DRV8251/A 48 V H-Bridge Motor Drivers

Texas Instruments' DRV8251 and DRV8251A are integrated motor drivers with an N-channel H-bridge, a charge pump, current regulation, protection circuitry, and current sense feedback (DRV8251A). The charge pump improves efficiency by supporting N-channel MOSFET half-bridges and 100% duty-cycle driving. 

The DRV8251A has internal current mirror architecture on the IPROPI pin to implement current sensing and regulation. This eliminates the need for a large power shunt resistor, saving board area and reducing system cost. The IPROPI current-sense output allows a microcontroller (MCU) to detect motor stalls or changes in the load conditions. The external voltage reference pin (VREF) determines the threshold of current regulation during start-up and stall events without interaction from an MCU.

The DRV8251 implements a current regulation feature by comparing the analog input VREF and the voltage across a current-sense shunt resistor on the ISEN pin. The ability to limit current can significantly reduce large currents during motor startup and stall conditions.

The low-power sleep mode achieves ultra-low quiescent current draw by shutting down most of the internal circuitry. Internal protection features include supply undervoltage lockout (UVLO), output overcurrent (OCP), and thermal shutdown (TSD). The DRV8251/A devices come in pin-to-pin, scalable R_DS(ON), and supply voltage options to support various loads and supply rails with minimal design changes.