James D. Strom,Grant P. Kesselring,Ann Chen Wu,Scott R. Trcka
申请号：
US15825903
公开号：
US10361707B2
申请日:
2017.11.29
申请国别(地区):
US
年份:
2019
代理人:
摘要：
A system and apparatus relating to a differential charge pump circuit for use in a phase-locked loop (PLL) circuit. A differential charge pump circuit can include a reference current, two sense amplifiers, a common mode control amplifier, and an h-bridge circuit. The h-bridge circuit is coupled to the reference current and the common mode control amplifier. The reference current drives a first portion of the h-bridge circuit and the common mode control amplifier controls a second portion of the h-bridge circuit. The h-bridge circuit also includes first and second nodes. The nodes are inputs to one of the sense amplifiers. The differential charge pump circuit is configured to control a voltage at the first node so that it is substantially equal to a voltage at the second node for a plurality of voltages at the second node. The differential charge pump circuit can also include a transistor with a gate coupled to an output of a sense amplifier. The voltage at the first node can be controlled by the sense amplifier and the transistor.
