General Description
The MAX11156 18-bit, 500ksps, SAR ADC offers excellent AC and DC performance with true bipolar input range, small size, and internal reference. The MAX11156 measures a ±5V (10VP-P) input range while operating from a single 5V supply. A patented charge-pump architecture allows direct sampling of high- impedance sources. The MAX11156 integrates an optional 6ppm/°C reference with internal buffer, saving the cost and space of an external reference.
The MAX11156 produces 94.6dB SNR and -105dB THD (typ). The MAX11156 guarantees 18-bit no-missing codes. The MAX11156 communicates using an SPI-compatible serial interface at 2.5V, 3V, 3.3V, or 5V logic. The serial interface can be used to daisy-chain multiple ADCs in parallel for multichannel applications and provides a busy indicator option for simplified system synchronization and timing.
The MAX11156 is offered in a 12-pin, 3mm x 3mm, TDFN package and is specified over the -40°C to +85°C temperature range.

Features
● High DC and AC Accuracy
● 18-Bit Resolution with No Missing Codes
● SNR: 94.6dB
● THD: -105dB at 10kHz
● ±2.5 LSB INL (typ)
● ±0.4 LSB DNL (typ)
● Internal Reference and Reference Buffer Save Cost
   and Board Space
● 6ppm/°C (typ)
● Tiny 12-Pin 3mm x 3mm TDFN Package
● Bipolar ±5V Analog Input Range Saves External
   Signal Conditioning
● Single-Supply ADC with Low Power
● 5V Analog Supply
● 2.3V to 5V Digital Supply
● 26.5mW at 500ksps
● Shutdown Mode
● 500ksps Throughput Rate
● No Pipeline Delay/Latency
● Flexible Industry-Standard Serial Interface Saves I/O Pins
● SPI/QSPI™/MICROWIRE®/DSP-Compatible

Applications
● Data Acquisition Systems
● Industrial Control Systems/Process Control
● Medical Instrumentation
● Automatic Test Equipment