A fast automatic power control circuit for a small form-factor pluggablelaser diode drive~*

摘要

A fast automatic power control (APC) circuit for a laser diode driver (LDD) has been implemented in a 0.6-μm BiCMOS process. The APC circuit adopts double-loops and variable-bandwidth techniques to achieve a turn-on time of < 400 μs for most kinds of TOSAs. Thus, it meets the small form-factor pluggable (SFP) agreement. Such techniques make a good tradeoff between stability, accuracy, turn-on time, noise and convenience. The measured results indicate that the APC circuit is suitable for SFP LDD.