A CMOS 0.8 μm fully differential current mode buffer for HF SI circuits

Abstract

We present a high-frequency fully-differential current-mode buffer to interface off-chip currents with no significant degradation of the frequency response, and to measure current-mode ICs using standard equipment. It has been fabricated in a 0.8μm double-poly double-metal CMOS technology and features more than 37MHz bandwidth. In order to show its functionality, this unit has been incorporated to the front end of a Switched-Current Band-Pass ΣΔ modulator featuring 9 bit dynamic range at 10MHz clock frequency for a 30kHz signal bandwidth centered at 2.5MHz.