用 N 沟道功率 MOSFET(以下简称 N 管)作低端驱动(N 管在负载的下面)是最简单的,尤其是采用 TTL 逻辑电平控制的 N 管,只要在栅极端加高电平,N 管导通,负载得电工作;栅极端加低电平,N 管截止,负载不工作,如图1所示。但这种电路的负载不接地,若要求负载接地则需要用高端驱动(N 管在负载的上面),如图2所示。此时不能采用在栅极上加 TTL 电平来控制。栅极对地的电压 V_G 可用图3来说明: N-channel power MOSFET (N tube) for the low-side driver (N tube under the load) is the most simple, especially the use of TTL logic level control of the N tube, as long as the gate end of the high level, N tube conduction, the load is working; gate plus low level, N tube deadline, the load does not work, as shown in Figure 1. However, the load of this circuit is not grounded. If it is required to ground the load, high-side drive (N-tube on the load) is required, as shown in Figure 2. At this point can not be used in the gate plus TTL level control. The voltage V_G of the gate to ground can be illustrated by FIG. 3: