一种高侧功率开关的输出短路保护电路

提出了一种智能高侧功率开关的短路保护电路,包括输出短路检测电路、延时信号产生电路和栅源电压限制电路。采用NMOS管用作功率管,使电路短路时仍处于安全工作区内,提升了高侧功率开关的可靠性。采用0.6μm HV SOI工艺对该短路保护电路进行了仿真验证。仿真结果表明,在硬开关故障和负载短路两种情况下,功率管保持处于安全工作区内。

A Short-Circuit Protection Circuit Applied in High-Side Power Switch

A short-circuit protection circuit applied in intelligent high side power switch was presented. It included output short-circuit detecting circuit, delay signal generating circuit and gate-source voltage limiting circuit. NMOS transistors were used as the power transistors, so the circuit was still in the safe operating area when the circuit was short, and the reliability of high side power switch were improved. The short-circuit protection circuit was simulated in 0.6 μm HV SOI process. The simulation results showed that the power transistors were keeping in the safe operating area under the condition of hard switch fault and load short-circuit.