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Digitally Controlled Integrated Bipolar Charge Pump

IP.com Disclosure Number: IPCOM000068861D
Original Publication Date: 1978-Mar-01
Included in the Prior Art Database: 2005-Feb-20

Publishing Venue

IBM

Related People

Authors:
Crauwels, GL Hession, JJ Kraft, WR Nawy, AA [+details]

Abstract

This circuit generates a precision ramp waveform with a scope > 0 from a single power supply and features the generation of double ramp voltages driven by an external time base. The double ramp signal is used in many applications, such as power supplies, analog-to-digital (A/D) connectors, etc. It is presently used in the IBM Series/1 power supply. Controlled saturation prevents the whole ramp waveform from drifting randomly, without using elaborate computational circuitry. The only alternative is to use a digital-to-analog converter (DAC) and counters. This is expensive and results in quantization noise on the ramp.