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2919 DUAL FULL-BRIDGE MOTOR DRIVER
2919
The A2919SB and A2919SLB motor drivers are designed to drive both windings of a bipolar stepper motor or bidirectionally control two dc motors. Both bridges are capable of sustaining 45 V and include internal pulse-width modulation (PWM) control of the output current to 750 mA. The outputs have been optimized for a low output-saturation voltage drop (less than 1.8 V total source plus sink at 500 mA). For PWM current control, the maximum output current is determined by the user's selection of a reference voltage and sensing resistor. Two logic-level inputs select output current limits of 0%, 41%, 67%, or 100% of the maximum level. A PHASE input to each bridge determines load current direction. The bridges include both ground clamp and flyback diodes for protection against inductive transients. Internally generated delays prevent cross-over currents when switching current direction. Special power-up sequencing is not required. Thermal protection circuitry disables the outputs if the chip temperature exceeds safe operating limits. The A2919SB is supplied in a 24-pin dual in-line plastic batwing package with a copper lead-frame and heat sinkable tabs for improved power dissipation capabilities. The A2919SLB is supplied in a 24-lead surface-mountable SOIC. Their batwing construction provides for maximum package power dissipation in the smallest possible construction. The A2919SB/SLB are available for operation from -40C to +85C. To order, change the suffix from 'S-' to 'E-'. These devices are also available on special order for operation to +125C. For applications not requiring quarter-step operation, but desire lower detent or running current, the similar UDN2916B/EB/LB may be preferred.
DUAL FULL-BRIDGE PWM MOTOR DRIVER
A2919SB
OUT 1A OUT 2A E2 SENSE 2 OUT 2B GROUND GROUND I 02 I
12
Data Sheet 29319.21
1 2 3 4 5 6 7 8 2
VBB
24 23
LOAD SUPPLY E1 SENSE 1 OUT 1B I 01 GROUND GROUND I 11 PHASE 1 V REF 1 RC 1 LOGIC SUPPLY
1
22 21 20 19 18 17
PWM 1
9 9 10 11 12 2
1
16 15 14
PHASE 2 V REF 2 RC 2
PWM 2
V CC
13
Dwg. PP-005
ABSOLUTE MAXIMUM RATINGS at TJ 150C
Motor Supply Voltage, VBB ................... 45 V Output Current, IOUT (Peak, tw 20 s) ........................ 1.0 A (Continuous) .......................... 750 mA Logic Supply Voltage, VCC ................... 7.0 V Logic Input Voltage Range, VIN ............................... -0.3 V to +7.0 V Output Emitter Voltage, VE .................. 1.5 V Package Power Dissipation, PD ....................................... See Graph Operating Temperature Range, TA ................................. -20C to +85C Storage Temperature Range, TS ............................... -55C to +150C
Output current rating may be limited by duty cycle, ambient temperature, and heat sinking. Under any set of conditions, do not exceed the specified peak current rating or a junction temperature of +150C.
FEATURES
s s s s s s s 750 mA Continuous Output Current 45 V Output Sustaining Voltage Internal Clamp Diodes Internal PWM Current Control Low Output Saturation Voltage Internal Thermal Shutdown Circuitry Half- or Quarter-Step Operation of Bipolar Stepper Motors RJT 6.0C/W 6.0C/W
Always order by complete part number: Part Number Package RJA A2919SB 24-Pin DIP 40C/W A2919SLB 24-Lead SOIC 55C/W
2919 DUAL FULL-BRIDGE MOTOR DRIVER
A2919SLB
ALLOWABLE PACKAGE POWER DISSIPATION IN WATTS
5
RJT = 6.0C/W
I
02
1
PWM 2
24 23 22 2 21 20 19
VBB
LOAD SUPPLY OUT 2B SENSE 2 E2 OUT 2A GROUND GROUND OUT 1A E1 SENSE 1 OUT 1B
I 12 PHASE 2 V REF 2 RC 2 GROUND GROUND LOGIC SUPPLY RC 1 V REF 1 PHASE 1 I 11
2 3 4 5 6 7 8 9 9 V CC 2
4
3
SUFFIX 'B', R JA = 40C/W
2
18 17 16 1 15
1
SUFFIX 'LB', R JA = 55C/W
0 25 50 75 100 TEMPERATURE IN C 125 150
Dwg. GP-049A
10
PWM 1
11 12
1
14 13
TRUTH TABLE
I 01
PHASE
Dwg. PP-047
OUTA H L
OUTB L H
H L
PWM CURRENT-CONTROL CIRCUITRY
'B' PACKAGE, CHANNEL 1 PIN NUMBERS SHOWN. V
BB
24
OUT B
1 21
OUT A V REF 15 60 k /10 120 k 42 k I 0 20 I 1 17 RS
23 E
SENSE -
22
+
ONE SHOT
14 RC
SOURCE DISABLE
RC CC RT
CT
Dwg. EP-007-3
115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 W Copyright (c) 1994 Allegro MicroSystems, Inc.
