Allegro A3973KB Dual full bridge protected motor driver Datasheet

Page 1 of 5
3976
ADVANCED DATASHEET - 02/19/99
(Subject to change without notice)
24 VCC
VBB 1
23 ENABLE2
ENABLE1 2
22 PHASE2
PHASE1 3
n/c 4
21 n/c
n/c 5
20 n/c
GROUND 6
GROUND 7
n/c 8
OUT1A 9
n/c 10
DUAL FULL BRIDGE
PROTECTED MOTOR DRIVER
A3976KLB
19 GROUND
18 GROUND
17 n/c
16 OUT2A
The A3976 is designed to drive both windings of a bipolar stepper
motor or bidirectionally control two DC Motors. Both H-Bridges are capable
of continuous output currents of up to +/- 500 mA and operating voltages to
30V. Free wheeling, substrate isolated diodes are included for output transient
suppression when switching motors or other inductive loads. For each bridge
the PHASE input controls load current polarity by selecting the appropriate
source and sink driver pair. The ENABLE input, when held high, enables the
respective output H-bridge. When both ENABLE pins are held low the device
will enter SLEEP mode and consume less than 100µA.
15 n/c
FAULT1 11
14 FAULT2
OUT1B 12
13 OUT2B
ABSOLUTE MAXIMUM RATINGS
at TA = +25°C
Operating Supply Voltage, VBB .................... 30 V
Non-Operating Supply Voltage..................... 35 V
Output Current, IOUT ............................±
±500 mA*
Logic Supply Voltage, VCC .......................... 7.0 V
Fault Output Voltage ................................... 7.0 V
Logic Input Voltage Range,
VIN.......................... -0.3 V to VCC + 0.3 V
Package Power Dissipation (TA = +25°C), PD
A3976KLB..................................2.2 W
A3976KB ....................................2.9 W
Operating Temperature Range,
TA ..............................-40°°C to +125°°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.
The 3976 is protected to ensure safe operation in harsh operating
environments and was designed specifically for automotive applications.
Protection circuitry will check for open or shorted load, motor lead short to
ground or supply, VBB overvoltage, VCC undervoltage, and thermal
shutdown. If any of these conditions are detected the outputs will be disabled
and fault information will be output to diagnostic pins FAULT1 and FAULT2.
The 3976 is supplied in a choice of two power packages, a 16-lead
plastic DIP with a copper batwing tab (suffix ‘B’), and a 24-lead plastic SOIC
with a copper batwing tab (suffix ‘LB’). In both cases, the power tab is at
ground potential and needs no electrical isolation.
FEATURES
n
n
n
n
n
n
n
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n
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30 V , ±500 mA Continuous Output Rating
35V Load Dump Survival
Output Short Circuit Protection
Coded Fault Diagnostic Outputs
Low Current Standby Mode
Open Load Monitor
Low Current Standby Mode
VBB Over Voltage Shutdown
Internal Thermal Shutdown Circuitry
Internal Low Parasitic Free Wheeling Diodes
Crossover Current Protection
PART NUMBER
PACKAGE
RØJA
RØJT
A3976KLB
24 Lead SOIC
56°°C/W
6°°C/W
A3973KB
16 Lead DIP
43°°C/W
6°°C/W
Page 2 of 5
3976 Dual Protected PWM Motor Driver
Functional Block Diagram
(one of two bridges shown)
VCC
Thermal
Shutdown
Over/Under
Voltage
Monitor
VBB
Short to Supply
Monitor
FAULT1
Diagnostic Logic
FAULT2
To Bridge 2
PHASE1
OUT1A
ENABLE1
CONTROL
LOGIC
PHASE2
OUT1B
ENABLE2
OUT2A
To Bridge 2
Input Pull Down
OUT2B
GROUND
Short to Ground
Monitor
Input Logic
PHASE
X
0
1
ENABLE
0
1
1
OUTA
Off
Low
High
OUTB
Off
High
Low
Fault Logic
Fault Condition
Thermal Shutdown
Short to Battery or Open Load
Short to Ground
Normal Operation
FAULT1
Low
Low
High
High
FAULT2
Low
High
Low
High
Page 3 of 5
3976 Dual Protected PWM Motor Driver
ELECTRICAL CHARACTERISTICS at TA = -40 °C to +125°C, VBB = 30 V, VCC = 5.0 V (Unless noted otherwise)
Limits
Characteristics
Symbol
Test Conditions
Min.
Typ.
Max.
Units
–
30
V
5.5
V
Output Drivers
Load Supply Voltage Range
VBB
Operating
6
Logic Supply Range
VCC
Operating
4.5
Output Current Limit
ICL
Outputs A or B = GROUND
0.7
1.1
–
A
Outputs A or B = VBB
0.7
1.1
–
A
VOUT = VBB
–
<1.0
50
µA
VOUT = 0 V
–
<1.0
-50
µA
Source Driver, IOUT = -350 mA
–
1.0
1.2
V
Source Driver, IOUT = -500 ma
–
1.2
1.3
Sink Driver, IOUT = +350 mA
–
0.2
0.4
V
Sink Driver, IOUT = +500 ma
–
0.4
0.6
V
IF = 500 mA (Sink / Ground Clamp)
–
1.2
1.5
V
IF = 500 mA (Source / Flyback)
–
1.55
2.0
V
ENABLE1 = ENABLE2 = High
–
7
10
mA
Sleep Mode ENABLE1 = ENABLE2 = Low
–
–
25
µA
ENABLE1 = ENABLE2 = High
–
45
50
MA
Sleep Mode, ENABLE1 = ENABLE2 = Low
–
–
75
µA
VIN(1)
0.7VCC
–
-
V
VIN(0)
–
–
.3VCC
V
Output Leakage Current
Output Saturation Voltage
Clamp Diode Forward Voltage
ICEX
VCE(SAT)
VF
(Flyback or Ground Clamp)
Control Logic
Motor Supply Current
IBB
(No Load)
Logic Supply Current
Logic Input Voltage
Logic Input Current
ICC
IIN(1)
VIN = 5 V
–
50
100
µA
IIN(0)
VIN = 0V
–
-1.0
-2.0
µA
Page 4 of 5
3976 Dual Protected PWM Motor Driver
ELECTRICAL CHARACTERISTICS at TA = -40°C +125°C, VBB = 30 V, VDD = 5.0 V (unless noted otherwise)
Limits
Characteristics
Symbol
Test Conditions
Min.
Typ.
Max.
Units
-
-
10
µA
–
0.8
V
Fault Circuitry
Fault Output Leakage
Fault Output Low
Fault Output Current
Output Open Load Current
Thermal Fault Temp.
Thermal Fault Hysteresis
IF-LEAK
VFL
VF = 5 Volts, No Faults
Fault Condition Asserted, IF=25 µA
VF = 5 Volts, ENABLE=3.5V
25
50
75
µA
VBB = 12 V
–
2
–
mA
TF
–
170
–
°C
TFHYS
–
10
–
°C
27
30
33
V
IF
I OUT-O.L.
OVLO Enable Threshold
Vbb rising
OVLO Hysteresis
1.5
UVLO Enable Threshold
Vcc falling
UVLO Hysteresis
V
3.5
4
4.5
V
–
400
–
mV
Timing
Open Fault to Reset Delay
trs
VBB = 12 V
–
–
25
µs
PHASE_X Delay to OPEN Fault
tof
VBB = 12 V
–
30
–
µs
PHASE_X Delay to S.C. Fault
tSC
VBB = 12 V
–
5
–
µs
ENABLE_X Delay to Fault
tof
VBB = 12 V
–
5
–
µs
Propagation Delay Times
tpd
IOUT = ±0.35A, 50%TO 90%
ENABLE ON TO SOURCE ON
–
0.3
µs
ENABLE OFF TO SOURCE OFF
–
0.4
µs
ENABLE ON TO SINK ON
–
0.3
µs
ENABLE OFF TO SINK OFF
–
0.2
µs
PHASE CHANGE TO SINK ON
–
4.0
µs
PHASE CHANGE TO SINK OFF
–
0.3
µs
PHASE CHANGE TO SOURCE ON
–
4.0
µs
PHASE CHANGE TO SOURCE OFF
–
0.4
µs
0.5
3.0
Cross Over Dead Time
tCODT
1KΩ (1k+1k) Load (VBB to OUT to GND)
6.0
µs
Page 5 of 5
3976 Dual Protected PWM Motor Driver
APPLICATION NOTES
Open Lead Protection. During normal PWM
operation diagnostic circuitry will look for a minimum
source current level after a bridge is signalled on.
Additionally, the diode flyback is monitored on the proper
output. The logic will signal a fault and disable the outputs if
it determines that the current is below the minimum level
AND no flyback is occurring. If the inductive load is too
large, the current would take too long to reach the minimal
level and a false open load would be reported. It is
recommended that the inductive load be less than 38mH.
Short Circuit Protection. Internal sense resistors in
series with VBB and ground will trip the fault circuitry if
greater than 1.1A is detected. To prevent false overcurrent
events due to reverse recovery spikes of the clamp diodes,
the current monitor is blanked for 5us after a high side is
signalled to turn on. If an additional input command follows
after the initial fault, the selected pair of drivers will pulse on
for the 5us blanking duration. The short circuit fault will
remember the input state where the fault occurred and will
wait for that particular logic state after the short has been
removed before normal operation is allowed to resume.
Thermal Protection. Circuitry turns OFF all drivers
when the junction temperature reaches 170°C typically. It is
intended only to protect the device from failures due to
excessive junction temperatures and has a hysteresis of
approximately 15°C.
Layout. The printed wiring board should use a heavy
ground plane. For optimum electrical and thermal
performance, the driver should be soldered directly onto the
board. The load supply pin, VBB, should be decoupled with
an electrolytic capacitor (> 47 µF is recommended) placed as
close to the device as possible.
Terminal List
Pin Name
VBB
ENABLE1
PHASE1
GROUND
OUT1A
FAULT1
OUT1B
OUT2B
FAULT2
OUT2A
PHASE2
ENABLE2
VCC
NC
Pin Description
Motor Supply Voltage
Control Logic – Bridge 1
Control Logic – Bridge 1
Power Ground Return
Bridge 1 Output
Diagnostic Output
Bridge 1 Output
Bridge 2 Output
Diagnostic Output
Bridge 2 Output
Control Logic – Bridge 2
Control Logic – Bridge 2
Logic Supply
No Connect
24 Lead SOIC
1
2
3
18,19,6,7
9
11
12
13
14
16
22
23
24
3,4,5,8,15,17,20,21
16 Lead DIP
1
2
3
4,5,12,13
6
7
8
9
10
11
14
15
16
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