A3901. Dual Full Bridge Low Voltage Motor Driver

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Lester Campbell
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1 A39 Features and Benefits ow R DS(on) outputs Full- and half-stepping capability Small package Forward, reverse, and brake modes for DC motors Sleep mode with zero current drain PWM control up to 25 khz Crossover-current protection Thermal shutdown (TSD) Package: Contact DFN (suffix EJ) Description The A39 is a dual full-bridge motor driver, designed for low voltage portable applications involving bipolar stepper or brush DC motors. The outputs have been optimized for low voltage drop, with currents up to ±4 ma (±8 ma with outputs paralleled) and an operating voltage range of 2.5 to 5.5 V. The four inputs (IN to ) can control a bipolar stepper motor in full- or half-step mode, or DC motors in forward, reverse, or brake mode. The inputs can be PWMed for current or speed control at frequencies up to 25 khz. Internal protection circuitry includes thermal shut down (TSD) and crossover (shoot-through) protection. The A39 is supplied in a 3 mm x 3 mm x.75 mm nominal height, -lead DFN package, with exposed thermal pad (package EJ ). This small footprint package is lead (Pb) free, with % matte tin leadframe plating. Approximate Scale : +VBAT µf V Typical Application CPU IN A39 OUT M +VBAT µf V Figure. Typical stepper motor control +VBAT µf V CPU IN A39 OUT M M CPU IN A39 OUT M Figure 2. Typical dual DC motor control Figure 3. Typical single DC motor control (paralleled outputs) 39-DS, Rev. 3

2 A39 Selection Guide Part Number A39SEJTR-T Packing Tape and reel, 5 pieces/reel Absolute Maximum Ratings Parameter Symbol Conditions Min. Typ. Max. Units oad Supply Voltage V BB 7 V Output Current per Channel* I OUT 4 ma ogic Input Voltage Range V IN.3 6 V Junction Temperature T J 5 C Storage Temperature Range T stg 55 5 C Operating Temperature Range T A 2 85 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 current rating or a junction temperature of 5 C. 5 Northeast Cutoff Worcester, Massachusetts U.S.A ; 2

3 A39 Functional Block Diagram µf V BRIDGE TSD OUT IN Control ogic and Gate Drive BRIDGE2 PAD Terminal Diagram IN OUT PAD Number Name Description IN ogic input 2 ogic input 2 3 Ground terminal 4 ogic input 3 5 ogic input 4 6 Bridge2 output to load 7 Bridge2 output to load 8 oad supply terminal 9 Bridge output to load OUT Bridge output to load Pad Exposed pad for thermal dissipation; connect to externally 5 Northeast Cutoff Worcester, Massachusetts U.S.A ; 3

4 A39 4

5 A39 Motor Operation Truth Table INx OUT 2 Function Stepper Motor IN Full Stepping Half-Stepping Sleep Mode Sleep Mode H H Step Step H Step 2 H H Step 2 Step 3 H Step 4 H H Step 3 Step 5 H Step 6 H H Step 4 Step 7 H Step 8 DC Motor (Dual) IN or or Hi-Z (Sleep Mode)/Coast H H Forward H H Reverse Brake DC Motor (Single, Paralleled) IN and and Hi-Z (Sleep Mode)/Coast H H Forward H H Reverse Brake DC Motor (External PWM) IN or or H H Forward Fast Decay H H Reverse Fast Decay H H Forward H = logic low, V INx < V IN()(max) ; = logic high, V INx > V IN()(min) 2 H = voltage high, source driver on; = voltage low, sink driver on H Slow Decay Reverse Slow Decay 5 Northeast Cutoff Worcester, Massachusetts U.S.A ; 5

6 A39 Characteristic Performance Output On Resistance versus oad Supply Voltage I OUT = ma 4. Output On Resistance versus oad Supply Voltage I OUT = 3 ma Source Sink Total Source Sink Total R DS(on) (Ω) R DS(on) (Ω) V BB (V) V BB (V) Output On Resistance versus Output Current V BB = 3 V 3.5 Output On Resistance versus Output Current V BB = 5 V R DS(on) (Ω) Source Sink Total R DS(on) (Ω) Source Sink Total I OUT (ma) I OUT (ma) 5 Northeast Cutoff Worcester, Massachusetts U.S.A ; 6

