Coded data generation or conversion – Converter compensation
Patent
1989-04-10
1991-02-26
Shoop, Jr., William M.
Coded data generation or conversion
Converter compensation
307359, H03M 106
Patent
active
049965298
ABSTRACT:
An improved auto-zeroing feedback control circuit (FIG. 1) is disclosed to compensate for DC offset voltages in signal coding applications. The feedback control circuit for a signal limiter (120) includes a digital integrator (130) which oversamples the limited output (125). When the accumulated sample count overflows, an analog integrator (140) is enabled, and a small quantity of charge is delivered to the integrating capacitor. The analog integrator output signal (145) is then attenuated (150) and used to adjust the bias for the limiter (120). This improved auto-zeroing technique eliminates the requirement of a large external auto-zero capacitor, and permits the signal coder to be fully integrated on-chip.
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Hoff Marc S.
Melamed Phillip H.
Motorola Inc.
Shoop Jr. William M.
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