ALLEGRO A3966

Data Sheet
29319.25A†
3966
DUAL FULL-BRIDGE PWM
MOTOR DRIVER
A3966SLB
OUT1A
16
OUT 2A
15
PHASE 2
14
ENABLE 2
13
GROUND
12
SENSE 2
11
OUT 2B
VCC
10
LOGIC
SUPPLY
RC
9
1
V
PHASE 1
2
ENABLE 1
3
GROUND
4
SENSE1
5
OUT 1B
6
LOAD
SUPPLY
7
REFERENCE
8
LOGIC
V BB
V
REF
BB
LOGIC
RC
Dwg. PP-066-1
ABSOLUTE MAXIMUM RATINGS
Load Supply Voltage, VBB ...................... 30 V
Output Current, IOUT (peak) ........... ±750 mA
(continuous) .............................. ±650 mA
Logic Supply Voltage, VCC .................... 7.0 V
Input Voltage, Vin ........ -0.3 V to VCC + 0.3 V
Sense Voltage, VS ................................ 1.0 V
Package Power Dissipation (TA = 25°C), PD
A3966SA ..................................... 2.08 W*
A3966SLB ................................... 1.87 W*
Operating Temperature Range,
TA ..................................... -20°C to +85°C
Junction Temperature,
TJ .................................................. +150°C
Storage Temperature Range,
TS ................................... -55°C to +150°C
Output current rating may be limited by duty cycle,
ambient temperature, and heat sinking. Under any set
of conditions, do not exceed the specified current rating
or a junction temperature of 150°C.
* Per SEMI G42-88 Specification, Thermal Test Board
Standardization for Measuring Junction-to-Ambient
Thermal Resistance of Semiconductor Packages.
The A3966SA and A3966SLB are designed to drive both windings of a
two-phase bipolar stepper motor. Each device includes two H-bridges
capable of continuous output currents of ±650 mA and operating voltages to
30 V. Motor winding current can be controlled by the internal fixed-frequency, pulse-width modulated (PWM), current-control circuitry. The peak
load current limit is set by the user’s selection of a reference voltage and
current-sensing resistors. Except for package style and pinout, the two
devices are identical.
The fixed-frequency pulse duration is set by a user-selected external
RC timing network. The capacitor in the RC timing network also determines
a user-selectable blanking window that prevents false triggering of the PWM
current-control circuitry during switching transitions.
To reduce on-chip power dissipation, the H-bridge power outputs have
been optimized for low saturation voltages. The sink drivers feature Allegro’s
patented Satlington™ output structure. The Satlington outputs combine the
low voltage drop of a saturated transistor and the high peak current capability
of a Darlington.
For each bridge, a PHASE input controls load-current polarity by
selecting the appropriate source and sink driver pair. For each bridge, an
ENABLE input, when held high, disables the output drivers. Special powerup sequencing is not required. Internal circuit protection includes thermal
shutdown with hysteresis, ground-clamp and flyback diodes, and crossovercurrent protection.
The A3966SA is supplied in a 16-pin dual in-line plastic package. The
A3966SLB is supplied in a 16-lead plastic SOIC with copper heat sink tabs.
The power tab is at ground potential and needs no electrical isolation.
FEATURES
■
■
■
■
■
■
■
■
±650 mA Continuous Output Current
30 V Output Voltage Rating
Internal Fixed-Frequency PWM Current Control
Satlington™ Sink Drivers
User-Selectable Blanking Window
Internal Ground-Clamp & Flyback Diodes
Internal Thermal-Shutdown Circuitry
Crossover-Current Protection and UVLO Protection
Always order by complete part number:
Part Number
Package
RθJA
RθJC
RθJT
A3966SA
16-pin DIP
60°C/W
38°C/W
—
A3966SLB
16-lead batwing SOIC
67°C/W
—
6°C/W
3966
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
LOAD
SUPPLY
+
OUT 2B
OUT 2A
LOGIC
SUPPLY
OUT 1B
OUT 1A
FUNCTIONAL BLOCK DIAGRAM
V CC
PHASE 2
PHASE 1
CONTROL LOGIC1
UVLO
& TSD
CONTROL LOGIC2
V BB
UVLO
& TSD
PWM LATCH 1
BLANKING
GATE 1
CURRENT-SENSE
COMPARATOR 1
R
SENSE 1
CURRENT-SENSE
COMPARATOR 2
SENSE 2
+
–
+
–
BLANKING
GATE 2
PWM LATCH 2
R
Q
SOURCE
ENABLE 2
ENABLE 2
SOURCE
ENABLE 1
ENABLE 1
Q
S
S
÷4
OSC
R1S
RC
RT
GROUND
R 2S
CT
REFERENCE
Dwg. FP-036-6
TRUTH TABLE
A3966SA
16
ENABLE 1
15
PHASE 1
14
OUT 1A
13
GROUND
RC
12
GROUND
V
11
OUT 2A
10
PHASE 2
9
ENABLE 2
1
OUT 1B
2
LOAD
SUPPLY
3
REFERENCE
4
V REF
RC
5
LOGIC
SUPPLY
6
OUT 2B
7
SENSE 2
8
LOGIC
SENSE 1
V BB
LOGIC
CC
PHASE
X
H
L
ENABLE
H
L
L
X = Irrelevant
Dwg. PP-066-2
2
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1998, 2000 Allegro MicroSystems, Inc.
