Pll charge pump with reduced coupling to bias nodes

A charge pump comprising:

• a charge pump output node;
• a first current mirror circuit that conducts a first current mirror current from the charge pump output node when a first charge pump input signal has a first logic level;
• a second current mirror circuit that conducts a second current mirror current onto the charge pump output node when a second charge pump input signal has a second logic level;
• a first replica circuit that is a replica of a portion of the first current mirror circuit, wherein the first replica circuit conducts a first replica current when an inverted version of the first charge pump input signal has the first logic level, and wherein a gate of a transistor of the first replica circuit is coupled to a bias node of a current mirror of the first current mirror circuit;
• and
• a second replica circuit that is a replica of a portion of the second current mirror circuit, wherein the second replica circuit conducts a second replica current when an inverted version of the second charge pump input signal has the second logic level, and wherein a gate of a transistor of the second replica circuit is coupled to a bias node of a current mirror of the second current mirror circuit.

An apparatus comprising:

• a charge pump output node;
• a first charge pump input node that receives a charge pump input signal;
• a second charge pump input node that receives an inverted version of the charge pump input signal;
• a current mirror having a bias node, wherein the current mirror is adapted to initiate a flow of current from the charge pump output node to a ground node in response to a transition of the charge pump input signal, wherein there is a first coupling effect between the transition of the charge pump input signal and a voltage on the bias node;
• and
• means for reducing a voltage disturbance on the bias node of the current mirror by inducing a second coupling effect between a transition of the inverted version of the charge pump input signal and the voltage on the bias node, wherein the first and second coupling effects are of opposite magnitudes.