Design of Octal Half-Bridge Motor Driver with Serial Input Control

This paper presents an 8-channel, half-bridge DMOS output driver controlled by Serial Peripheral Interface (SPI). The driver has 8-channel outputs, with up to six simultaneous outputs. By changing the output load and adjusting the SPI setting, full-bridge output or half-bridge output can be selected. And the serial interface clock frequency is up to 5MHz. Moreover, the driver equips with Short Circuit Protection (SCP), Under Voltage Protection (UVP), and thermal shutdown, which can timely alarm and protect the circuit in case of abnormal working conditions. The Driver is designed in DongBu HiTek (DBH) 0.18 um BCD process with the 5V and 55V Dual power supply voltage. The operating input range of the driver is between 9 to 55V, and the gate voltage of output MOSFET pair is increased through high-voltage charge pump technology, resulting in an output voltage of up to 55V. At a working voltage of 55V, the simulation results show that the on-state resistance of the bridge arm is less than 2 ohms, the start-up time is 173.8us, the working current is 0.8A, and the peak current can reach 1.3A. It can be applied to automotive and industrial loads as well as DC motors.