OUTA
Off
H
L
OUTB
Off
L
H
3966
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
ELECTRICAL CHARACTERISTICS at TA = +25°C, VBB = 30 V, VCC = 4.75 V to 5.5 V, VREF = 2 V,
VS = 0 V, 56 kΩ & 680 pF RC to Ground (unless noted otherwise)
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
VCC
—
30
V
Output Drivers
Load Supply Voltage Range
VBB
Operating, IOUT = ±650 mA, L = 3 mH
Output Leakage Current
ICEX
VOUT = 30 V
—
<1.0
50
µA
VOUT = 0 V
—
<-1.0
-50
µA
Source Driver, IOUT = -400 mA
—
1.7
2.0
V
Source Driver, IOUT = -650 mA
—
1.8
2.1
V
Sink Driver, IOUT = +400 mA, VS = 0.5 V
—
0.3
0.5
V
Sink Driver, IOUT = +650 mA, VS = 0.5 V
—
0.4
1.3
V
IF = 400 mA
—
1.1
1.4
V
IF = 650 mA
—
1.4
1.6
V
IBB(ON)
VENABLE1 = VENABLE2 = 0.8 V
—
3.0
5.0
mA
IBB(OFF)
VENABLE1 = VENABLE2 = 2.4 V
—
<1.0
200
µA
4.75
—
5.50
V
Output Saturation Voltage
Clamp Diode Forward Voltage
Motor Supply Current
(No Load)
VCE(SAT)
VF
Control Logic
Logic Supply Voltage Range
VCC
Operating
Logic Input Voltage
VIN(1)
2.4
—
—
V
VIN(0)
—
—
0.8
V
IIN(1)
VIN = 2.4 V
—
<1.0
20
µA
IIN(0)
VIN = 0.8 V
—
<-20
-200
µA
Reference Input Volt. Range
VREF
Operating
0.1
–
2.0
V
Reference Input Current
IREF
-2.5
0
1.0
µA
Reference Divider Ratio
VREF/VTRIP
3.8
4.0
4.2
—
Logic Input Current
Current-Sense Comparator
Input Offset Voltage
VIO
VREF = 0 V
-6.0
0
6.0
mV
Current-Sense Comparator
Input Voltage Range
VS
Operating
-0.3
—
1.0
V
Sense-Current Offset
ISO
IS – IOUT, 50 mA ≤ IOUT ≤ 650 mA
12
18
24
mA
NOTES:1. Typical Data is for design information only.
2. Negative current is defined as coming out of (sourcing) the specified device terminal.
www.allegromicro.com
3
3966
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
ELECTRICAL CHARACTERISTICS at TA = +25°C, VBB = 30 V, VCC = 4.75 V to 5.5 V, VREF = 2 V,
VS = 0 V, 56 kΩ & 680 pF RC to Ground (unless noted otherwise) (cont.)
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
CT = 680 pF, RT = 56 kΩ
22.9
25.4
27.9
kHz
Comparator Trip to Source OFF
—
1.0
1.4
µs
Cycle Reset to Source ON
—
0.8
1.2
µs
Control Logic (continued)
PWM RC Frequency
PWM Propagation Delay Time
fosc
tPWM
Cross-Over Dead Time
tcodt
1 kΩ Load to 25 V
0.2
1.8
3.0
µs
Propagation Delay Times
tpd
IOUT = ±650 mA, 50% to 90%:
ENABLE ON to Source ON
ENABLE OFF to Source OFF
ENABLE ON to Sink ON
ENABLE OFF to Sink OFF
PHASE Change to Sink ON
PHASE Change to Sink OFF
PHASE Change to Source ON
PHASE Change to Source OFF
—
—
—
—
—
—
—
—
100
500
200
200
2200
200
2200
200
—
—
—
—
—
—
—
—
ns
ns
ns
ns
ns
ns
ns
ns
TJ
—
165
—
°C
∆TJ
—
15
—
°C
—
4.1
4.6
V
0.1
0.6
—
V
Thermal Shutdown Temp.
