Device diagrams

6/26

Table 2.

Pin functions

Name

Function

OUTB

Output connection (with pin OUT A). The output stage is a "H" bridge formed by four

transistors and four diodes suitable for switching applications.

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 the

Supply voltage input for half output stage

GND

Ground connection. In SO20 and power DIP these pins also conduct heat from die to

printed circuit copper.

Supply voltage input for logic circuitry

IN1

This pin and pin IN0 are logic inputs which select the outputs of three comparators to set

the current level. Current also depends on the sensing resistor and reference voltage.

See

Table 8: Truth table.

PHASE

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

high level causes current to flow from OUT A (source) to OUT B (sink). A Schmidt trigger

on this input provides good noise immunity and a delay circuit prevents output stage

short circuits during switching.

IN0

See IN1

COMPARATOR INPUT

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

feedback to this input through the low pass filter RCCC. The lower power transistor are

disabled when the sense voltage exceeds the reference voltage of the selected

REFERENCE

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

output current.

Supply voltage input for half output stage

OUTA

See pin OUT B

SENSE RESISTOR

Connection to lower emitters of output stage for insertion of current sense resistor

ALARM

PRE-ALARM

Table 3.

Device comparison table

Device

Current

Package

Alarm

Pre-alarm

TEA3718SDP

1.5 A

Power DIP 12+2+2

Not connected

TEA3718SFP

1.5 A

SO20

Connected

TEA3718SP

1.5 A

Multiwatt 15

Connected

TEA3718DP

1.5 A

Power DIP 12+2+2

Not connected