18-bit, 1 Msps, 8-channel multiplexed ADC with sequencer

February 13, 2015 // By Graham Prophet
LTC2373-18 is an 8-channel, 18-bit, 1 Msample/sec successive approximation register (SAR) ADC with 100dB SNR performance. The LTC2373-18 is equipped with a programmable sequencer that can store up to 16 control words for configuring the multiplexer (MUX) and input range.

The addition of the sequencer provides the ability to mix and match fully differential and pseudo-differential input ranges with a variety of MUX channel configurations. Single-ended input signals may also be converted to the fully differential input range of the ADC core by sharing a single external driver circuit between the MUXOUT/ADCIN pins available on the device. This enables the user to achieve the full 100dB SNR performance of the ADC on eight single-ended inputs.

The LTC2373-18 leads a family of 16-/18-bit 8-channel multiplexed SAR ADCs that communicate over SPI-compatible interfaces, feature sample rates of 500 ksamples/sec and 1 Msamples/sec, that achieve 100dB SNR at 18 bits, and 96dB SNR at 16 bits, with the ±4.096V fully differential input range. The LTC2373 family integrates a precision bandgap reference with low drift and guaranteed 20 ppm/°C maximum temperature coefficient and a high performance reference buffer into a 25 mm² QFN-32 package. The device is powered from a single 5V supply and consumes only 40 mW at 1 Msamples/sec.

In commercial, industrial and automotive (-40°C to 125°C) temperature grades, pricing begins at $17.35 (1,000). The DC2071A evaluation board for the LTC2373 SAR ADC family is available at www.linear.com/demo

Linear Technology; www.linear.com/product/LTC2373-18