2927 [ALLEGRO]
DUAL FULL-BRIDGE PWM MOTOR DRIVER; 双路全桥式PWM电动机驱动器
| 型号： | 2927 |
| 厂家： | 
ALLEGRO MICROSYSTEMS |
| 描述： | DUAL FULL-BRIDGE PWM MOTOR DRIVER |
| 文件： | 总8页 (文件大小：80K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
2927
PRELIMINARY INFORMATION
(Subject to change without notice)
September 16, 1997
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
The A2927SEB 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 50 V and include internal pulse-width
modulation (PWM) control of the output current to 1.5 A.
GND
GND
7
8
39
38
37
36
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.
PWM 1
9
1
10
11
12
13
14
15
16
17
35
34
33
32
31
30
2
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.
PWM 2
GND
29 GND
The A2927SEB is supplied in a 44-lead power PLCC for surface-
mount applications. Its batwing construction provides for maximum
package power dissipation in the smallest possible construction.
Dwg. PP-021
ABSOLUTE MAXIMUM RATINGS
at TJ ≤ +150°C
FEATURES
Motor Supply Voltage, VBB ................... 50 V
Output Current, IOUT ......................... ±1.5 A
Logic Supply Voltage, VCC ................... 7.0 V
Logic Input Voltage Range,
■ 1.5 A Output Current
■ 50 V Output Sustaining Voltage
■ Internal Flyback Diodes
■ Digital Control of Output Current
■ Undervoltage Lockout
VIN ............................... -0.3 V to +7.0 V
Output Emitter Voltage, VE .................. 1.0 V
Package Power Dissipation,
■ Internal Thermal Shutdown Circuitry
PD ........................................ See Graph
Operating Temperature Range,
TA ................................. -20°C to +85°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 peak
current rating or a junction temperature of +150°C.
Always order by complete part number: A2927SEB .
2927
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
PWM CURRENT-CONTROL CIRCUITRY
V
CHANNEL 1
PIN NUMBERS
SHOWN.
BB
22
OUT
A
OUT
B
6
3
V
44
REF
5
E
20 kΩ
÷10
–
+
ONE
SHOT
SOURCE
DISABLE
SENSE
4
40 kΩ
R
10 kΩ
C
41 RC
2
1
I
0
1
C
R
C
S
R
C
T
T
I
Dwg. EP-007-4
TRUTH TABLE
12.5
10
Enable
Phase
OutA
OutB
R
= 6
θ
L
H
L
H
L
L
H
Z
JT
L
H
°
C/W
X
Z
X = Don’t care
Z = High impedance
7.5
5.0
2.5
0
R
= 35
θ
JA
°
C/W
25
50
75
100
125
150
TEMPERATURE IN °C
Dwg. GP-020-1
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1997 Allegro MicroSystems, Inc.
2927
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
ELECTRICAL CHARACTERISTICS at TA = +25°C, VBB = 50 V, VCC = 5.0 V, VREF = 5.0 V (unless
otherwise noted).
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
Output Drivers (OUTA or OUTB)
Motor Supply Range
VBB
ICEX
IOUT = ±1.5 A, L = 15 mH
10
—
—
—
—
—
—
—
—
—
—
<1.0
<-1.0
0.5
50
5.0
-5.0
0.7
0.9
1.9
2.0
2.0
9.0
4.0
V
µA
µA
V
Output Leakage Current
VOUT = VBB
VOUT = 0
Output Saturation Voltage
VCE(SAT
Sink Driver, IOUT = +1.0 A*
Sink Driver, IOUT = +1.5 A*
Source Driver, IOUT = -1.0 A*
Source Driver, IOUT = -1.5 A*
IF = 1.5 A
)
0.8
V
1.8
V
1.9
V
Flyback Diode Forward Volt.
Driver Supply Current
VF
1.6
V
IBB(ON)
IBB(OFF)
Both Bridges ON, No Load
Both Bridges OFF
6.5
mA
mA
4.0
Control Logic
Input Voltage
VIN(1)
VIN(0)
IIN(1)
All Inputs
2.4
—
—
—
—
0.8
V
V
All Inputs
Input Current
VIN = 2.4 V
—
<1.0
-3.0
—
20
µA
µA
V
IIN(0)
VIN = 0.8 V
—
-200
7.5
Reference Voltage Range
VREF
Operating
1.5
9.5
13.5
25.5
—
Current Limit Threshold
(at trip point)
VREF/VSENSE
I0 = I1 = 0.8 V
I0 = 2.4 V, I1= 0.8 V
I0 = 0.8 V, I1 = 2.4 V
10
10.5
16.5
34.5
—
—
—
—
°C
mA
mA
15
30
Thermal Shutdown Temp.
Total Logic Supply Current
TJ
170
90
ICC(ON)
ICC(OFF)
I0 = I1 = VEN = 0.8 V, No Load
I0 = I1 = 2.4 V, No Load
—
105
12
—
10
Negative current is defined as coming out of (sourcing) the specified device pin.
