Main components of half bridge module power supply
2022-03-06

The half bridge circuit includes a low-end drive module (110) and a high-end drive module (210) for driving each lower transistor (T1) and upper transistor (T2). Each drive module (110210) is a charge capture circuit, in which the low-end drive module (110) drives the low-end transistor (T1) with the charge on the capacitive load (c), and the high-end drive module (210) alternately recharges the capacitive load (c) when it is driven by a high voltage source. Each charge capture circuit (110210) also includes diodes (D1, D2), which prevent unintentional loss of charge on the gate of the driven transistors (T1, T2), and Zener Diodes (Z1, Z2), which clamp the gate voltage at a safe level. In this way, the half bridge circuit is effectively driven without auxiliary power supply.


An upper transistor control circuit (HS) for driving the upper transistor (T2) by applying a signal to the control end of the upper transistor (T1); And a lower transistor control circuit (110) for driving the lower transistor (T1) by applying a signal to the control end of the lower transistor (T1). The lower transistor control circuit (110) includes: a third transistor (T3), which has a drain connected to the output end (120), and a source connected to the anode of the diode (D1), the cathode of which is connected to the control end of the lower transistor (T1); And a fourth transistor (T4) having a drain connected to the control end of the lower transistor (T1) and a source connected to a rail for applying a low DC voltage.