The invention provides a switching constant-current controller and a switching constant-current power
driving circuit. The switching constant-current controller comprises an output
voltage detection pin, a grounding pin, a grid pin, a drain pin, an
electrostatic discharge device and a driving module, wherein the grid pin is connected with a grid of an external
power switching tube. The drain pin is connected with the drain
electrode of the
power switching tube; the
electrostatic discharge device comprises an NMOS tube, the source
electrode of the NMOS tube is grounded, and the drain electrodeof the NMOS tube is connected with the output
voltage detection pin. The driving module is connected with the grid
electrode and the grid electrode pin of the NMOS tube, and is used for controlling the
power switching tube and the NMOS tube to be switched on or off in the same time period, so as to ensure that a parasitic reverse body
diode of the NMOS tube is not switched on when the
voltage at the output voltage detection pin is a
negative voltage. According to the invention, the risk that the controller triggers the latch-up effect can be effectively reduced, and the offset of reference voltage and
reference current can be reduced.