A3906
Low Voltage Stepper and Single/Dual DC Motor Driver
Features and Benefits
▪
2.5 to 9 V operation
▪
Internal PWM current limit control
▪
Synchronous rectification for reduced power dissipation
▪
Peak current output flag
▪
Undervoltage lockout
▪
Low R
DS(on)
outputs
▪
Small package
▪
Brake mode for DC motors
▪
Sleep function
▪
Crossover-current protection
▪
Thermal shutdown
Description
Designed for pulse width modulated (PWM) control of low
voltage stepper motors, and single and dual DC motors, the
A3906 is capable of output currents up to 1 A per channel and
operating voltages from 2.5 to 9 V.
The A3906 has an internal fixed off-time PWM timer that
sets a peak current based on the selection of a current sense
resistor. An overcurrent output flag is provided that notifies
the user when the current in the motor winding reaches the
peak current determined by the sense resistor. The fault output
does not affect driver operation.
The A3906 is provided in a 20-contact, 4 mm × 4 mm, 0.75 mm
nominal overall height QFN, with exposed pad for enhanced
thermal dissipation. It is lead (Pb) free, with 100% matte tin
leadframe plating.
Applications include the following:
▪
Digital still cameras (DSC)
▪
Cell phone cameras
▪
USB powered devices
▪
Battery powered devices
Approximate size
Package: 20-contact QFN (suffix ES)
Typical Applications
0.1
μF
CP1
CP2
CP3
0.1
μF
CP4
VCP
0.1
μF
SLEEP
VBB
10
μF
10 V
OUT1A
M
OUT1B
SENSE1
+5 V
0.1
μF
CP1
CP2
CP3
0.1
μF
CP4
VCP
0.1
μF
SLEEP
VBB
10
μF
10 V
OUT1A
OUT1B
SENSE1
M
OUT2A
FL1
FL2
GND
M
OUT2B
SENSE2
FL1
FL2
GND
OUT2A
OUT2B
SENSE2
A3906
IN1
IN2
IN3
+5 V
IN4
A3906
IN1
IN2
IN3
IN4
Dual DC motor application
3906-DS, Rev. 4
Stepper motor application
A3906
Selection Guide
Part Number
A3906SESTR-T
Low Voltage Stepper and Single/Dual DC Motor Driver
Packing
1500 pieces per 7-in. reel
Package
20-pin QFN with exposed thermal pad
Absolute Maximum Ratings
Characteristic
Load Supply Voltage
Logic Input Voltage Range
Sense Voltage
Output Current
Output Current in Paralleled
Operation
Operating Temperature Range
Junction Temperature
Storage Temperature Range
Symbol
V
BB
V
IN
V
SENSEx
I
OUT
I
OUT(par)
T
A
T
J(max)
T
stg
Continuous
Pulsed, t
w
< 1
μs
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.
Range S
Continuous
Peak, DC < 30%
Continuous
Peak, DC < 30%
Notes
Rating
9.6
–0.3 to 7
0.5
1
1
1.5
2
2.5
–20 to 85
150
–40 to 150
Units
V
V
V
V
A
A
A
A
°C
°C
°C
Thermal Characteristics
may require derating at maximum conditions, see application information
Characteristic
Package Thermal Resistance
Symbol
R
θJA
Test Conditions*
4-layer PCB based on JEDEC standard
Value Units
37
ºC/W
*Additional thermal information available on the Allegro website.
Terminal List Table
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
–
Name
CP2
GND
SLEEP
IN1
IN2
IN3
IN4
FL1
FL2
OUT2A
SENSE2
OUT2B
VBB
OUT1B
SENSE1
OUT1A
VCP
CP3
CP1
CP4
PAD
Function
Charge pump capacitor terminal 2
Ground
Sleep logic input, active low
Control input
Control input
Control input
Control input
Current limit flag, bridge 1
Current limit flag bridge 2
DMOS full-bridge 2, output A
Current sense resistor terminal, bridge 2
DMOS full-bridge 2, output B
Supply Voltage
DMOS full-bridge 1, output B
Current sense resistor terminal, bridge 1
DMOS full-bridge 1, output A
Reservoir capacitor terminal
Charge pump capacitor terminal 3
Charge pump capacitor terminal 1
Charge pump capacitor terminal 4
Exposed pad for enhanced thermal performance
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Pin-out Diagram
16 OUT1A
17 VCP
20 CP4
19 CP1
18 CP3
CP2
GND
SLEEP
IN1
IN2
1
2
3
4
5
OUT2A 10
6
7
8
9
PAD
15
14
13
12
11
SENSE1
OUT1B
VBB
OUT2B
SENSE2
IN3
IN4
FL1
FL2
2
A3906
Low Voltage Stepper and Single/Dual DC Motor Driver
Functional Block Diagram
0.1
μF
0.1
μF
VCP
0.1
μF
10
μF
10 V
VBB
Charge Pump
GND
Regulator
CP4
CP1
CP2
CP3
VCP
VBB
Sense2
+5 V +5 V
SLEEP
Sense1
OUT1A
OUT1B
Sense1
FL1
FL2
PWM Latch and
Blanking
Comparator
Bridge 2
PWM Latch and
Blanking
Comparator
Bridge 1
SENSE1
VCP
VBB
RS1
IN1
IN2
IN3
IN4
Sense2
Control Logic
OUT2A
OUT2B
SENSE2
RS2
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
3
A3906
Low Voltage Stepper and Single/Dual DC Motor Driver
ELECTRICAL CHARACTERISTICS
1,2
valid at T
A
= 25°C and V
BB
= 2.5 to 9 V, unless otherwise noted
Characteristics
Operating Voltage Range
VBB Supply Current
Symbol
V
BB
Test Conditions
I
OUT
= 0 mA, PWM = 50 kHz, Duty Cycle = 50%
Min.
