Automotive Micropower Linear Regulators

with Supervisor

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9

Pin Description (continued)

PIN

MAX6765/

MAX6766

MAX6767/

MAX6768

MAX6769/

MAX6770

MAX6771/

MAX6772

MAX6773/

MAX6774

NAME

FUNCTION

—4

—

—

—

HOLD

Active-Low Regulator Hold Input. When HOLD is forced

low, OUT remains on even if ENABLE is pulled low. To

shut down the regulator, release HOLD after ENABLE is

pulled low. Connect HOLD to OUT or leave

unconnected if unused. HOLD is internally connected

to OUT through a 1.8µA current source.

—

6

6

6

6

SET

Feedback Input for Setting the Output Voltage. Connect

SET to GND to select the preset output voltage.

Connect to an external resistive divider for

adjustable output operation.

——

4

—

—

RESETIN

Adjustable Reset Threshold Input. Connect to a

resistive divider to set the desired threshold.

———

3

—

ENABLE1

Active-High Enable Input 1. Drive ENABLE1 high to turn

on the regulator. ENABLE1 is internally connected to

ground through a 0.6µA current sink.

———

4

—

ENABLE2

Active-High Enable Input 2. Drive ENABLE2 high to turn

on the regulator. ENABLE2 is internally connected to

ground through a 0.6µA current sink.

———

—4

WDI

Watchdog Timer Input. If WDI remains high or low for

longer than the watchdog timeout period, the

internal watchdog timer expires and the reset output

asserts for the reset timeout period. The internal

watchdog timer clears whenever a reset is asserted or

WDI sees a rising or falling edge. The watchdog timer

cannot be disabled. Do not leave WDI unconnected.

EP

EP

EP

EP

EP

—

Exposed Paddle. 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 PCB.

Do not use as the electrical connection to GND.

Detailed Description

The MAX6765–MAX6774 low-quiescent-current, high-

voltage linear regulators operate from a 4V to 72V input

voltage and deliver more than 100mA of load current.

The MAX6765–MAX6774 include an integrated µP reset

circuit that monitors the regulator output voltage and

asserts a reset output when OUT falls below a threshold

limit, and includes an internally fixed or adjustable reset

timeout using a capacitor from TIMEOUT to ground. All

devices are available in a preset output-voltage option of

+1.8V, +2.5V, +3.3V, and +5V. The output voltage of the

MAX6767–MAX6774 is adjustable from +1.8V to +11V

using a resistive divider at SET. The MAX6773/MAX6774

include a watchdog timer (WDI) with a 1.6s (typ) watch-

dog timeout period. The MAX6769/MAX6770 feature an

adjustable reset threshold using a resistive divider

between the monitored voltage, RESETIN, and GND; see

the Functional Diagrams.

The MAX6771/MAX6772 provide dual enable inputs

(ENABLE1 and ENABLE2) to turn on and off the regula-

tor either through an ignition switch or a bus transceiver.