Analog doubles speed of fastest 18-bit SAR A/D converter

September 04, 2013 // By Graham Prophet
Analog Devices' AD7960 18-bit PulSAR A/D converter has 5-Msamples/sec throughput, a figure that ADI says is twice the speed of any available SAR (successive-approximation register) converter.

It also, the company adds, leads in noise floor and linearity; the AD7960 PulSAR A/D converter was designed for low-power signal chains, multiplexed systems such as digital X-ray, and oversampling applications including spectroscopy, MRI gradient control and gas chromatography.

Unlike other 18-bit A/D converters, which sacrifice power and accuracy to achieve higher sample rates, the AD7960 consumes 39 mW at 5 Msamples/sec and is optimised for DC linearity ( ±0.8 LSB INL) and AC performance (99dB SNR) even at full throughput. The new converter also features lowest noise floor (22.4 nV/√Hz) relative to its full scale input, which combined with a small package size helps designers meet space, thermal, power and other key design challenges common to high-channel-density systems.

In the same release is the AD7961 16-bit PulSAR A/D converter, which achieves excellent SNR (signal-to-noise ratio) performance (95.5 dB) and INL (+/- 0.2 LSB INL) at 5-Msamples/sec.

The AD7961 and AD7960 PulSAR A/D converters provide a pin-compatible upgrade/downgrade path for 16- and 18-bit data acquisition applications in instrumentation and healthcare. They include a flexible, low-noise LVDS (low-voltage differential signalling) interface which transfers data off chip at speeds up to 300 MHz.

Related evaluation tools such as reference circuits, development kits and FPGA mezzanine cards include all HDL code and device drivers for easy integration with FPGAs and support faster development in a simplified design environment. In 5 x 5 mm, 32-lead LFCSP they cost, respectively, $31 and $21 (1000).

Analog Devices; /

A reference design is at;