Thermal Shutdown Hysteresis
UVLO Enable Threshold
UVLO Hysteresis
Logic Supply Current
VT(UVLO)+
Increasing VCC
VT(UVLO)hys
ICC(ON)
VENABLE 1 = VENABLE 2 = 0.8 V
—
—
50
mA
ICC(OFF)
VENABLE 1 = VENABLE 2 = 2.4 V
—
—
9.0
mA
NOTES:1. Typical Data is for design information only.
2. Negative current is defined as coming out of (sourcing) the specified device terminal.
4
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3966
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
FUNCTIONAL DESCRIPTION
Internal PWM Current Control. The A3966SA and
A3966SLB dual H-bridges are designed to drive both
windings of a bipolar stepper motor. Load current can be
controlled in each motor winding by an internal fixedfrequency PWM control circuit. The current-control
circuitry works as follows: when the outputs of the Hbridge are turned on, current increases in the motor winding. The load current is sensed by the current-control
comparator via an external sense resistor (RS). Load
current continues to increase until it reaches the predetermined value, set by the selection of external currentsensing resistors and reference input voltage (VREF)
according to the equation:
ITRIP = IOUT + ISO = VREF/(4 RS)
where ISO is the sense-current error (typically 18 mA) due
to the base-drive current of the sink driver transistor.
At the trip point, the comparator resets the sourceenable latch, turning off the source driver of that H-bridge.
The source turn off of one H-bridge is independent of the
other H-bridge. Load inductance causes the current to
recirculate through the sink driver and ground-clamp
diode. The current decreases until the internal clock
oscillator sets the source-enable latches of both H-bridges,
turning on the source drivers of both bridges. Load current
increases again, and the cycle is repeated.
V PHASE
The range of recommended values for RT and CT are
20 kΩ to 100 kΩ and 470 pF to 1000 pF respectively.
Nominal values of 56 kΩ and 680 pF result in a clock
frequency of 25 kHz.
Current-Sense Comparator Blanking. When the
source driver is turned on, a current spike occurs due to
the reverse-recovery currents of the clamp diodes and
switching transients related to distributed capacitance in
the load. To prevent this current spike from erroneously
resetting the source enable latch, the current-control
comparator output is blanked for a short period of time
when the source driver is turned on. The blanking time is
set by the timing component CT according to the equation:
tblank = 1900 CT (µs).
A nominal CT value of 680 pF will give a blanking
time of 1.3 µs.
The current-control comparator is also blanked when
the H-bridge outputs are switched by the PHASE or
ENABLE inputs. This internally generated blank time is
approximately 1 µs.
V
BB
+
I OUT
The frequency of the internal clock oscillator is set by
the external timing components RTCT. The frequency can
be approximately calculated as:
fosc = 1/(RT CT + tblank)
where tblank is defined below.
BRIDGE
ON
BRIDGE ON
ALL
OFF
0
SOURCE OFF
–
BRIDGE
ON
I TRIP
ALL OFF
SOURCE
OFF
td
RTC T
t blank
INTERNAL
OSCILLATOR
Dwg. WM-003-2
www.allegromicro.com
RS
Dwg. EP-006-16
5
3966
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
FUNCTIONAL DESCRIPTION (continued)
Load Current Regulation. Due to internal logic and
switching delays (td), the actual load current peak will be
slightly higher than the ITRIP value. These delays, plus the
blanking time, limit the minimum value the current control
circuitry can regulate. To produce zero current in a
winding, the ENABLE terminal should be held high,
turning off all output drivers for that H-bridge.
Logic Inputs. A logic high on the PHASE input results
in current flowing from OUTA to OUTB of that H-bridge.
A logic low on the PHASE input results in current flowing
from OUTB to OUTA. An internally generated dead time
(tcodt) of approximately 1 µs prevents cross-over current
spikes that can occur when switching the PHASE input.
A logic high on the ENABLE input turns off all four
output drivers of that H-bridge. This results in a fast
current decay through the internal ground clamp and
flyback diodes. A logic low on the ENABLE input turns
on the selected source and sink driver of that H-bridge.
