| 摘要 |
A motor driver having over current detection circuitry includes an H-bridge having a first differential input, a second differential input, and a differential output; a sensing circuit coupled to the differential output of the H-bridge; a comparison and logic circuit coupled to the sensing circuit; a pair of pre-driver circuits coupled to the comparison and logic circuit for driving at least one of the differential inputs of the H-bridge; and a pair of level shifters coupled between the comparison and logic circuit and the sensing circuit. The H-bridge includes a first side having a first transistor coupled to a second transistor, and a second side having a third transistor coupled to a fourth transistor. The first and third transistors are power PDMOS transistors, and the second and fourth transistors are power NDMOS transistors. The pair of level shifters are used to assure that the V<SUB>GS </SUB>of a pair of serially coupled transistors in the sensing circuit do not change with temperature, motor current, or voltage, and each include a transistor receiving a reference current. The pair of level shifters each further includes a serially coupled diode and zener diode for preventing current from flowing from the differential output of the H-bridge to the level-shifting transistor.
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