ALLEGRO A3909

A3909
Dual Full Bridge Motor Driver
Description
Features and Benefits
• Low RDS(on) outputs
• Drives two DC motors or single stepper motor
• Low power standby (Sleep) mode with zero current drain
• Thermal shutdown protection
• Parallel operation option for 1.8 A, single DC motor
• Overcurrent protection:
▫ Output to supply short
▫ Output to GND short
▫ Output load short
The A3909 is a dual full bridge motor driver, designed for
12 V medium power applications. The outputs are rated for
operation through a power supply range of 4 to 18 V, and
capable of up to 1 A per phase.
Paralleling the outputs is possible for higher amperage single
DC motor applications.
The four inputs (IN1 to IN4) can control DC motors in forward,
reverse, brake, and coast modes, or a bipolar stepper motor in
full- and half-step modes.
The A3909 is supplied in a 10-pin MSOP package with exposed
thermal pad (suffix LY) and a 10-pin SSOP (suffix LN) for
wave solder applications. Both packages are lead (Pb) free
with 100% matte-tin leadframe plating.
Packages:
10-pin MSOP
with exposed thermal pad
(LY package)
10-pin SSOP
(LN package)
Not to scale
Functional Block Diagram
VBB
IN1
Control
Logic
TSD
UVLO
OCP
Disable
Load Supply
VBB
OUT1
OUT1
OUT2
OUT2
GND
GND
Load Supply
VBB
IN2
VBB
IN3
Control
Logic
TSD
UVLO
OCP
Disable
OUT3
OUT3
OUT4
OUT4
VBB
IN4
GND
PAD
LY package
A3909-DS
Configuration
for driving
2 DC motors
Configuration
for parallel operation
at 1.8 A
A3909
Dual Full Bridge Motor Driver
Selection Guide
Part Number
Package
Packing
A3909GLNx-T*
10-pin SSOP
3000 pieces per 13-in. reel
A3909GLYTR-T
10-pin MSOP with
exposed thermal pad
4000 pieces per 13-in. reel
*Contact Allegro Sales for availability of this package option.
Absolute Maximum Ratings*
Rating
Unit
Supply Voltage
Characteristic
Symbol
VBB
Notes
18
V
Logic Input Voltage Range
VIN
–0.3 to 6
V
Output Current
IOUT
1
V
Output Voltage
VOUT
–0.3 to VBB + 1
V
Operating Ambient Temperature
TA
–40 to 105
ºC
Maximum Junction Temperature
TJ(max)
150
ºC
Tstg
–55 to 150
ºC
Storage Temperature
G temperature range
Thermal Characteristics may require derating at maximum conditions, see application information
Characteristic
Package Thermal Resistance
Symbol
RθJA
Value
Unit
LN package (estimated), on 1-layer PCB with copper limited
to pin area
Test Conditions*
130
ºC/W
LY package, on 2-layer PCB with 2.260 in.2 of copper area
each side
48
ºC/W
*Additional thermal information available on the Allegro website.
Terminal List Table
Number
Name
1
IN1
Logic input
2
IN2
Logic input
3
VBB
Input supply
4
IN3
Logic input
7 OUT3
5
IN4
Logic input
6 OUT4
6
OUT4
Motor terminal
7
OUT3
Motor terminal
8
GND
Ground
9
OUT2
Motor terminal
10
OUT1
Motor terminal
–
PAD
Pin-out Diagram
10 OUT1
IN1 1
IN2 2
VBB 3
IN3 4
IN4 5
PAD
(LY
package)
9 OUT2
8 GND
LN and LY packages
Function
(LY package) Exposed thermal pad
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
2
A3909
Dual Full Bridge Motor Driver
ELECTRICAL CHARACTERISTICS* Valid at TA = 25°C; unless otherwise specified
Characteristic
Symbol
VBB Voltage Range
VBB
VBB Supply Current
IBB
Total Driver On-Resistance (Sink +
Source)
RDS(on)tot
Test Conditions
Min.
Typ.
Max.