2.5
–
–
–
–
–
–
–
160
–
–20
2.0
–
Typ.
–
5
3
150
0.52
0.78
0.62
0.93
200
–
–
–
–
<100
<–100
150
–
–
–
–
300
3
30
235
100
425
2.31
300
165
15
Max.
9
–
–
500
0.60
–
0.74
–
240
1
20
5.5
0.8
500
–500
–
0.4
–
200
1
–
3.9
–
350
200
650
2.45
400
–
–
Units
V
mA
mA
nA
Ω
Ω
Ω
Ω
mV
V
μA
V
V
nA
nA
mV
V
V
mV
μA
μs
μs
μs
ns
ns
ns
V
mV
°C
°C
I
BB
I
OUT
= 0 mA, outputs disabled, V
BB
= 9.6 V
Sleep mode, V
IN
< 0.4 V
Source driver, I
OUT
= 400 mA , V
BB
= 3 V, T
J
= 25°C
Source driver, I
OUT
= 400 mA , V
BB
= 3 V, T
J
= 85°C
Sink driver, I
OUT
= 400 mA, V
BB
= 3 V, T
J
= 25°C
Sink driver, I
OUT
= 400 mA, V
BB
= 3 V, T
J
= 85°C
FLx falling edge
I = 400 mA
Outputs, V
OUT
= 9 V
Output Resistance
R
DS(on)
Current Trip Sense Voltage
Clamp Diode Voltage
Output Leakage Current
Control Logic
Logic Input Voltage
Logic Input Current
Input Hysteresis
¯ ¯¯ ¯ ¯ Input
¯¯ ¯ ¯ ¯
SLEEP
Fault Output
Fault Output Leakage Current
Fault Output Timer
Blank Time
Fixed Off-Time
Propagation Delay Time
Protection Circuitry
Crossover Delay
VBB Undervoltage Lockout Threshold
VBB Undervoltage Lockout Hysteresis
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
1
For
2
Specifications
V
SENSE
V
f
I
DSS
V
IN(1)
V
IN(0)
I
IN(1)
I
IN(0)
V
INhys
V
SLEEP(0)
V
SLEEP(1)
V
FLx
I
FLx
t
FLx
t
BLANK
t
OFF
t
pd(on)
t
pd(off)
t
COD
V
BBUVLO
V
BBUVHYS
T
JTSD
T
JTSDHYS
V
IN
= 5.5 V
V
IN
= 0.8 V
–
–
–
–
2
Flag asserted, I
FLx
= 1 mA
V
FLx
= 5 V
Reset of PWM latch
–
–
–
2.1
–
Input high to source on, input low to source off
Input low to sink off, input high to sink on
100
50
200
V
BB
rising
2.2
200
–
–
input and output current specifications, negative current is defined as coming out of (sourcing) the specified device pin.
over the operating temperature range are assured by design and characterization.
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
4
A3906
Low Voltage Stepper and Single/Dual DC Motor Driver
Fault Timing Diagram
I
TRIP
I
LOAD
FLx
Fault Asserted
t
FLx
Fault Asserted
t
FLx
Fault Asserted
NOTE: Timer resets after each reset of the PWM latch.
Control Logic
DC Motor Operation
IN1
0
1
0
1
IN2
0
0
1
1
IN3
0
1
0
1
IN4
0
0
1
1
OUT1A
Off
High
Low
Low
OUT1B
Off
Low
High
Low
OUT2A
Off
High
Low
Low
OUT2B
Off
Low
High
Low
Function
Disabled
Forward
Reverse
Brake
Stepper Motor Operation
IN1
0
1
0
0
0
0
0
1
1
IN2
0
0
0
1
1
1
0
0
0
IN3
0
1
1
1
0
0
0
0
0
IN4
0
0
0
0
0
1
1
1
0
OUT1A
Off
High
Off
Low
Low
Low
Off
High
High
OUT1B
Off
Low
Off
High
High
High
Off
Low
Low
OUT2A
Off
High
High
High
Off
Low
Low
Low
Off
OUT2B
Off
Low
Low
Low
Off
High
High
High
Off
Function
Disabled
Full Step 1
–
Full Step 2
–
Full Step 3
–
Full Step 4
–
Disabled
½ Step 1
½ Step 2
½ Step 3
½ Step 4
½ Step 5
½ Step 6
½ Step 7
½ Step 8
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
5
微控制器 MCU
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
