16-Bit, Single-Channel, Ultra Low Power, Sigma-Delta A/D Converter

The AD7788/AD7789 are low power, low noise, analog front ends for low frequency measurement applications. The AD7789 contains a low noise, 24-bit, ∑-∆ analog-to-digital converter (ADC) with one differential input. The AD7788 is a 16-bit version of the AD7789.

The devices operate from an internal clock. Therefore, the user does not have to supply a clock source to the devices. The output data rate is 16.6 Hz, which gives simultaneous 50 Hz/60 Hz rejection.

The devices operate with a single power supply from 2.5 V to 5.25 V. When operating from a 3 V supply, the power dissipation for the device is 225 µW maximum. The AD7788/AD7789 are available in a 10-lead MSOP.

Applications

* Smart transmitters

* Battery applications

* Portable instrumentation

* Sensor measurement

* Temperature measurement

* Pressure measurement

* Weigh scales

* 4 to 20 mA loops

* 16-bit resolution

* Power

* Supply: 2.5 V to 5.25 V operation

* Normal: 75 µA maximum

* Power-down: 1 µA maximum

* RMS noise: 1.5 µV

* 16-bit p-p resolution

* Integral nonlinearity: 3.5 ppm typical

* Simultaneous 50 Hz and 60 Hz rejection

* Internal clock oscillator

* VDD monitor channel

* 10-lead MSOP