Unit
4
–
18
V
–
4
8
mA
Standby Mode
–
<1
10
μA
I = 1 A, TJ = 25°C, VBB = 12 V
–
1.6
2
Ω
I = 1 A, TJ = 25°C, VBB = 4 V
–
2.7
3.5
Ω
Source Driver On-Resistance
RDS(on)src
I = 1 A, TJ = 25°C, VBB = 12 V
–
1.12
–
Ω
Sink Driver On-Resistance
RDS(on)snk
I = 1 A, TJ = 25°C, VBB = 12 V
–
0.48
–
Ω
Input Logic Low Level
VIL(Standby) All inputs low
–
–
0.4
V
Input Logic Low Level
VIL
–
–
0.8
V
Input Logic High Level
VIH
2
–
–
V
100
300
500
mV
–
100
150
μA
–
3.6
3.95
V
100
300
500
mV
Input Hysteresis
Logic Input Current
VHYS
IIN
VBB UVLO
VBBUVLO
VBB UVLO Hysteresis
VBBHYS
Standby Timer
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
tSTB
VIN = 5 V (Pull down = 50 kΩ)
VBB rising
–
1
1.5
ms
TJTSD
IN1 = IN2 = IN3 = IN4 < VIL(Standby)
Temperature increasing
150
165
180
°C
ΔTJ
Recovery = TJTSD – ΔTJ
–
20
–
°C
*Specified limits are tested at a single temperature and assured through operating temperature range by design and characterization.
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
3
A3909
Dual Full Bridge Motor Driver
Motor Operation Truth Table
Stepper Motor
IN1
IN2
IN3
IN4
OUT1
OUT2
OUT3
OUT4
Function
0
0
0
0
Off
Off
Off
Off
Sleep Mode
Sleep Mode
1
0
1
0
H
L
H
L
Step 1
Step 1
0
0
1
0
Off
Off
H
L
–
Step 2
0
1
1
0
L
H
H
L
Step 2
Step 3
0
1
0
0
L
H
Off
Off
–
Step 4
0
1
0
1
L
H
L
H
Step 3
Step 5
0
0
0
1
Off
Off
L
H
–
Step 6
1
0
0
1
H
L
L
H
Step 4
Step 7
1
0
0
0
H
L
Off
Off
–
Step 8
DC Motors (Dual)
IN1 or IN3
IN2 or IN4
OUT1
OUT2
OUT3
OUT4
Function
0
0
Off
Off
Off
Off
High Impedance
(Sleep Mode) / Coast
1
0
H
L
H
L
Forward
0
1
L
H
L
H
Reverse
1
1
L
L
L
L
Brake
IN2 or IN4
OUT1
OUT2
OUT3
OUT4
Function
Off
High Impedance
(Sleep Mode) / Coast
DC Motor (Single, Paralleled)
IN1 or IN3
0
0
Off
Off
Off
1
0
0
1
H
L
H
L
Forward
L
H
L
H
Reverse
1
1
L
L
L
L
Brake
IN1 or IN3
IN2 or IN4
OUT1
OUT2
OUT3
OUT4
Function
1
0
H
L
H
L
Forward
0
0
Off
Off
Off
Off
Fast Decay
0
1
L
H
L
H
Reverse
0
0
Off
Off
Off
Off
Fast Decay
1
0
H
L
H
L
Forward
1
1
L
L
L
L
Slow Decay
0
1
L
H
L
H
Reverse
1
1
L
L
L
L
Slow Decay
DC Motor (External PWM)
NOTE: 0 = logic low with VINx < VIN(0)(max), 1 = logic high with VINx > VIN(1)(min), H = voltage high, source driver on, L = voltage low, sink driver on
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
4
A3909
Dual Full Bridge Motor Driver
Functional Description
Device Operation
The 3909 is designed to operate two DC motors or a single
stepper motor. The outputs are PMOS source drivers combined
with low RDS(on) DMOS sink drivers.
turned on. If the current exceeds 1.8 A for longer than 2 μs, then
a fault condition is asserted. The sink driver utilizes a drain-tosource voltage monitor. If the voltage exceeds 2 V for longer than
2 μs, the fault condition is asserted.
Protection circuitry includes internal thermal shutdown, protection against shorted loads, and against outputs shorted to GND
or supply. Undervoltage lockout prevents damage by keeping the
outputs off until the driver has enough voltage to operate normally.
When a fault occurs, the IC immediately disables both sides of
the full bridge where the fault occurred. The full bridge input
commands will be ignored for a 2 ms period before being allowed
to retry. Each channel has independent overcurrent protection.
A low power standby (Sleep) mode is activated when all inputs
are low for longer than 1 ms. Sleep mode disables all of the circuitry making the IC ideal for battery operated applications.
Overcurrent Protection (OCP)
The A3909 is protected against accidental shorts or motor outputs
to ground and supply, as well as a shorted load condition. For
the source drivers, the current is monitored after the MOSFET is
During OCP events, the absolute ratings may be exceeded for a
short period of time before the outputs are disabled.
