UDN2917: Dual Full-Bridge PWM Motor Driver

Data Sheet
29319.22A
2917
GND
LOGIC SUPPLY
40
39
7
PWM 1
8
GND
38
9
37
1
10
36
11
35
12
34
13
VBB
33
14
2
31
16
30
PWM 2
EN 2
ENABLE 2 27
GND
RC 2 28
θ2
V REF 2 25
PHASE 2 26
I21 24
I20 23
LOAD SUPPLY 22
OUT 2B 21
SENSE 2 20
29
E2 19
17
OUT 2A 18
T
C
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, 33%, 67%, or 100% of
the maximum level. A PHASE input to each bridge determines load
current direction. Active-low ENABLE inputs control the four drivers in
each bridge.
U
D
Y
O L
32
15
GND
The UDN2917EB motor driver is 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 1.5 A.
VCC
ENABLE 1
RC1
41
PHASE 1
42
θ 1 43
EN1
I11
VREF 1
1
44
OUT 1B
I10
2
SENSE 1
3
4
OUT 1A
E1
6
5
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
Dwg. PP-021
Dwg. PP-021
N
R
O
P
E
C
D
E
N
U E
The UDN2917EB is supplied in a 44-lead power PLCC for surfacemount applications. Its batwing construction provides for maximum
package power dissipation in the smallest possible construction. The
UDN2917EB is provided for operation over an ambient temperature
range of -20°C to +85°C.
N ER
I
T F
ABSOLUTE MAXIMUM RATINGS
at TJ ≤ +150°C
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.
Motor Supply Voltage, VBB .................... 45 V
Output Current, IOUT (tw ≤ 20 µs) ..... ±1.75 A
(Continuous) ............................... ±1.5 A
Logic Supply Voltage, VCC .................... 7.0 V
Logic Input Voltage Range,
VIN ................................ -0.3 V to +7.0 V
Output Emitter Voltage, VE ................... 1.0 V
Package Power Dissipation,
PD ......................................... See Graph
Operating Temperature Range,
TA .................................. -20°C to +85°C
Storage Temperature Range,
TS ................................ -55°C to +150°C
E
N
R
O
R
C
S FO
I
D —
FEATURES
■ 1.5 A Continuous Output Current
■ 45 V Output Sustaining Voltage
■ Internal Clamp Diodes
■ Digital Control of Output Current
■ Internal Thermal Shutdown Circuitry
■ Similar to Dual PBL3770
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 +150°C.
Always order by complete part number: UDN2917EB .
2917
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
PWM CURRENT-CONTROL CIRCUITRY
VBB
CHANNEL 1
PIN NUMBERS
SHOWN.
22
OUT B
6
3
OUT A
V REF 44
5
20 kΩ
÷10
E
SENSE –
4
40 kΩ
RC
10 kΩ
I0 2
ONE
SHOT
+
RS
I1 1
41
SOURCE
DISABLE
RC
CC
RT
CT
TRUTH TABLE
12.5
T
R θJ
/W
°C
=6
ALLOWABLE PACKAGE POWER DISSIPATION IN WATTS
Dwg. EP-007-2A
10
Enable
Phase
OutA
OutB
L
L
H
H
L
X
H
L
Z
L
H
Z
X = Don’t care
Z = High impedance
7.5
5.0
R
2.5
θJA = 3
0°
C/W
0
25
50
75
100
TEMPERATURE IN °C
125
150
Dwg. GP-020B
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1991, 2004 Allegro MicroSystems, Inc.
2917
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
ELECTRICAL CHARACTERISTICS at TA = +25°C, VBB = 45 V, VCC = 5.0 V, VREF = 5.0 V (unless
otherwise noted).
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
10
—
45
V
VOUT = VBB
—
<1.0
50
µA
VOUT = 0
—
<-1.0
-50
µA
Output Drivers (OUTA or OUTB)
Motor Supply Range
VBB
Output Leakage Current
ICEX
Output Sustaining Voltage
VCE(sus)
IOUT = ±1.5 A, L = 3.5 mH
45
—
—
V
Output Saturation Voltage
VCE(SAT)
Sink Driver, IOUT = +1.0 A*
—
0.5
0.7
V
Sink Driver, IOUT = +1.5 A*
—
0.8
1.0
V
Source Driver, IOUT = -1.0 A*
—
1.8
1.9
V
Source Driver, IOUT = -1.5 A*
—
1.9
2.1
V
Clamp Diode Leakage Current
IR
VR = 45 V
—
<1.0
50
µA
Clamp Diode Forward Voltage
VF
IF = 1.5 A
—
1.6
2.0
V
Driver Supply Current
IBB(ON)
Both Bridges On, No Load
—
9.0
12
mA
IBB(OFF)
Both Bridges Off
—
4.0
6.0
mA
VIN(1)
All Inputs
2.4
—
—
V
VIN(0)
All Inputs
—
—
0.8
V
IIN(1)
VIN = 2.4 V
—
<1.0
20
µA
IIN(0)
VIN = 0.8 V
—
-3.0
-200
µA
Reference Voltage Range
VREF
Operating
1.5
—
7.5
V
Current Limit Threshold
(at trip point)
VREF /VSENSE
I0 = I1 = 0.8 V
9.5
10
10.5
—
I0 = 2.4 V, I1= 0.8 V
13.5
15
16.5
—
I0 = 0.8 V, I1 = 2.4 V
25.5
30
34.5
—
—
170
—
°C
Control Logic
Input Voltage
Input Current
Thermal Shutdown Temp.
