Dynamic CMOS power-up current surge control circuit.

A CMOS chip, which consists of many dynamic cells, may consume tremendous current during system power-up. As a result, the system power supply may be tripped during the power-up if more than several CMOS chips which contain many dynamic cells are used. A new power-up surge current control circuit has been developed and used in ADPCM Transcoder Device (140BC). This memorandum describes functionality of the power-up surge current control circuit and presents the test results. The new ADPCM only consumes approximately 1/30 of the power-up surge current of the old ADPCM (~-20mA vs ~-600mA).