Fight-channel multiplexed SAR ADC with sequencer combines performance with configurability

Linear Technology has introduced the LTC2373-18, a new eight-channel, 18-bit, 1Msps successive approximation register (SAR) ADC with exceptional 100dB SNR performance and configurability. 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. This provides the ability to easily 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 device heads a family of 16-/18-bit 8-channel multiplexed SAR ADCs that communicate over SPI-compatible interfaces, feature sample rates of 500ksps and 1Msps, and 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 20ppm/C maximum temperature coefficient and a high performance reference buffer into a small 25mm² QFN-32 package. The device is powered from a single 5V supply and consumes only 40mW at 1Msps. The LTC2373-18 is available today in commercial, industrial and automotive (-40C to 125C) temperature grades. An evaluation board, the DC2071A is also available.