Typical Data is for design information only.
* Pulse test (<10 ms).
2927
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
APPLICATIONS INFORMATION
PWM OUTPUT CURRENT WAVEFORM
PWM CURRENT CONTROL:
The UDN2927EB dual bridge is designed
to drive both windings of a bipolar stepper
motor. Output current is sensed and con-
trolled independently in each bridge by an
external sense resistor (RS), internal com-
parator, and monostable multivibrator.
V
PHASE
+
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:
I
0
–
OUT
I
TRIP
ITRIP = VREF/10 RS
t
t
off
The comparator then triggers the mon-
ostable which turns OFF the source driver of
the bridge. The actual load current peak will
be slightly higher than the trip point (espe-
cially 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 external 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
d
Dwg. WM-003-1A
LOAD CURRENT PATHS
V
BB
external RC timing components, where toff
RTCT within the range of 20 kΩ to 100 kΩ
and 200 pF to 500 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.
BRIDGE ON
R
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.
S
SOURCE OFF
ALL OFF
Dwg. EP-006-14
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
2927
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
CURRENT-CONTROL
TRUTH TABLE
GENERAL:
Both bridges have internal flyback diodes (connected
from the outputs to VBB) for protection against inductive
transients. External ground-clamp diodes (connected
from the outputs to ground) are required; Schottky
ground-clamp diodes are recommended to minimize on-
chip power dissipation.
I0
I1
Output Current
L
L
VREF/10 RS = ITRIP
H
L
L
H
H
VREF/15 RS = 2/3 ITRIP
VREF/30 RS = 1/3 ITRIP
0
To avoid excessive voltage spikes on the LOAD
SUPPLY terminal (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 50 V. A low-value
(0.1 µF) ceramic capacitor at this terminal may be used
for high-frequency noise suppression.
H
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 errone-
ous current control or high-frequency oscillations. An
external RCCC low-pass filter may be needed to delay the
action of the comparator.
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.
LOGIC CONTROL OF OUTPUT CURRENT:
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-con-
trolled drive formats.
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 flyback and external ground-
clamp 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.
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 eight-step sequence. This is accom-
plished by digitally selecting 100% drive current when only
one phase is ON and 67% drive current when two phases
are ON.
Varying the reference voltage (VREF) provides continu-
ous 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 approximately
+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 reenabled when the junction tempera-
ture cools to approximately +160°C.
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.
2927
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
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
INDEX AREA
0.050
BSC
39
7
44
1
2
40
6
0.020
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
44
1
2
40
6
16.662
16.510
0.51
MIN
4.57
4.20
17.65
17.40
Dwg. MA-005-44A mm
NOTES: 1. Exact body and lead configuration at vendor’s option within limits shown.
2. Lead spacing tolerance is non-cumulative.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
2927
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
This page intentionally left blank
2927
DUAL FULL-BRIDGE
PWM MOTOR DRIVER
BRIDGE & HALF-BRIDGE DRIVERS
SELECTION GUIDE
IN ORDER OF 1) OUTPUT CURRENT AND 2) OUTPUT VOLTAGE
Features
Output Ratings *
Internal
Diodes
Internal
Protection
Part
Number †
mA
V
Description
Outputs
±650
30
30
Dual PWM Full Bridge
Dual PWM Full Bridge
X
X
Bipolar
Bipolar
X
X
3966
3968
±750
45
45
45
Dual PWM Full Bridge
Dual PWM Full Bridge
Dual PWM Full Bridge
X
X
X
Bipolar
Bipolar
Bipolar
X
X
X
2916
2919
6219
±800
±900
33
14
7.0
50
Dual PWM Full Bridge
X
Bipolar
DMOS
NMOS
Bipolar
X
X
X
X
3964
3-Ø Back-EMF Controller/Driver
3-Ø Back-EMF Controller/Driver
PWM Full Bridge
X
X
X
8902-A
8984
±1000
±1300
±1500
3953
45
45
50
50
Dual PWM Full Bridge
Dual PWM Full Bridge
PWM Microstepping Full Bridge
PWM Microstepping Full Bridge
X
X
X
X
Bipolar
Bipolar
Darlington/Satlington™
Darlington/Satlington™
X
X
X
X
2917
2918
3955
3957
±2000
45
50
50
50
3-Ø Brushless Controller/Driver
Dual Full Bridge
X
X
X
X
Darlington
Darlington
Darlington
Darlington
X
X
X
X
2936
2998
3951
3952
PWM Full-Bridge
PWM Full-Bridge
±3000
±3400
±4000
45
45
14
PWM Control
X
X
X
Darlington
Bipolar
–
X
X
2962
2961
8925
PWM Control
3-Ø Brushless Controller/Driver
DMOS
*
Current is maximum specified test condition, voltage is maximum rating. See specification for sustaining voltage limits or over-
current protection voltage limits.
†
Complete part number includes additional characters to indicate operating temperature range and package style.
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.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
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