Smallest 18-Bit SAR ADC saves 70% PCB area

May 14, 2013 // By Graham Prophet
Maxim's bipolar successive-approximation register (SAR) ADC integrates a reference buffer and internal reference while offering excellent AC and DC performance.

Maxim Integrated is now supplying the MAX11156, the smallest-available 12-pin, 18-bit successive approximation register (SAR) analogue-to-digital converter (ADC). Available in a 3 x 3mm TDFN package, the MAX11156 integrates an internal reference and reference buffer, saving cost and at least 70% board space over competing solutions. With 18-bit resolution, this high-performance ADC features Beyond-the-Rails technology, which supports a ±5V input from a single positive 5V input rail. This technology eliminates the need for negative power supplies and simplifies designs. With 18-bit resolution and a 500 ksamples/sec sampling rate, the MAX11156 is suitable for automatic test equipment (ATE), industrial control systems, medical instrumentation, and robotics, where high accuracy and tiny size are paramount.

Due to its monotonic transfer characteristic, fast settling time, and lack of latency, the MAX11156 is suited to fast, high-precision digital control-loop systems. It provides 18-bit resolution with no missing codes; excellent DC accuracy (0.5 LSB DNL and 2.5 LSB INL (typ)); and excellent AC performance (94.6dB SNR and -105dB THD (typ)). Additionally, the MAX11156 communicates using an SPI-compatible serial interface, which can be used to daisy-chain multiple ADCs in parallel for multichannel applications. This interface can also provide a busy indicator to simplify system synchronisation and timing. Specified over the -40°C to +85°C temperature range, pricing starts at $16.90 (1000).

Maxim Integrated, www.maximintegrated.com