MC33164/MC34164

PRODUCT DA T ABOOK 1996/1997

7

Copyright © 1997

Rev. 1.5

11/97

TYPICAL APPLICATION CIRCUITS

FIGURE 8. — LOW-VOLTAGE MICROPROCESSOR RESET

POWER

SUPPLY

1.2 V

REF

RESET

2

1.0k

1

3

FIGURE 9. — VOLTAGE MONITOR

FIGURE 7. — SWITCHING THE LOAD OFF WHEN

BATTERY VOLTAGE REACHES BELOW 4.3V

A time delayed reset can be accomplished with the addition of C

DLY

.

For systems with extremely fast power supply rise times (< 500ns) it

is recommended that the RC

V

POWER

SUPPLY

1.2 V

REF

MICROPROCESSOR

CIRCUIT

RESET

C

DLY

R

2

1

3

1.2 V

REF

LOAD

RESET

2

4

1

1.2 V

REF

2

270

4.3V

V

CC

R

L

SMP60N03-10L

1

3

FIGURE 10. — MOSFET LOW-VOLTAGE GATE DRIVE PROTECTION

Overheating of the logic level power MOSFET due to insufficient

gate voltage can be prevented with the above circuit. When the

input signal is below the 4.3 volt threshold of the MC34164, its

output grounds the gate of the L

t

V

TH(MPU)

V

IN

1 -

1