Patent ID: 6590422
Filing Date: 2003-07-08
Classification: H03M,H04L

Abstract:
A low voltage differential signaling (LVDS) driver for driving differential currents through a load, comprising:four current-steering switches that are serially-connected to form a circuit bridge that defines, between respective pairs of said switches, an upper terminal, a lower terminal and first and second side terminals between said upper and lower terminals; first and second impedance elements serially connected between said first and second side terminals to provide a junction between said first and second impedance elements; a current source that provides a current-source current only to a first selected terminal of said upper and lower terminals; and a feedback-controlled voltage source that receives a feedback signal from said junction and in response to a reference voltage, provides a control voltage only to a second selected terminal of said upper and lower terminals that maintains a junction voltage of said junction substantially equal to said reference voltage wherein said second selected terminal differs from said first selected terminal; said load thereby receiving differential currents having magnitudes substantially equal to said current-source current when said load is coupled between said first and second side terminals and said switches respond to differential input signals; and said junction voltage thereby independent of the magnitude of said current-source current.