Texas Instruments DDC3256 24-Bit 256-Channel ADC

Texas Instruments DDC3256 24-Bit 256-Channel Analog-to-Digital Converter (ADC) combines current-to-voltage conversion by current integration and A/D conversion. Up to 256 individual low-level current output devices, such as photodiodes, can be directly connected to the device's inputs and digitized in parallel (simultaneously). For each of the 256 inputs, the device has one low power and low noise integrator designed to capture all the charge from the sensor. The integration time is adjustable from 50µs to 1.6ms, allowing currents in the order of fA to µA to be measured with outstanding precision continuously. The outputs of the integrators are digitized by on-chip low-power ADCs, and the converted digital codes are transmitted over a single LVDS pair designed to minimize noise coupling in environments with high channel counts.