集成的BiCMOSDC/DC开关电源控制器输出驱动电器的低功耗设计

Low Power Design for the Output-Driver Circuit of Integrated BiCMOS DC/DC Switching Regulator Controller

为使 DC/DC开关电源的功率开关管及时地导通或截止 ,需要设计专用的输出驱动电路。基于整个开关电源系统低功耗的考虑 ,开关电源可以采用同步整流的拓扑结构[1] 。该拓扑结构需要一个电压自举的输出驱动电路。本文首先提出了一种有自举功能的 Bi CMOS工艺的输出驱动电路 ,在此基础上 ,采用电流源和电流沉串联的方式改进了前面提出的输出驱动电路。通过消除 CMOS电路的瞬态短路导通现象 ,不仅降低了该电路模块的功耗 ,而且起到了保护的作用。经 HSPICE模拟表明 :开关电源的输入电压 Vin为1 0 V控制器内部电压 [VL]为 5V,开关频率为 2 0 0 k Hz时 ,改进驱动电路的功耗降低了约 1 1 .5% ,同时避免了瞬态短路导通现象。

In order to switching the power transistor on or off quickly in DC/DC switching regulator, it is necessary to design a special output driver circuit. For the lower power of the whole system, the switching regulator can use the configuration of synchronous rectification [1] . This circuit needs a driver circuit with voltage self boost. This paper presents, firstly, a output driver circuit with voltage self boost in BiCMOS process, then on the basis of the previous circuit, this paper presents a better circuit using the configuration of the current source and current sink in series. The better circuit not only reduces the power of the circuit, but also has the protect function by eliminating the phenomenon of transient short circuit in CMOS circuits. The result of simulation using HSPICE demonstrated that the better circuit′s power reduces about 11.5% and avoids the phenomenon of transient short circuit in CMOS circuits when the input voltage is equal to 10 V, the interior voltage of controller of switching regulator, [VL],is at 5 V, the frequency of switch is at 200 kHz.