3953
FULL-BRIDGE
PWM MOTOR DRIVER
FUNCTIONAL BLOCK DIAGRAM
LOGIC
SUPPLY
6 VCC
MODE 14
PHASE 7
ENABLE 8
BRAKE 1
GROUND
4
5
SLEEP &
STANDBY MODES
UVLO
& TSD
9
10 15
16
VBB
VCC
BLANKING
PWM LATCH
R
Q
S
RC
3
CT
RT
+–
VTH
2
REF
11
SENSE
RS
12
13
GROUND
Dwg. FP-036-2A
BRAKE
H
H
H
H
H
H
L
L
ENABLE
H
H
L
L
L
L
X
X
X = Irrelevant
PHASE
X
X
H
H
L
L
X
X
MODE
H
L
H
L
H
L
H
L
TRUTH TABLE
OUTA
Off
Off
H
H
L
L
L
L
OUTB
Off
Off
L
L
H
H
L
L
DESCRIPTION
Sleep Mode
Standby
Forward, Fast Current-Decay Mode
Forward, Slow Current-Decay Mode
Reverse, Fast Current-Decay Mode
Reverse, Slow Current-Decay Mode
Brake, Fast Current-Decay Mode
Brake, No Current Control
115 Northeast Cutoff, Box 15036
2
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1995, 2000 Allegro MicroSystems, Inc.