FEATURES

PGA Gains: 1, 2, 4, 5, 8, 10, 16, 20 V/V

Programmable Input (Up to 4-Channel

Differential/Up to 8-Channel Single-Ended or

Some Combination)

1.15-V, 2.048-V, or 2.5-V Internal Reference

SPI/DSP Compatible Serial Interface

(≤ 20 MHz)

Throughput Rate: 52 kSamples/sec

Error Overload Indicator

Programmable Output 2s Complement/Binary

2.7-V to 5.5-V Single Supply Operation

4-Bit Digital I/O Via Serial Interface

Pin-Compatible With ADS7871

SSOP-28 Package

APPLICATIONS

Portable Battery-Powered Systems

Low-Power Instrumentation

Low-Power Control Systems

Smart Sensor Applications

DESCRIPTION

The ADS7870 (US patents 6140872, 6060874) is a

complete low-power data acquisition system on a single

chip. It consists of a 4-channel differential/8-channel

single-ended multiplexer, precision programmable gain

amplifier, 12-bit successive approximation analog-todigital

(A/D) converter, and a precision voltage reference.

The programmable-gain amplifier provides high input

impedance, excellent gain accuracy, good common-mode

rejection, and low noise.

For many low-level signals, no external amplification or

impedance buffering is needed between the signal source

and the A/D input.

The offset voltage of the PGA is auto-zeroed. Gains of 1,

2, 4, 5, 8, 10, 16, and 20 V/V allow signals as low as 125

mV to produce full-scale digital outputs.

The ADS7870 contains an internal reference, which is

trimmed for high initial accuracy and stability vs

temperature. Drift is typically 10 ppm/°C. An external

reference can be used in situations where multiple

ADS7870s share a common reference.

The serial interface allows the use of SPI?, QSPI?,

Microwire?, and 8051-family protocols, without glue logic.