UDN2916A
PIN CONNECTION
(Top view)
PIN FUNCTIONS
N°
1;2
3;23
4;22
Name
OUTPUT A
SENSE RESISTOR
COMPARATOR INPUT
See pins 5;21
Connection to Lower Emitters of Output Stage for Insertion of Current Sense
Resistor
Input connected to the comparators. The voltage across the sense resistor is
feedback to this input throught the low pass filter RC CC. The higher power
transistors 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 R
T
C
T
(t
off
= 1.1 R
T
C
T
). See fig. 1.
Output Connection. The output stage is a ”H” bridge formed by four
transistors and four diodes suitable for switching applications.
See pins 7;18
Ground Connection. With pins 6 and 19 also conducts heat from die to
printed circuit copper.
See INPUT 1 (pins 9;17)
These pins and pins 8;20 (INPUT 0) are logic inputs which select the outputs
of the comparators to set the current level. Current also depends on the
sensing resistor and reference voltage. See Funcional Description.
This TTL-compatible logic inputs 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.
A voltage applied to this pin sets the reference voltage of the comparators,
this determining the output current (also thus depending on R
s
and the two
inputs INPUT 0 and INPUT 1).
A parallel RC network connected to this pin sets the OFF time of the higher
power transistors. The pulse generator is a monostable triggered by the
output of the comparators (t
off
= 1.1 R
T
C
T
).
Supply Voltage Input for Logic Circuitry
Supply Voltage Input for the Output Stages.
Function
5;21
6;19
7;18
8;20
9;17
OUTPUT B
GROUND
GROUND
INPUT 0
INPUT 1
10;16
PHASE
11;15
REFERENCE VOLTAGE
12;14
RC
13
24
2/8
V
ss
- LOGIC SUPPLY
V
S
- LOAD SUPPLY
STMICROELECTRONICS [ STMICROELECTRONICS ]
