ADS7871

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


Application

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


Pinout




Specifications

			UNIT
Supply voltage, VDD			5.5 V
Analog inputs	Input current	Momentary	100 mA
		Continuous	10 mA
	Input voltage		VDD + 0.5 V to GND − 0.5 V
Operating free-air temperature range, TA			−40°C to 85°C
Storage temperature range, TSTG			−65°C to 150°C
Junction temperature (TJ max)			150°C
Lead temperature, (10 sec)			300°C

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

The ADS7871 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 ADS7871 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 of ADS7871 allows the use of SPI™, QSPI™,Microwire™, and 8051-family protocols, without glue logic.