Bias generating circuit for use with an oscillating circuit in an integrated circuit charge pump

摘要

In an improved charge pump bias generating circuit for a charge pump for a semiconductor integrated circuit device, the pump has a bias generator which has an input for receiving a pump enable signal. The bias generator generates a ramped bias signal in response to the pump enable signal. A voltage controlled oscillator has an input to receive the ramped bias signal and generates an oscillating signal having a frequency which is dependent upon the voltage of the ramped bias signal. As a result, the sudden turn on of the pump enable signal would cause a gradual turn on of the voltage controlled oscillator gradually turning on the clock output signal from the voltage oscillator, thereby reducing power surge in the circuit.