2919 DUAL FULL-BRIDGE MOTOR DRIVER
ELECTRICAL CHARACTERISTICS at TA = +25C, TJ 150C, VBB = 45 V, VCC = 4.75 V to 5.25 V, VREF = 5.0 V (unless otherwise noted).
Limits Characteristic Output Drivers (OUTA or OUT B)
Motor Supply Range Output Leakage Current VBB ICEX Operating VOUT = V BB VOUT = 0 Output Sustaining Voltage Output Saturation Voltage VCE(sus) VCE(SAT) IOUT = 750 mA, L = 3.0 mH Sink Driver, IOUT = +500 mA Sink Driver, IOUT = +750 mA Source Driver, IOUT = -500 mA Source Driver, IOUT = -750 mA Clamp Diode Leakage Current Clamp Diode Forward Voltage Driver Supply Current IR VF IBB(ON) IBB(OFF) VR = 45 V IF = 750 mA Both Bridges ON, No Load Both Bridges OFF 10 -- -- 45 + VF -- -- -- -- -- -- -- -- -- < 1.0 <-1.0 -- 0.4 1.0 1.0 1.3 < 1.0 1.6 20 5.0 45 50 -50 -- 0.6 1.2 1.2 1.5 50 2.0 25 10 V A A V V V V V A V mA mA
Symbol
Test Conditions
Min.
Typ.
Max.
Units
Control Logic
Input Voltage VIN(1) VIN(0) Input Current IIN(1) All inputs All inputs VIN = 2.4 V VIN = 0.8 V Reference Voltage Range Current Limit Threshold (at trip point) VREF VREF / VSENSE I0 = I1 = 0.8 V, VREF = 1.0 V to 7.5 V I0 = 2.4 V, I1 = 0.8 V, VREF = 1.5 V to 7.5 V I0 = 0.8 V, I1 = 2.4 V, VREF = 1.5 V to 7.5 V Thermal Shutdown Temperature Total Logic Supply Current TJ ICC(ON) ICC(OFF) Total Reference Current IREF1 + IREF2 I0 = I1 = 0.8 V, No Load I0 = I1 = 2.4 V, No Load VREF1 = VREF2 = 7.5 V, I0 = I1 = 2.4 V -- -- -- 140 170 40 10 185 -- 50 12 250 C mA mA A 20.7 24.4 28.0 -- 2.4 -- -- -- 1.0 9.5 13.5 -- -- <1.0 - 3.0 -- 10 15 -- 0.8 20 -200 7.5 10.5 16.5 V V A A V -- --
2919 DUAL FULL-BRIDGE MOTOR DRIVER
APPLICATIONS INFORMATION
PWM CURRENT CONTROL
The A2919SB/SLB dual bridges are designed to drive both windings of a bipolar stepper motor. Output current is sensed and controlled independently in each bridge by an external sense resistor (RS), internal comparator, and monostable multivibrator. When the bridge is turned ON, current increases in the motor winding and flows through the external sense resistor until the sense voltage (VS) reaches the level set at the comparator's input: ITRIP = VREF/10 RS The comparator then triggers the monostable, which turns OFF the source driver of the bridge. The actual load current peak will be slightly higher than the trip point (especially for low-inductance loads) because of the internal logic and switching delays. This delay (td) is typically 2 s. After turn-off, the motor current decays, circulating through the ground-clamp diode and sink transistor. The source driver's OFF time (and therefore the magnitude of the current decrease) is determined by the monostable's external RC timing components, where toff = R TCT within the range of 20 k to 100 k and 100 pF to 1000 pF. When the source driver is re-enabled, the winding current (the sense voltage) is again allowed to rise to the comparator's threshold. This cycle repeats itself, maintaining the average motor winding current at the desired level. Loads with high distributed capacitances may cause current spikes capable of tripping the comparator, resulting in erroneous current control. An external RCCC time delay should be used to delay the action of the comparator. Depending on load type, many applications will not require these external components (SENSE connected to E).
td
PWM OUTPUT CURRENT WAVE FORM
V PHASE
+ I
OUT
0 -
I TRIP
t off
Dwg. WM-003-1A
LOAD CURRENT PATHS
V BB
RS
BRIDGE ON SOURCE OFF ALL OFF
Dwg. EP-006-1
115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
2919 DUAL FULL-BRIDGE MOTOR DRIVER
LOGIC CONTROL OF OUTPUT CURRENT
Two logic level inputs (l0 and I1) allow digital selection of the motor winding current at 100%, 67%, 41%, or 0% of the maximum level per the table. The 0% output current condition turns OFF all drivers in the bridge and can be used as an OUTPUT ENABLE function.