7 A39 Functional Description Device Operation. The A39 is a dual full-bridge low voltage motor driver capable of operating one stepper motor or up to two DC motors. MOSFET output stages substantially reduce the voltage drop and the power dissipation of the outputs of the A39 compared to typical drivers with bipolar transistors. Internal circuit protection includes thermal shutdown with hysteresis, clamp diodes, and crossover current protection. The A39 is designed for portable applications with a power-off (Sleep mode) current of 5 na typical, and an operating voltage of 2.5 to 5.5 V. The A39 logic inputs are 3 to 5 V logic compatible. Output current can be regulated by pulse width modulating (PWM) the inputs. The full-bridge outputs can be paralleled for higher-current applications (see figure 6). In conditions where the logic supply voltage drops below 2.5 V, both the sink and the source R DS(on) will increase beyond the specified values. In extreme cases, no power will be delivered to the motor(s). However, the device will not be damaged. In stepping operation, the device can drive in either full- or half-step mode. The stepping mode is set by the signal pattern on the INx terminals, as shown in the stepping timing diagrams. External PWM. Pulse width modulating the inputs allows the output current to be regulated. Slow decay mode is achieved by holding one input high while PWMing the other input. Holding one input low and PWMing the other input results in fast decay. See the External PWM diagram. Sleep Mode. Pulling all inputs to.5 V or less, sends the A39 into Sleep mode, during which it draws 5 na typical. Thermal Shutdown. The A39 will disable the outputs if the junction temperature reaches 65 C. When thermal shutdown is entered, after the junction temperature drops 5 C, the outputs will be re-enabled. Brake Mode. When driving DC motors, the A39 will go into Brake mode (turn on both sink drivers) when all inputs, INx, are logic. There is no protection during braking, so care must be taken to ensure that the peak current during braking does not exceed the absolute maximum current. 5 Northeast Cutoff Worcester, Massachusetts U.S.A ; 7

8 A39 Application Information V BB IN TSD OUT CONTRO OGIC/ GATE DRIVE μf/ V Stepper Motor Figure 4a. Typical stepper motor control application IN IOUT-2 I-4 +V BB /R motor A V BB /R motor +V BB /R motor A V BB /R motor Figure 4b. Full step mode timing chart IOUT-2 I-4 IN +V BB /R motor A V BB /R motor +V BB /R motor A V BB /R motor Figure 4c. Half step mode timing chart 5 Northeast Cutoff Worcester, Massachusetts U.S.A ; 8

9 A39 V BB IN TSD OUT DC Motor CONTRO OGIC/ GATE DRIVE μf/ V DC Motor Figure 5. Typical dual DC motor control application. Either IN or can be used to drive OUT and. Either or can be used to drive and. V BB IN TSD OUT DC Motor CONTRO OGIC/ GATE DRIVE μf V Figure 6. Typical single DC motor control (paralleled outputs) 5 Northeast Cutoff Worcester, Massachusetts U.S.A ; 9

10 A39 IN/3 /4 +V BB /R motor +(V BB V BEMF )/R motor IOUT-2/3-4 A (V BB V BEMF )/R motor V BB /R motor Forward Brake Reverse Coast Figure 7. Typical dual DC motor control application IN/3 /4 +I REG IOUT-2/3-4 A I REG Forward/ Fast Decay Reverse/ Fast Decay Forward/ Slow Decay Reverse/ Slow Decay Figure 8. External PWM current control in fast and slow decay modes 5 Northeast Cutoff Worcester, Massachusetts U.S.A ;

11 A39 Package EJ, -contact DFN A 2 D X.8 C C 2.38 PCB ayout Reference View.4 2 B.65 A All dimensions nominal, not for tooling use (reference JEDEC MO-229WEED) Dimensions in millimeters Exact case and lead configuration at supplier discretion within limits shown Terminal # mark area B Exposed thermal pad (reference only, terminal # identifier appearance at supplier discretion) 2.38 C Reference land pattern layout (reference IPC735 SON5P3X3X8-WEED3M); All pads a minimum of.2 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 JESD5-5) D Coplanarity includes exposed thermal pad and terminals Copyright 25,27, The products described here are manufactured under one or more U.S. patents or U.S. patents pending. reserves the right to make, from time to time, such de par tures from the detail spec i fi ca tions as may be required to permit improvements in the per for mance, 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 in for ma tion in clud ed herein is believed to be ac cu rate and reliable. How ev er, assumes no responsibility for its use; nor for any in fringe ment of patents or other rights of third parties which may result from its use. For the latest version of this document, visit our website: 5 Northeast Cutoff Worcester, Massachusetts U.S.A ;

A3909. Dual Full Bridge Motor Driver. Description. Features and Benefits. Packages: Functional Block Diagram

A3909. Dual Full Bridge Motor Driver. Description. Features and Benefits. Packages: Functional Block Diagram Features and Benefits Low R DS(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.8