TJ
Total Logic Supply Current
ICC(ON)
I0 = I1 = VEN = 0.8 V, No Load
—
90
105
mA
ICC(OFF)
I0 = I1 = 2.4 V, No Load
—
10
12
mA
Negative current is defined as coming out of (sourcing) the specified device pin.
Typical Data is for design information only.
* Pulse test (<10 ms).
www.allegromicro.com
2917
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
APPLICATIONS INFORMATION
PWM OUTPUT CURRENT WAVEFORM
PWM CURRENT CONTROL
The UDN2917EB dual bridge is 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 it is
sensed by the external sense resistor until the
sense voltage (VSENSE) reaches the level set
at the comparator’s input:
V PHASE
+
I OUT
0
–
I TRIP
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 µs. After turn-off, the
motor current will normally decay, 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 =
RTCT within the range of 20 kΩ to 100 kΩ and
200 pF to 500 pF.
td
t off
Dwg. WM-003-1A
LOAD CURRENT PATHS
V
BB
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.
Special circuitry has been included to
prevent runaway current control when the
fixed off time (toff) is set too short. This
circuitry prevents the source driver from being
re-enabled until the load current has decayed
to below the ITRIP level.
RS
BRIDGE ON
SOURCE OFF
ALL OFF
Dwg. EP-006-1
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
2917
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
CURRENT-CONTROL
TRUTH TABLE
Loads with high distributed capacitances may result in high turn-on
current peaks. This peak (appearing across RS) will attempt to trip the
comparator, resulting in erroneous current control or high-frequency
oscillations. An external RCCC low-pass filter may be needed to delay
the action of the comparator.
I0
I1
Output Current
L
L
VREF /10 RS = ITRIP
H
L
VREF /15 RS = 2/3 ITRIP
LOGIC CONTROL OF OUTPUT CURRENT
L
H
VREF /30 RS = 1/3 ITRIP
H
H
0
Two logic level inputs (I0 and I1) allow digital selection of the motor
winding current at 100%, 67%, 33%, 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. These logic level
inputs greatly enhance the implementation of µP-controlled drive
formats.
During half-step operations, the I0 and I1 inputs allow the µP to
control the motor at a constant torque between all positions in an eightstep 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.
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.
GENERAL
To avoid excessive voltage spikes on the LOAD SUPPLY pin
(VBB), a large-value capacitor (≥47 µF) should be connected from VBB
to ground as close as possible to the device. Under no circumstances
should the voltage at LOAD SUPPLY exceed 45 V.
The PHASE input to each bridge determines the direction motor
winding current flows. An internally generated deadtime (approximately 3 µs) prevents crossover currents that can occur when switching the PHASE input.
All four drivers in the bridge output can be turned off (VEN ≥ 2.4 V
or I0 = I1 ≥ 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. All logic inputs float high; the
ENABLE input must be tied low if it is not used.
Varying the reference voltage (VREF) provides continuous control
of the peak load current for micro-stepping applications, within the
specified limits for VREF.
Thermal protection circuitry turns off all drivers when the junction
temperature reaches +170°C. 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
re-enabled when the junction temperature cools to +145°C.
www.allegromicro.com
2917
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
UDN2917EB
Dimensions in Inches
(controlling dimensions)
18
28
29
17
0.032
0.026
0.319
0.291
0.695
0.685
0.021
0.013
0.656
0.650
0.319
0.291
0.050
INDEX AREA
BSC
39
7
40
0.020
44
1
2
6
0.656
0.650
MIN
0.695
0.685
0.180
0.165
Dwg. MA-005-44A in
Dimensions in Millimeters
(for reference only)
28
18
29
17
0.812
0.661
8.10
7.39
17.65
17.40
0.533
0.331
16.662
16.510
8.10
7.39
INDEX AREA
1.27
BSC
39
7
40
0.51
MIN
4.57
4.20
44
1
2
6
16.662
16.510
17.65
17.40
Dwg. MA-005-44A mm
NOTES: 1. MO-047AC except for terminal shoulder height.
2. Webbed lead frame. Leads 7-17 and 29-39 are internally one piece.
3. Lead spacing tolerance is non-cumulative.
4. Exact body and lead configuration at vendor’s option within limits shown.
5. Supplied in standard sticks/tubes of 27 devices or add “TR” to part number for tape and reel.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
2917
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
The products described here are manufactured under one or more
U.S. patents or U.S. patents pending.
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.
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.
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