GENERAL
The PHASE input to each bridge determines the direction motor winding current flows. An internally generated deadtime (approximately 2 s) prevents crossover currents that can occur when switching the PHASE input. All four drivers in the bridge output can be turned OFF between steps (l0 = l1 2.4 V) resulting in a fast current decay through the internal output clamp and flyback diodes. The fast current decay is desirable in half-step and high-speed applications. The PHASE, l0, and I1 inputs float high. Varying the reference voltage (VREF) provides continuous control of the peak load current for micro-stepping applications. Thermal protection circuitry turns OFF all drivers when the junction temperature reaches +170C. It is only intended to protect the device from failures due to excessive junction temperature and should not imply that output short circuits are permitted. The output drivers are reenabled when the junction temperature cools to +145C. The A2919SB/SLB output drivers are optimized for low output saturation voltages--less than 1.8 V total (source plus sink) at 500 mA. Under normal operating conditions, when combined with the excellent thermal properties of the batwing package design, this allows continuous operation of both bridges simultaneously at 500 mA.
CURRENT-CONTROL TRUTH TABLE
l0 L H L H I1 L L H H Output Current VREF/10 RS = 100% ITRIP V REF/15 RS = 67% ITRIP VREF/24.4 RS = 41% ITRIP 0
These logic level inputs greatly enhance the implementation of P-controlled drive formats. During half-step operations, l0 and l1 allow the P to control the motor at a constant torque between all positions in an eight-step sequence. This is accomplished by digitally selecting 100% drive current when only one phase is ON and 67% drive current when two phases are ON. Logic highs on both l0 and l1 turn OFF all drivers to allow rapid current decay. During quarter-step operation, I0 and I1 allow the P to control the motor position in a sixteen-step sequence. This is accomplished by digitally selecting drive current as shown in the table (for one quadrant of operation). Logic highs on both I0 and I1 turn OFF all drivers to allow rapid current decay. The logic control inputs can also be used to select a reduced current level (and reduced power dissipation) for `hold' conditions and/or increased current (and available torque) for start-up conditions.
QUARTER-STEPPING CURRENT CONTROL
Phase 1 Current Level 100% 100% 67% 41% 0% Phase 2 Current Level 0% 41% 67% 100% 100%
2919 DUAL FULL-BRIDGE MOTOR DRIVER
TYPICAL APPLICATION
STEPPER MOTOR
V 1 2 RS 3 RC C 4
C
VBB
BB
24 RS 23 +
1 2
RC 22 CC 21 20 19 18 17 FROM P
5 6 7 8 FROM P 9 9 10 VREF 11 12 RT CT V CC 2
PWM 1
1 16 15 14 13 +5 V CT RT V
REF
PWM 2
Dwg. EP-008B
115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
2919 DUAL FULL-BRIDGE MOTOR DRIVER
A2919SB
Dimensions in Inches
(controlling dimensions)
24
NOTE 1
13
0.014 0.008
0.430 0.280 0.240
MAX
0.300
BSC
1
0.070 0.045
6
7 1.280 1.230
0.100
BSC
12
0.005
MIN
0.210
MAX
0.015
MIN
0.150 0.115 0.022 0.014
Dwg. MA-001-25A in
Dimensions in Millimeters
(for reference only)
24
NOTE 1
13
0.355 0.204
10.92 7.11 6.10
MAX
7.62
BSC
1
1.77 1.15
6
7 32.51 31.24
2.54
BSC
12
0.13
MIN
5.33
MAX
0.39
MIN
3.81 2.93 0.558 0.356
Dwg. MA-001-25A mm
NOTES: 1. Webbed lead frame. Leads 6, 7, 18, and 19 are internally one piece. 2. Lead thickness is measured at seating plane or below. 3. Lead spacing tolerance is non-cumulative. 4. Exact body and lead configuration at vendor's option within limits shown.
2919 DUAL FULL-BRIDGE MOTOR DRIVER
A2919SLB
Dimensions in Inches
(for reference only)
24 13
0.0125 0.0091
0.2992 0.2914
0.491 0.394 0.050 0.016
0.020 0.013
1
2
3
0.6141 0.5985
0.050
BSC NOTE 1 NOTE 3
0 TO 8
0.0926 0.1043 0.0040 MIN.
Dwg. MA-008-25 in
Dimensions in Millimeters
(controlling dimensions)
24 13
0.32 0.23
7.60 7.40
10.65 10.00 1.27 0.40
0.51 0.33
1
2
3
15.60 15.20
1.27
BSC NOTE 1 NOTE 3
0 TO 8
2.65 2.35 0.10 MIN.
Dwg. MA-008-25A mm
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 design of its products. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringements of patents or other rights of third parties which may result from its use.
NOTES: 1. Webbed lead frame. Leads 6, 7, 18, and 19 are internally one piece. 2. Lead spacing tolerance is non-cumulative. 3. Exact body and lead configuration at vendor's option within limits shown.
115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000

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