PIN FUNCTIONS

N

°

Name

Function

1

UTPUT B

Output Connection (with pin 15). The output stage is a ”H” bridge formed by four

transistors and four diodes suitable for switching applications.

2

PULSE TIME

A parallel RC network connected to this pin sets the OFF time of the lower power

transistors. The pulse generator is a monostable triggered by the rising edge of

3

SUPPLY VOLTAGE B

Supply Voltage Input for Half Output Stage

See also pin 14.

4

GROUND

Ground Connection. With pins 5, 12 and 13 also conducts heat from die to

printed circuit copper.

5

GROUND

See pin 4.

6

LOGIC SUPPLY

Supply Voltage Input for Logic Circuitry

7

INPUT 1

This pin and pin 9 (INPUT 0) are logic inputs which select the outputs of the

three comparators to set the current level. Current also depends on the sensing

resistor and reference voltage. See truth table.

8

PHASE

This TTL-compatible logic input sets the direction of current flow through the

load. A high level causes current to flow from OUTPUT A (source) to OUTPUT

B (sink). A schmitt trigger on this input provides good noise immunity and a delay

circuit prevents output stage short circuits during switching.

9

INPUT 0

See INPUT 1 (pin 7) .

10

COMPARATOR

INPUT

Input connected to the three comparators. The voltage across the sense resistor

transistor are disabled when the sense voltage exceeds the reference voltage of

the selected comparator. When this occurs the current decays for a time set by

11

REFERENCE

A voltage applied to this pin sets the reference voltage of the three comparators,

INPUT 0 and INPUT 1).

12

GROUND

See pin 4.

13

GROUND

See pin 4.

14

SUPPLY VOLTAGE A

Supply Voltage Input for Half Output Stage. See also pin 13.

15

OUTPUT A

See pin 1.

16

SENSE RESISTOR

Connection to Lower Emitters of Output Stage for Insertion of Current Sense

Resistor

TRUTH TABLE

Inpu t 0 (pin 9)

Input 1 (pin 7)

H

L

H

L

H

H

L

L

No Current

Low Current

Medium Current

High Current

PBL3717A

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