4-116

TELCOM SEMICONDUCTOR, INC.

TC25C25

TC35C25

BICMOS PWM CONTROLLERS

can range from >1

Ω to <900Ω. Dead time increases when

for dead time resistor value.

OSCILLATOR FREQUENCY AND OUTPUT DEAD TIME

1

the output dead time when both of the output drivers are

current.

Select a capacitor in the range of 100 pF to 1000 pF for

1.5

1mA

TO OUTPUT

SHUTDOWN

IS

VON = 9.2V

VOFF = 7V

75

µA

7V

9.2V

IS = STARTUP CURRENT

VIN

V+

IN

CT

5

DISCH

7

RT

6

+

–

1.5V

3

SYNC

VDD

ICHARGE ≈

1.5V

RT

1/FO

TD

3V

.5V

ON-TIME

(TCHG)

PIN 5

OUTPUT DEAD TIME (TD)

PIN 4

RD

3V

0.5V

UNDERVOLTAGE LOCKOUT SECTION

The typical turn on threshold is 9.2V for operation of this

family of PWM Controllers. When supply voltage at pin 15

drops below 7V, after normal operation above 9.2V, lockout

occurs and both output drives to pin 11 and 14 are termi-

nated.