TIDA-01583: Ultra-Low Noise Bias Voltage Reference Design for Microbolometer Detectors

Uncooled microbolometer detectors require accurate and ultra-low noise bias voltages for their operation. Such requirements cannot be simply met by switching power supplies, LDO or DAC outputs. Enabled by Texas Instruments’ precision DAC, low noise precision amplifier and high PSRR, low noise LDO, this reference design demonstrates how to generate accurate and ultra-low noise programmable bias voltages and power supplies for uncooled microbolometer detectors at low cost.

Features

• Total output noise < 4µVRMS from 0.1Hz to 1MHz

• Voltage accuracy better than ±10mV

• Based on a true 16-bit, R-2R DAC with buffered rail-to-rail voltage output

• Four programmable voltage outputs

• Easily scalable in terms of DAC resolution, voltage range, number of channels

• Output current capability: 10mA (without BJT) and 75mA (with external BJT)