|
|
PDF A3903 Data sheet ( Hoja de datos )
| Número de pieza | A3903 | |
| Descripción | Low Voltage DC Motor Driver | |
| Fabricantes | Allegro Micro Systems | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de A3903 (archivo pdf) en la parte inferior de esta página. Total 8 Páginas | ||
|
No Preview Available !
A3903
Low Voltage DC Motor Driver
Features and Benefits
▪ Constant voltage operation (adjustable)
▪ 500 mA output peak rating
▪ Low power standby mode
▪ Small 2 mm × 2 mm, 0.55 mm nominal height DFN
package
▪ Typical input voltage range of 3 to 5.5 V
▪ Adjustable constant voltage or PWM operation
▪ Less than 500 nA standby mode current
▪ –40 to 85 operating temperature range
Package: 8 Contact DFN (suffix EE)
Approximate Scale 1:1
Description
The A3903 is a low voltage bidirectional DC motor driver with
a typical input voltage range of 3 to 5.5 V and output currents up
to 500 mA. The unique output full-bridge incorporates source-
side linear operation to allow a constant voltage across the motor
coil. This regulated output minimizes motor voltage change due
to I × RDS(on) variation and battery voltage tolerance.
Logic input pins are provided to control the motor direction of
rotation, brake, and standby (< 500 nAsupply current) modes and
to allow optional PWM of the sink drivers. Internal protection
circuitry includes thermal shutdown, undervoltage lockout, and
crossover current (shoot-through) protection.
The A3903 is supplied in a 2 mm x 2 mm, 0.55 mm nominal
height, 8-lead DFN package, with exposed thermal pad (package
suffix EE). This small footprint package is lead (Pb) free, with
100% matte tin leadframe plating.
Applications include:
▪ Robotic actuators and pumps
▪ Portable printers/scanners
▪ Camera lens/shutter control
▪ Battery powered toys and games
▪ Low noise test instrumentation systems
Typical Application
+VBAT
CPU
VDD
IN1
IN2
VREF
A3903
OUTA
OUTB
VSET
GND
M
3903-DS, Rev. 2
1 page  
A3903
Low Voltage DC Motor Driver
Functional Description
Voltage Regulation The A3903 regulates the voltage
across the motor coil. The voltage across the OUTA
and OUTB terminal is sensed and compared to an
internal threshold voltage. The high-side switch will
be driven in linear mode to keep the applied voltage
maintained at the calculated level, as follows:
VOUT = 4 × VREF (R2 / [R1+R2]) ,
where VREF (VBG) is 1.285 V typical.
Then, for forward mode:
VOUT = VOUTA – VOUTB ,
and for reverse mode:
VOUT = VOUTB – VOUTA .
The alternative method is to provide a tightly regu-
lated voltage to the motor supply pin and run the
source and sink drivers as switches. The voltage drop
across these switches will vary linearly with tempera-
ture and current, therefore the voltage across the motor
coil also will vary. The A3903 will eliminate these
sources of error for a system where controlling the
motor voltage is the optimum means of control.
Thermal Shutdown The A3903 will disable the out-
puts if the junction temperature, TJ , reaches 165°C.
There is 15°C of hysteresis, so when the junction
temperature drops below 150°C, the device will begin
to operate normally.
Dropout Mode The source and sink drivers have a
total RDS(on) of approximately 1.2 Ω total. When the
motor supply voltage, VDD, drops too low compared
to the regulated value, the IC enters dropout mode. In
this case, the voltage across the motor coil will be:
VMOTOR = VDD – ILOAD (RDS(sink) + RDS(src))
Brake Mode When both inputs are high, the A3903
goes into high-side brake mode (turns on both source
drivers). There is no protection during braking, so care
must be taken to ensure that the peak current does not
exceed the absolute maximum current, IOUT.
Standby Mode To minimize battery drain, standby
mode will turn off all of the circuitry and draw typi-
cally less than 100 nA from the VDD line. There will
be a very short delay, approximately 2 μs, before
enabling the output drivers after release of standby
mode.
Power Dissipation. Power can be approximated
based on the below three components:
PD(src) = ILOAD (VDD –VREG) ,
PD(sink) = ILOAD × RDS(sink) , and
Pbias = VDD × IDD.
Control Logic Table
Settings
IN1 IN2 OUTA
0 0 Off
0 1 Low
1 0 VREG
1 1 High
OUTB
Off
VREG
Low
High
Resulting Mode
Standby
Reverse
Forward
Brake
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
5
5 Page | ||
| Páginas | Total 8 Páginas | |
| PDF Descargar | [ Datasheet A3903.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| A390 | SILICON RECTIFIER |  Powerex Power Semiconductors |
| A3901 | Dual Full Bridge Low Voltage Motor Driver |  Allegro |
| A3903 | Low Voltage DC Motor Driver | Allegro Micro Systems |
| A3904 | Low Voltage Voice Coil Motor Driver |  Allegro MicroSystems |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |