AD7170:  12-Bit Low Power Σ−Δ ADC

The AD7170 is a very low power 12-bit analog-to-digital converter (ADC). It contains a precision 12-bit sigma-delta (Σ-Δ) ADC and an on-chip oscillator. Consuming only 135 μA, the AD7170 is particularly suitable for portable or battery operated products where very low power is a requirement. The AD7170 also has a power-down mode in which the device consumes 5 μA, thus increasing the battery life of the product.

For ease-of-use, all the features of the AD7170 are controlled by dedicated pins. Each time a data read occurs, eight status bits are appended to the 12-bit conversion. These status bits contain a pattern sequence that can be used to confirm the validity of the serial transfer. The output data rate of the AD7170 is 125 Hz, whereas the settling time is 24 ms. The AD7170 has one differential input and a gain of 1. This is useful in applications where the user needs to use an external amplifier to implement system-specific filtering or gain requirements.

The AD7170 operates with a power supply from 2.7 V to 5.25 V. It is available in a 10-lead LFCSP package.

The AD7171 is a 16-bit version of the AD7170. It has the same feature set as the AD7170 and is pin-for-pin compatible.

INTERFACE

• 2-wire serial (read-only device)
• SPI compatible
• Schmitt trigger on SCLK

APPLICATIONS

• Pressure measurement
• Industrial process control