3966
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
FUNCTIONAL BLOCK DIAGRAM
LOGIC
LOAD
SUPPLY
SUPPLY
V
CC
PHASE
PHASE
2
1
V
BB
UVLO
& TSD
UVLO
& TSD
ENABLE
ENABLE
2
1
CURRENT-SENSE
COMPARATOR
CURRENT-SENSE
COMPARATOR
SENSE
SENSE
2
1
BLANKING
GATE
BLANKING
GATE
1
2
1
PWM LATCH
R
+
–
2
PWM LATCH
R
+
–
1
2
Q
S
Q
S
÷4
GROUND
OSC
R
R
2S
1S
RC
C
T
R
T
REFERENCE
Dwg. FP-036-6
TRUTH TABLE
A3966SA (DIP)
PHASE ENABLE OUTA
OUTB
Off
L
16 ENABLE
SENSE
OUT
1
2
3
4
1
1
X
H
L
H
L
L
Off
H
L
15 PHASE
1B
1
H
LOAD
SUPPLY
14 OUT
1A
X = Irrelevant
REFERENCE
RC
V
13
12
GROUND
GROUND
V
REF
BB
5
6
RC
LOGIC
SUPPLY
V
11 OUT
2A
CC
OUT
2B
PHASE
2
7
8
10
9
SENSE
2
ENABLE
2
Dwg. PP-066-2
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1998, 2003 Allegro MicroSystems, Inc.
2
ALLEGRO [ ALLEGRO MICROSYSTEMS ]
