Power up signal generator

摘要

A power up signal generator includes a signal converter for converting an applied external source voltage to a voltage applied at a trigger node when the external source voltage rises to a first threshold, and a current source for flowing a reference current from the trigger node. A first inverter connected to the trigger node outputs a low level signal when the trigger node voltage reaches a second threshold. A second inverter outputs a power up signal after receiving the low level signal from the first inverter. The signal converter may include a PMOS transistor configuration, such that the trip voltage of the power up signal generator is dependent only on a single MOSFET transistor threshold voltage.