V range

=++

− .

. .

005

2 5 15 25

for V to V range

()

−−

−− .

. .

125

0 025

1 25 7 625

MAX6872/MAX6873

EEPROM-Programmable, Hex/Quad,

Power-Supply Sequencers/Supervisors

14 ______________________________________________________________________________________

Table 3. IN2 Threshold Settings

ADDRESS

EEPROM

MEMORY

ADDRESS

BIT

RANGE

DESCRIPTION

01h 8001h [7:0]

IN2 primary undervoltage detector threshold (V2A) (see equations in the Bipolar-Voltage

Input (IN2) section).

07h 8007h [7:0]

IN2 secondary undervoltage/overvoltage detector threshold (V2B) (see equations in the

Bipolar-Voltage Input (IN2) section).

0Ch 800Ch [1]

IN2 secondary overvoltage/undervoltage selection:

0 = overvoltage threshold. 1 = undervoltage threshold.

0Dh 800Dh [7:6]

IN2 range selection:

00 = -2.5V to -15.25V range in 50mV increments.

01 = -1.25V to -7.625V range in 25mV increments.

10 = +2.5V to +15.25V range in 50mV increments.

11 = +1.25V to +7.625V range in 25mV increments.

Table 2. IN1 Threshold Settings

ADDRESS

EEPROM

MEMORY

ADDRESS

BIT

RANGE

DESCRIPTION

00h 8000h [7:0]

IN1 primary undervoltage detector threshold (V1A) (see equations in the High-Voltage Input

(IN1) section).

06h 8006h [7:0]

IN1 secondary undervoltage/overvoltage detector threshold (V1B) (see equations in the

High-Voltage Input (IN1) section).

0Ch 800Ch [0]

IN1 secondary overvoltage/undervoltage selection:

0 = overvoltage threshold. 1 = undervoltage threshold.

0Dh 800Dh [0]

IN 1 r ang e sel ecti on:

0 = 2.5V to 13.2V r ang e i n 50m V i ncr em ents. 1 = 1.25V to 7.625V r ang e i n 25m V i ncr em ents.

MAX6872/MAX6873

EEPROM-Programmable, Hex/Quad,

Power-Supply Sequencers/Supervisors

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Table 4. IN3–IN6 Threshold Settings

ADDRESS

EEPROM

MEMORY

ADDRESS

BIT

RANGE

DESCRIPTION

02h 8002h [7:0] IN3 primary undervoltage detector threshold (V3A) (see equations in the IN3–IN6 section).

03h 8003h [7:0] IN4 primary undervoltage detector threshold (V4A) (see equations in the IN3–IN6 section).

04h 8004h [7:0]

IN5 (MAX6872 only) primary undervoltage detector threshold (V5A)