Burr-brown Corporation

David F Mietus

Jimmy R Naylor

Robert L White

An integrated circuit digital-to-analog converter includes a nichrome feedback resistor having .+-.1% accuracy in its output amplifier, a plurality of bit current determining resistors that have .+-.30% manufacturing accuracy, a bias voltage circuit that produces a temperature-compensated bias voltage including an integrated potentiometer that is laser trimmed to compensate for the inaccuracy of the bit current determining resistors. The bit current determining resistors thereby produce constant, precise temperature-independent bit currents. The integrated potentiometer is accurately laser trimmed without changing the series resistance of the potentiometer. This prevents current density changes that change the temperature sensitivity of temperature-compensating elements in the bias voltage circuit.

Low cost digital-to-analog converter with high precision feedback

A low voltage sixteen bit digital-to-analog converter operable between +5 and -5 volt power supplies and capable of providing output voltage levels to within about 1.4 volts of +V.sub.CC and -V.sub.CC includes a push-pull output stage with only a pullup transistor and a pulldown transistor connected in series between the positive and negative supply voltages. The output stage includes circuitry that reduces the base voltage of the pullup transistor or pulldown transistor enough to reduce its collector current to near zero, greatly increasing its effective collector-to-emitter breakdown voltage.

Growing community of inventors

Tucson, AZ, United States of America

David F Mietus