The A3968 bidirectionally controls two DC motors. The device includes two full-bridges capable of continuous output currents of ±650 mA and operating voltages to 30 V. Motor winding current can be controlled by the internal fixed-frequency, pulse-width modulated (PWM), current-control circuitry. The peak load current limit is set by user selection of a reference voltage and current-sensing resistors.The fixed-frequency pulse duration is set by a user-selected external RC timing network. The capacitor in the RC timing network also determines a user-selectable blanking window that prevents false triggering of the PWM current-control circuitry during switching transitions.To reduce on-chip power dissipation, the full-bridge power outputs have been optimized for low saturation voltages. The sink drivers feature the Allegro® patented Satlington® output structure. The Satlington outputs combine the low voltage drop of a saturated transistor and the high peak current capability of a Darlington.For each bridge, the INPUTA and INPUTB terminals determine the load-current polarity by enabling the appropriate source and sink driver pair. When a logic low is applied to both INPUTs of a bridge, the braking function is enabled. In brake mode, both source drivers are turned off and both sink drivers are turned on, thereby dynamically braking the motor. When a logic high is applied to both INPUTs of a bridge, all output drivers are disabled.Special power-up sequencing is not required. Internal circuit protection includes thermal shutdown with hysteresis, ground-clamp and flyback diodes, and crossover-current protection.
Designed for pulse-width modulated (PWM) current control of dc motors, the A3959 is capable of output currents to ±3 A and operating voltages to 50 V. Internal fixed off-time PWM current-control timing circuitry can be adjusted via control inputs to operate in slow, fast, and mixed current-decay modes. PHASE and ENABLE input terminals are provided for use in controlling the speed and direction of a dc motor with externally applied PWM-control signals. Internal synchronous rectification control circuitry is provided to reduce power dissipation during PWM operation. Internal circuit protection includes thermal shutdown with hysteresis, under voltage monitoring of supply and charge pump, and crossover-current protection. Special power-up sequencing is not required.
±3 A, 50 V Output Rating
Low rDS(on) Outputs (270 milliohms, Typical)
Mixed, Fast, and Slow Current-Decay Modes
Synchronous Rectification for Low Power Dissipation
The Schematic is based on A4973 IC, Designed for bidirectional pulse width modulated (PWM) current control of inductive loads, the A4973 is capable of continuous output currents to ±1.5 A and operating voltages to 50 V. Internal fixed off-time PWM current-control circuitry can be used to regulate the maximum load current to a desired value. The peak load current limit is set by the user’s selection of an input reference voltage and external sensing resistor. The fixed off-time pulse duration is set by a user- selected external RC timing network. Internal circuit protection includes thermal shutdown with hysteresis, transient-suppression diodes, and crossover current protection. Special power-up sequencing is not required. With the ENABLE input held low, the PHASE input controls load current polarity by selecting the appropriate source and sink driver pair. The MODE input determines whether the PWM current-control circuitry operates in a slow current-decay mode (only the selected source driver switching) or in a fast current-decay mode (selected source and sink switching). A user-selectable blanking window prevents false triggering of the PWM current-control circuitry. With the ENABLE input held high, all output drivers are disabled. A sleep mode is provided to reduce power consumption.
Note : – For Higher Motor Supply (12-50V) Input, Omit U2 , in the case logic 5V supply required and possible Motor supply range 12-50V DC
Note : – Refer data sheet of IC A4973 for R1 and R2 Value
The circuit shown here are a DC Motor Speed and Direction Controller. Driver can handle DC Motor Load Up to 3Amp and DC supply 12V to 48V DC, The board is based on LMD18200 which is H-Bridge driver & 555 Timer IC generate PWM signal for speed control. Slide provided for direction Control. PWM duty cycle 10% 95%.
The LMD18201 is a 3A H-Bridge designed for motion control applications. The device is built using a multi- Shorted Load Protection technology process which combines bipolar and Internal Charge Pump with External Bootstrap CMOS control circuitry with DMOS power devices on Capability the same monolithic structure. The H-Bridge configuration is ideal for driving DC and stepper motors. The LMD18201 accommodates peak output currents up to 6A.
Motor Supply 12V 48V DC
Motor Load 3Amp 12V 48V DC
Logic Supply 5V DC
SW1 : Slide Switch To Change the Motor Direction CW/CCW
Switched Mode Controller for DC Motor Driver with Taco-Meter Using UC1637 & L298
The UC1637 is a pulse width modulator circuit intended to be used for a variety of PWM motor drive and amplifier applications requiring either uni-directional or bidirectional drive circuits. When used to replace conventional drivers, this circuit can increase efficiency and reduce component costs for many applications. All necessary circuitry is included to generate an analog error signal and modulate two bi-directional pulse train outputs in proportion to the error signal magnitude and polarity. This monolithic device contains a saw tooth oscillator, error amplifier, and two PWM comparators with ±100mA output stages as standard features. Protection circuitry includes under-voltage lockout, pulse-by-pulse current limiting, and a shutdown port with a 2.5V temperature compensated threshold.