4-121

TELCOM SEMICONDUCTOR, INC.

7

6

5

4

3

1

2

8

Symbol

Parameter

Test Conditions

Min

Typ

Max

Unit

Output Stage (Cont.)

Output High Level

V

Output High Level

V

Output Rise Time

50

150

nsec

Output Fall Time

50

150

nsec

Undervoltage Lockout

Start-Up

Threshold

7.15

7.7

8.25

V

Threshold Hysteresis

0.5

0.75

1

V

Supply

2.7

3.8

mA

Pin No.

(16-Pin PDIP)

Symbol

Description

1

Soft Start Adjust / Current Limit. For setting the peak current threshold of sense inputs (pins

3 and 4). Second function of this pin is Soft-Start Adjust.

Reference supply output of 5.1 volts. It can supply a minimum of 10mA.

– Current Sense Input. Inverting input for sensing peak current of the pass transistor

through series sense current monitor resistor.

+ Current Sense Input. Non-inverting input used in conjunction with pin 3. This senses the

positive end of current monitor resistor.

5

+ ERROR AMP IN

+ Error Amp In. Non-inverting input for output voltage regulation.

6

– ERROR AMP IN

– Error Amp In. Inverting input of the amplifier for the reference voltage.

7

CMPTR

For compensation of the feedback loop response.

input. Second function is for setting crossover dead time of pin 11and 14 outputs.

10

SYNC

For PWM controller oscillator synchronization of two or more controllers. or as a clock input

to sync oscillator from external signal.

11

OUTPUT A

A output drive of phase A from push pull transistors.

12

GND

Ground return for all input and output pins.

13

Supplies power to operate the output drivers only.

14

OUTPUT B

Output of phase B from push pull transistors.

15

Voltage bias supply for all TC170 circuits except the output transistors.

16

SHUTDOWN

Input pin to disable both output drives to 0V OFF.

PIN CONFIGURATIONS (DIP and SOIC)

TC170

CPE

SHDN

VDD

SOFT START/

ILIM

OUTPUT B

VREF

– I SENSE IN

+ I SENSE IN

+ ERROR AMP IN

CMPTR

GND

OUTPUT A

SYNC

RO

OUT

– ERROR AMP IN

NOTE: Outputs LOW in "OFF" state.

VIN

CO

1

2

3

4

16

15

14

13

5

6

7

12

11

10

9

8

ACOM

1

2

3

4

15

16

14

13

5

6

7

12

11

10

9

8

TC170COE

BUF

–

VSS

CINT

+

–

VREF

CREF

CREF

CAZ

CMPTR OUT

A

DIGITAL GND

B

VDD

+

+

VIN

VIN

VREF

–

CMOS CURRENT MODE

PWM CONTROLLER

TC170

PIN DESCRIPTION