14-Bit, 8-Channel, 250 SPS PulSAR ADC

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.

The AD7949 contains all components for use in a multichannel, low power data acquisition system, including a true 14-bit SAR ADC with no missing codes; an 8-channel, low crosstalk multiplexer that is useful for configuring the inputs as single-ended (with or without ground sense), differential, or bipolar; an internal low drift reference (selectable 2.5 V or 4.096 V) and buffer; a temperature sensor; a selectable one-pole filter; and a sequencer that is useful when channels are continuously scanned in order.

The AD7949 uses a simple SPI interface for writing to the configuration register and receiving conversion results. The SPI interface uses a separate supply, VIO, which is set to the host logic level. Power dissipation scales with throughput.

The AD7949 is housed in a tiny 20-lead LFCSP with operation specified from −40°C to +85°C.

APPLICATIONS

* Multichannel system monitoring

* Battery-powered equipment

* Medical instruments: ECG/EKG

* Mobile communications: GPS

* Personal digital assistants

* Power line monitoring

* Data acquisition

* Seismic data acquisition systems

* Instrumentation

* Process control

* 14-bit resolution with no missing codes

* 8-channel multiplexer with choice of inputs

Unipolar single-ended

Differential (GND sense)

Pseudobipolar