The ENABLE inputs can be pulse-width modulated for
applications that require a fast current-decay PWM. If
external current-sensing circuitry is used, the internal
current-control logic can be disabled by connecting the
RTCT terminal to ground.
The REFERENCE input voltage is typically set with a
resistor divider from VCC. This reference voltage is
internally divided down by 4 to set up the current-comparator trip-voltage threshold. The reference input voltage
range is 0 to 2 V.
Output Drivers. To minimize on-chip power dissipation,
the sink drivers incorporate a Satlington™ structure. The
Satlington output combines the low VCE(sat) features of a
saturated transistor and the high peak-current capability of
a Darlington (connected) transistor. A graph showing
typical output saturation voltages as a function of output
current is on the next page.
6
Miscellaneous Information. Thermal protection
circuitry turns off all output drivers should the junction
temperature reach +165 °C (typical). This is intended
only to protect the device from failures due to excessive
junction temperatures and should not imply that output
short circuits are permitted. Normal operation is resumed
when the junction temperature has decreased about 15 °C.
The A3966 current control employs a fixed-frequency, variable duty cycle PWM technique. As a result,
the current-control regulation may become unstable if the
duty cycle exceeds 50%.
To minimize current-sensing inaccuracies caused by
ground trace IR drops, each current-sensing resistor
should have a separate return to the ground terminal of
the device. For low-value sense resistors, the I•R drops
in the printed-wiring board can be significant and should
be taken into account. The use of sockets should be
avoided as their contact resistance can cause variations in
the effective value of RS.
The LOAD SUPPLY terminal, VBB, should be
decoupled with an electrolytic capacitor (47 µF recommended) placed as close to the device as physically
practical. To minimize the effect of system ground IR
drops on the logic and reference input signals, the system
ground should have a low-resistance return to the load
supply voltage.
The frequency of the clock oscillator will determine
the amount of ripple current. A lower frequency will
result in higher current ripple, but reduced heating in the
motor and driver IC due to a corresponding decrease in
hysteretic core losses and switching losses respectively.
A higher frequency will reduce ripple current, but will
increase switching losses and EMI.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3966
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
Typical output saturation
voltages showing Satlington™
sink-driver operation.
OUTPUT SATURATION VOLTAGE IN VOLTS
2.5
TA = +25°C
2.0
SOURCE DRIVER
1.5
1.0
0.5
SINK DRIVER
0
200
300
400
500
600
700
OUTPUT CURRENT IN MILLIAMPERES
Dwg. GP-064-1
TYPICAL APPLICATION
16
1
PHASE 1
2
ENABLE 1
3
4
V BB
LOGIC
LOGIC
15
PHASE 2
14
ENABLE 2
13
0.5 Ω
Allegro MicroSystems, Inc. reserves the right to make, from time to
time, such departures from the detail specifications as may be
required to permit improvements in the performance, reliability, or
manufacturability of its products. Before placing an order, the user is
cautioned to verify that the information being relied upon is current.
0.5 Ω
5
12
+5 V
VREF
+
47 µF
BB
VCC
10
RC
9
+5 V
680 pF
7
8
10 kΩ
11
V
56 kΩ
39 kΩ
6
+24 V
The products described here are manufactured under one or more
U.S. patents or U.S. patents pending.
Allegro products are not authorized for use as critical components
in life-support devices or systems without express written approval.
The information included herein is believed to be accurate and
reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringement of patents or other rights of
third parties which may result from its use.
Dwg. EP-047-4A
www.allegromicro.com
7
3966
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
THIS PAGE INTENTIONALLY LEFT BLANK
8
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3966
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
THIS PAGE INTENTIONALLY LEFT BLANK
www.allegromicro.com
9
3966
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
A3966SA
Dimensions in Inches
(controlling dimensions)
0.014
0.008
9
16
0.430
MAX
0.280
0.240
0.300
BSC
1
0.070
0.045
0.100
0.775
0.735
8
0.005
BSC
MIN
0.210
MAX
0.015
0.150
0.115
MIN
0.022
0.014
Dwg. MA-001-16A in
Dimensions in Millimeters
(for reference only)
0.355
0.204
9
16
10.92
MAX
7.11
6.10
7.62
BSC
1
1.77
1.15
2.54
19.68
18.67
8
BSC
0.13
MIN
5.33
MAX
0.39
3.81
2.93
MIN
0.558
0.356
Dwg. MA-001-16A mm
NOTES: 1. Exact body and lead configuration at vendor’s option within limits shown.
