ANALOG DEVICES DC742B

DC742B demonstration circuit features the LTC®2449, an 8-/16-channel, high speed, 24-bit Δ∑ ADC with ten selectable speed/resolution modes from 6.9Hz/200nVRMS to 3.5KHz/23μVRMS (4KHz with external oscillator). Key DC specifications include 5ppm INL, 5μV offset, 10ppm full-scale error and 20nV/°C offset drift. In the 6.9Hz/200nVRMS mode, input normal mode rejection of 50Hz and 60Hz noise is better than 87dB. The accuracy (offset, full-scale, linearity, drift) and power dissipation are independent of the speed selected. The LTC2449 performs auto-zeroing of the ADC by reversing the inputs through the multiplexer output/ADC input connections. This allows an external dual buffer amplifier to isolate the signal inputs from the sampling current of the ADC. It is designed to allow easy evaluation of the LTC2449 and may be connected directly to the target application’s analogue signals while using the DC590 USB serial controller board and supplied software to measure performance.