72V, Overvoltage-Protection Switches/

Limiter Controllers with an External MOSFET

6

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Pin Description

PIN

NAME

FUNCTION

11

1

1

IN

Positive Supply Voltage. Connect IN to the positive side of the input voltage. Bypass IN

with a 10µF capacitor to GND.

22

2

2

SHDN

Shutdown Input. Drive SHDN low to force GATE low and turn off the external n-channel

MOSFET. Drive SHDN low and then high to reset the overvoltage-condition latch. SHDN

is internally pulled to GND with 1µA of current. Connect SHDN to IN for normal operation.

33

3

3

OVSET

Overvoltage-Threshold Adjustment Input. Connect OVSET to an external resistive

voltage-divider network to adjust the desired overvoltage-disable or overvoltage-limit

threshold. Connect the resistor network to the input side (drain) of the n-channel

MOSFET for overvoltage switch turn-off applications or to the output side (source) of the

n-channel MOSFET for overvoltage-limiting applications (MAX6495/MAX6496/MAX6499).

4

5

5

5

GND

Ground

5

6

6

6

GATE

Gate-Driver Output. Connect GATE to the gate of the external n-channel MOSFET switch.

GATE is the output of a charge pump with a 100µA pullup current to 10V (typ) above IN

during normal operation. GATE is quickly clamped to OUTFB during an overvoltage

condition. GATE pulls low when SHDN is low.

67

7

7

OUTFB

Output-Voltage-Sense Input. Connect OUTFB to the source of the external n-channel

MOSFET switch.

—

4

—

—

GATEP

p-Channel Gate-Driver Output. Connect GATEP to the gate of an external p-channel

MOSFET to provide low-drop reverse-voltage protection. GATEP is biased to ensure that

the p-channel MOSFET is on during normal operating modes, the gate-to-source is not

overstressed during load-dump/overvoltage conditions, and the p-channel MOSFET is

off during reverse-battery conditions.

—

8

——

N.C.

No Connection. Not internally connected.

—

—

4

—

POK

Power-OK Output. POK is an open-drain output. POK remains low while POKSET is

below the internal POKSET threshold. POK goes high impedance when POKSET goes

above the internal POKSET threshold. Connect POK to an external pullup resistor.

—

—

8

—

POKSET

Power-OK Threshold-Adjustment Input. POK remains low while POKSET is below the

internal POKSET threshold (1.18V). POK goes high impedance when POKSET goes

above the internal POKSET threshold (1.24V). Connect a resistive divider from OUTFB

to POKSET to adjust the desired undervoltage threshold.

—

——

4

CLEAR

Latch Clear Input. Connect CLEAR to a logic-high to latch the device off after an

to reset the output latch. Connect CLEAR to GND to make the latch transparent.

—

——

8

UVSET

Undervoltage-Threshold Adjustment Input. Connect UVSET to an external resistive

voltage-divider network to adjust the desired undervoltage threshold.

—

——

—

EP

Exposed Pad. EP is internally connected to GND. Connect EP to the ground plane to

provide a low thermal-resistance path from the IC junction to the PC board. Do not use

as the primary electrical connection to GND.