A Robust Programmable Static Frequency Divider in Low-Voltage Emitter-Coupled Logic

A programmable 7-bit frequency divider in SiGe BiCMOS technology is presented. The bipolar divider can divide input frequencies up to 5.6 GHz by any number from 57 to 112. To reduce supply voltage and power consumption, emitter followers at the outputs of the flipflops and the logic gates are avoided and used selectively at their inputs. The circuit is functional for any supply voltage between 2.2V and 3.3V for temperatures up to 125 degrees C. It draws 63mA from a single 2.2V supply. Using this divider circuit as an exemplary ECL circuit, a flexible ECL cell library is developed and verified by the divider measurements. The absence of MOS devices makes the library suitable for radiation-hard applications.