GENERAL DESCRIPTION

The AD7949 is an 8-channel, 14-bit, charge redistribution successive approximation register (SAR) analog-to-digital converter (ADC) that operates from a single power supply, VDD.

FEATURES

14-bit resolution with no missing codes

8-channel multiplexer with choice of inputs

Unipolar single-ended

Differential (GND sense)

Pseudobipolar

Throughput: 250 kSPS

INL/DNL: ±0.5/±0.25 LSB typical

SINAD: 85 dB @ 20 kHz

THD: ?100 dB @ 20 kHz

Analog input range: 0 V to VREF with VREF up to VDD

Multiple reference types

Internal selectable 2.5 V or 4.096 V

External buffered (up to 4.096 V)

External (up to VDD)

Internal temperature sensor (TEMP)

Channel sequencer, selectable 1-pole filter, busy indicator

No pipeline delay, SAR architecture

Single-supply 2.3 V to 5.5 V operation with

1.8 V to 5.5 V logic interface

Serial interface compatible with SPI, MICROWIRE,

QSPI, and DSP

Power dissipation

2.9 mW @ 2.5 V/200 kSPS

10.8 mW @ 5 V/250 kSPS

Standby current: 50 nA

20-lead 4 mm × 4 mm LFCSP package

APPLICATIONS

Multichannel system monitoring

Battery-powered equipment

Medical instruments: ECG/EKG

Mobile communications: GPS

Power line monitoring

Data acquisition

Seismic data acquisition systems

Instrumentation

Process control