Amplifiers – Modulator-demodulator-type amplifier
Patent
1987-10-28
1989-06-27
Mullins, James B.
Amplifiers
Modulator-demodulator-type amplifier
328151, 437 60, 437226, H03F 338
Patent
active
048433390
ABSTRACT:
An isolation amplifier includes a voltage-to-duty-cycle modulator, a non-galvanic isolation barrier, and a demodulator converting a duty-cycle-modulated signal transmitted across the isolation barrier to an analog voltage replica of the analog input voltage. The modulator circuit includes a first current switching means which produces a first current that is switched between positive and negative values in response to an output from a comparator that can be referenced to a noise-synchronized signal. The first current is summed with an input current and the difference is integrated and input to the comparator, the output of which produces the duty-cycle-modulated signal. The demodulator includes a second current switching circuit for producing a second current that is switched between positive and negative levels in response to the duty-cycle-modulated signal received across the isolation barrier and includes circuitry for algebraically summing the input current with the second current and integrating the result to produce the analog output voltage. The modulator circuit and demodulator circuits are fabricated on a single semiconductor area to produce the close matching between components of the first and second current switching circuits. The area is cut in half to produce two chips, which are connected to two isolation barrier capacitors. In the demodulator, a sample and hold circuit synchronized with the duty-cycle-modulated signal transmitted across the isolation barrier samples the output of the integrator.
REFERENCES:
patent: 3441877 (1969-04-01), Thompson
patent: 3596191 (1971-07-01), Stuckert
patent: 3636458 (1972-01-01), Sugiyama et al.
patent: 3740586 (1973-06-01), Banks et al.
patent: 3936674 (1976-02-01), Hughes
patent: 3982193 (1976-09-01), Maringer
patent: 4156923 (1979-05-01), Lampe et al.
patent: 4166248 (1979-08-01), Bianchi et al.
patent: 4249136 (1981-02-01), Suzuki et al.
patent: 4408166 (1983-10-01), Moeller
patent: 4415863 (1983-11-01), Tokumo
patent: 4504793 (1985-03-01), Yokoyama
patent: 4588954 (1986-05-01), Seymour
Klynin, "Direct-Current Amplifier with Frequency-pulse-width modulation", Instrum. & Exp. Tech. (U.S.A.) vol. 19, No. 5, Sep.-Oct. 1976 pp. 1415-1417.
Burt Rodney T.
Stitt, II Robert M.
Burr-Brown Corporation
Mullins James B.
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