Motorola Corporation

James A Miller

Mathew A Rybicki

Michael D Smith

Richard W Ulmer

Robert N Allgood

Douglas W Nickerson

Ted A Biggs, Deceased

A method for directly providing a conversion of an analog input signal to a digital signal in two's complement code with a sampled data converter. Positive and negative reference voltages and an analog ground voltage are required. After a sign bit determination of the input signal is made, the data converter is coupled between either a first pair of reference voltages or a second pair of reference voltages depending upon the sign bit. The first pair of reference voltages comprises the positive reference and ground reference, and the second pair of reference voltages comprises the ground reference and a negative reference. By selectively coupling the chosen reference voltages to the converter, a converter may directly output two's complement code.

Data converter for directly providing outputs in two's complement code

A voltage detecting circuit is provided for generating an output signal when an input signal exceeds the power supply voltage by a predetermined amount. A reference current is established by an output stage using a first current mirror. A second current mirror is connected to the output stage and detects the input voltage level by forcing a greater or lesser amount of current through the output stage to provide a high or low level output voltage.

High voltage detection circuit

A charge pump amplifier useful for providing precise gain in integrated circuits is described. The amplifier uses an operational amplifier with a capacitive feedback to accumulate successive charges applied to the input of the operational amplifier by a switched-capacitor input. If the capacitors are of equal size, the gain of the amplifier is a function of the ratio of the frequency of the switched capacitor input and the frequency of discharge of the feedback capacitor.

Charge pump amplifier

A power supply circuitry including an input DC voltage source, a DC to DC up converter for converting the input DC voltage to an output DC voltage of greater magnitude and means for enabling the up converter to change the magnitude of the output DC voltage. The output voltage is further smoothed and filtered by a DC to DC series regulator.

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Austin, TX, United States of America

James A Miller