LTC2440

The LTC^®2440 is a high speed 24-bit No Latency ^TM ADC with 5ppm INL and 5mV offset. It uses proprietary deltasigma narchitecture enabling variable speed and resolution with no latency. Ten speed/resolution combinations (6.9Hz/ 200nV_RMS to 3.5kHz/25V_RMS) are programmed through a simple serial interface. Alternatively, by tying a single pin HIGH or LOW, a fast (880Hz/2V_RMS) or ultralow noise (6.9Hz, 200nVRMS, 50/60Hz rejection) speed/resolution combination can be easily selected. The accuracy (offset, full-scale, linearity, drift) and power dissipation are independent of the speed selected. Since there is no latency, a speed/resolution change may be made between conversions with no degradation in performance.

Following each conversion cycle, the LTC2440 automatically enters a low power sleep state. Power dissipation may be reduced by increasing the duration of this sleep state. For example, running at the 3.5kHz conversion speed but reading data at a 100Hz rate draws 240mA average current (1.1mW) while reading data at 7Hz output rate draws only 25mA (125W).

The LTC2440 communicates through a flexible 3- or 4-wire digital interface that is compatible with the LTC2410.