2. Lead spacing tolerance is non-cumulative
3. Lead thickness is measured at seating plane or below.
10
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
3966
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
A3966SLB
Dimensions in Inches
(for reference only)
16
9
0.0125
0.0091
0.419
0.394
0.2992
0.2914
0.050
0.016
0.020
0.013
1
2
0.050
3
0° TO 8°
BSC
0.4133
0.3977
0.0926
0.1043
0.0040 MIN.
Dwg. MA-008-16A in
Dimensions in Millimeters
(controlling dimensions)
16
9
0.32
0.23
10.65
10.00
7.60
7.40
1.27
0.40
0.51
0.33
1
2
1.27
3
10.50
10.10
BSC
0° TO 8°
2.65
2.35
0.10 MIN.
Dwg. MA-008-16A mm
NOTES: 1. Exact body and lead configuration at vendor’s option within limits shown.
2. Lead spacing tolerance is non-cumulative
3. Webbed lead frame. Leads 4 and 13 are internally one piece.
www.allegromicro.com
11
3966
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
MOTOR DRIVERS
Function
Output Ratings*
Part Number†
INTEGRATED CIRCUITS FOR BRUSHLESS DC MOTORS
3-Phase Power MOSFET Controller
—
28 V
3933
3-Phase Power MOSFET Controller
—
50 V
3932
3-Phase Power MOSFET Controller
—
50 V
7600
2-Phase Hall-Effect Sensor/Driver
400 mA
26 V
3626
Bidirectional 3-Phase Back-EMF Controller/Driver
±600 mA
14 V
8906
2-Phase Hall-Effect Sensor/Driver
900 mA
14 V
3625
3-Phase Back-EMF Controller/Driver
±900 mA
14 V
8902–A
3-Phase Controller/Drivers
±2.0 A
45 V
2936 & 2936-120
INTEGRATED BRIDGE DRIVERS FOR DC AND BIPOLAR STEPPER MOTORS
Dual Full Bridge with Protection & Diagnostics
±500 mA
30 V
3976
PWM Current-Controlled Dual Full Bridge
±650 mA
30 V
3966
PWM Current-Controlled Dual Full Bridge
±650 mA
30 V
3968
PWM Current-Controlled Dual Full Bridge
±750 mA
45 V
2916
PWM Current-Controlled Dual Full Bridge
±750 mA
45 V
2919
PWM Current-Controlled Dual Full Bridge
±750 mA
45 V
6219
PWM Current-Controlled Dual Full Bridge
±800 mA
33 V
3964
PWM Current-Controlled Full Bridge
±1.3 A
50 V
3953
PWM Current-Controlled Dual Full Bridge
±1.5 A
45 V
2917
PWM Current-Controlled Dual Full Bridge
±1.5 A
45 V
2918
PWM Current-Controlled Microstepping Full Bridge
±1.5 A
50 V
3955
PWM Current-Controlled Microstepping Full Bridge
±1.5 A
50 V
3957
PWM Current-Controlled Dual DMOS Full Bridge
±1.5 A
50 V
3972
Dual Full-Bridge Driver
±2.0 A
50 V
2998
PWM Current-Controlled Full Bridge
±2.0 A
50 V
3952
DMOS Full Bridge PWM Driver
±2.0 A
50 V
3958
Dual DMOS Full Bridge
±2.5 A
50 V
3971
UNIPOLAR STEPPER MOTOR & OTHER DRIVERS
Voice-Coil Motor Driver
±500 mA
6V
8932–A
Voice-Coil Motor Driver
±800 mA
16 V
8958
Unipolar Stepper-Motor Quad Drivers
1A
46 V
7024 & 7029
Unipolar Microstepper-Motor Quad Driver
1.2 A
46 V
7042
Unipolar Stepper-Motor Translator/Driver
1.25 A
50 V
5804
Unipolar Stepper-Motor Quad Driver
1.8 A
50 V
2540
Unipolar Stepper-Motor Quad Driver
1.8 A
50 V
2544
Unipolar Stepper-Motor Quad Driver
3A
46 V
7026
Unipolar Microstepper-Motor Quad Driver
3A
46 V
7044
* Current is maximum specified test condition, voltage is maximum rating. See specification for sustaining voltage limits
or over-current protection voltage limits. Negative current is defined as coming out of (sourcing) the output.
† Complete part number includes additional characters to indicate operating temperature range and package style.
Also, see 3175, 3177, 3235, and 3275 Hall-effect sensors for use with brushless dc motors.
12
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000