BIPOLAR_OUTPUT

Published:2009/6/30 21:24:00 Author:May | From:SeekIC

Low-cost voltage-to-fre-quency converter IC is here used in A/D converter circuit that will accept bipolar inputs and generate positive-going pulses to indicate positive input voltages and negative-going pulses for negative input voltages. Opamps A1 and A2 form negative-output absolute-value circuit that feeds opamp A3 and RC4151 voltage-to-frequency converter, for generating 10-μs negative-going pulses with repetition-rate scale factor of 1 kHz/V. Full-scale input is 20 V P-P.Opamp A4 is ground-referenced voltage comparator having zener clamp, providing TTL-compatible logic output for indicating input polarity. Pulse-receiver/decoder section takes digitally coded signals arriving from transmitter, for processing by data line or D flip-flop and two trigger inputs of dual-edge retriggerable mono MVBR This generates 25-μs negative-going output pulse for each 10-μs input pulse from data line. Logic 1 on complementary output of flip-flop indicates that original input voltage to transmitter was positive.—E. J.DeWath, Low-Cost A/D Converter Transmits and Receives, EDN Magazine, Jan. 5, 1977, p 35.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Basic_Circuit/BIPOLAR_OUTPUT.html

Print this Page | Comments | Reading(3)