trans lated , stored , or used without the prior w ritten co nsent of the co p yrig ht ow ner. To the best of its kno w led g e, austriamicros ystems asserts that the

informati on co ntai ned in this p ub licati on is a ccurate and correct.

Re vis ion 1. 0, 08/27/0 3

Key Features

-

Vbat monitor with fault signal generation when Vbat is

out of operative range

-

Vdd monitor with intelligent reset generation based on

Vdd level

-

Internal protections against transients up to 40V

-

Over-temperature monitor

-

Power down mode

General Description

This block provides a stable regulated output voltage

starting from a battery input with the maximum current load

allowed by the thermal package limitation (worst case

20mA). Higher current can be delivered using an external

NPN transistor. External capacitors are required on the

regulated line (VDD) and the battery supply voltage (VBAT).

Battery input is monitored and a fault signal becomes active

when VBAT is out of its operative range (an hysteresis is

provided). VDD also is monitored and a fault signal

becomes active when VDD is below a defined voltage

threshold (an hysteresis is provided). Internal protections

are designed to handle transients up to 40V. An external

45V zener diode between VBAT and ground with a 500

Ω

resistor in series with the battery supply and the VBAT pin

is required to protect the device from power transients. An

external blocking diode is required to provide reverse

battery protection. Over-temperature monitor turns off the

circuit when the die temperature exceeds the fixed

threshold. The circuit has a power-down mode to permit

very low standby currents.

Typical Application Diagrams

VBAT_FAULT

VDD_FAULT

TEMP_FAULT

PD

VBAT

BC

GND

BATTERY

VOLTAGE

REGULATOR

VDD

CONFIGURATION FOR LOAD

CURRENT < 20 mA

VBAT_FAULT

VDD_FAULT

TEMP_FAULT

PD

VBAT

BC

GND

BATTERY

VOLTAGE

REGULATOR

VDD

CONFIGURATION FOR LOAD

CURRENT > 20 mA

Key Parameters

Symbol

Min.

Max.

Notes

Battery Supply Voltage

VBAT

7V

18V

Load dump 42V.

Output Voltage

VDD

4.75V

5.25V

Recommended external capacitor

≥100nF.

20mA max. load, higher current with

external transistor.

Temperature Threshold

Toff

160° C

Hysteresis >10 degrees

Ambient Temperature

Tamb

-40° C

85° C

For detailed information:

info@austriamicrosystems.com

http://www.austriamicrosystems.com/

Voltage Regulator