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: 48 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 ADS7870
SSOP-28 Package

APPLICATIONS
Portable Battery-Powered Systems
Low-Power Instrumentation
Low-Power Control Systems
Smart Sensor Applications

DESCRIPTION
The ADS7871 (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, 14-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 ADS7871 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
ADS7871s share a common reference.
The serial interface allows the use of SPI, QSPI,
Microwire, and 8051-family protocols, without glue logic.