Thermal Shutdown
If the die temperature increases to TJTSD , then all outputs are disabled until the internal temperature falls below a hysteresis level,
TTSDHYS, of 20°C. Internal UVLO is detected on VBB to prevent
output drivers from turning on when below the UVLO threshold.
DC Motor Timing Diagram
tSTANDBY
IN1
IN2
OUT1
OUT2
Current (12)
2
3
4
1) Low power standby (Sleep) mode (IBB = 0)
2) On, reverse – 100% duty cycle
3) On, forward – 100% duty cycle
4) Slow decay PWM
5
6
7
5) Fast decay PWM
6) Coast
7) Low power standby (Sleep) mode
after tSTANBY (IBB = 0)
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
5
A3909
Dual Full Bridge Motor Driver
Stepper Motor Timing Diagram
tSTANDBY
IN1
IN2
OUT1
OUT2
Current (12)
2
3
4
5
6
7
IN1
IN2
IN3
IN4
Current (12)
Current (34)
1
2
3
4
1
2
3
1
3
I (1/3)
3
4
Full Step
5
6
7
8
1
I (2/4)
I (2/4)
2
4
2
4
5
1
8
6
I (1/3)
7
Half Step
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
6
A3909
Dual Full Bridge Motor Driver
Application Information
1
IN1
A3909
10
OUT1
System
Controller
2
Load
Supply
3
4
5
IN2
PAD
(LY package)
9
OUT2
VBB
GND
IN3
OUT3
IN4
OUT4
8
DC Motor
7
6
Configuration for parallel operation with 1.8 A output current capability
LN package board
LY package board via layout for thermal dissipation
VBB
IN1
IN4
6.5 V
50 kΩ
GND
VBB
IN2
IN3
21 V
50 kΩ
OUT1
OUT2
OUT3
OUT4
VBB
21V
Input Output Pin Structures
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
7
A3909
Dual Full Bridge Motor Driver
Package LN, 10-Pin SSOP
4.90 ±0.20
0° to 8°
0.65
1.00
10
10
0.21 ±0.04
3.90 ±0.10
2.25
6.00 ±0.20
4.95
A
1.05 (REF)
1
1.27
0.40
2
2
1
Branded Face
C
PCB Layout Reference View
1.55 ±0.20
0.45
0.30
1.00
BSC
0.25
0.10
NNNNNNN
YYWW
LLLL
1
For Reference Only; not for tooling use
Dimensions in millimeters
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
A Terminal #1 mark area
B Branding scale and appearance at supplier discretion
C Reference land pattern layout. All pads a minimum of 0.20 mm from all
adjacent pads; adjust as necessary to meet application process
requirements and PCB layout tolerances; when mounting on a multilayer
PCB, thermal vias near the pin lands can improve thermal dissipation
(reference EIA/JEDEC Standard JESD51-7)
B Standard Branding Reference View
N = Device part number
= Supplier emblem
Y = Last two digits of year of manufacture
W = Week of manufacture
L = Lot number
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
8
A3909
Dual Full Bridge Motor Driver
Package LY, 10-Pin MSOP
With Exposed Thermal Pad
3.00 ±0.10
0° to 6°
10
0.15 ±0.05
3.00 ±0.10
0.30
0.50
10
1.65
4.88 ±0.20
1.73
4.60
A
0.53 ±0.10
1
2
1
2
0.25
1
1.98
1
Seating Plane
Gauge Plane
2
1.98 MIN
C
B
For Reference Only; not for tooling use (reference JEDEC MO-187BA-T)
Dimensions in millimeters
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
1.73
A Terminal #1 mark area
B Exposed thermal pad (bottom surface)
10
0.86 ±0.05
C Reference land pattern layout (reference IPC7351 SOP50P490X110-11M)
All pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary
to meet application process requirements and PCB layout tolerances; when
mounting on a multilayer PCB, thermal vias at the exposed thermal pad land
can improve thermal dissipation (reference EIA/JEDEC Standard JESD51-5)
SEATING
PLANE
0.27
0.18
0.50
REF
0.05
0.15
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
9
A3909
Dual Full Bridge Motor Driver
Copyright ©2013, Allegro MicroSystems, LLC
Allegro MicroSystems, LLC 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’s products are not to be used in life support devices or systems, if a failure of an Allegro product can reasonably be expected to cause the
failure of that life support device or system, or to affect the safety or effectiveness of that device or system.
The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, LLC assumes no responsibility for its
use; nor for any infringement of patents or other rights of third parties which may result from its use.
For the latest version of this document, visit our website:
www.allegromicro.com
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
10