18-Bit, 100 kSPS PulSAR ADCs in MSOP/LFCSP

The AD7989-1/AD7989-5 are 18-bit, successive approximation, analog-to-digital converters (ADCs) that operate from a single power supply, VDD. The AD7989-1/AD7989-5 contain a low power, high speed, 18-bit sampling ADC and a versatile serial interface port. On the CNV rising edge, the AD7989-1/AD7989-5 sample the voltage difference between the IN+ and IN− pins. The voltages on these pins typically swing in opposite phases between 0 V and VREF. The reference voltage, VREF, is applied externally and can be set independent of the supply voltage, VDD. Its power scales linearly with throughput.

The AD7989-1/AD7989-5 are serial peripheral interface (SPI)-compatible, which features the ability, using the SDI/CS input, to daisy-chain several ADCs on a single 3-wire bus. The AD7989-1/AD7989-5 are compatible with 1.8 V, 2.5 V, 3 V, and 5 V logic, using the separate VIO supply.

The AD7989-1/AD7989-5 are available in a 10-lead MSOP or a 10-lead LFCSP with operation specified from −40°C to +85°C.

Applications

* Automated test equipment

* Data acquisition systems

* Medical instruments

* Machine automation

* High performance

* True differential analog input voltage range: ±VREF

* 0 V to VREF with VREF between 2.4 V and 5.1 V

* Throughput: 500 kSPS/100 kSPS options

* Zero latency architecture

* 18-bit resolution with no missing codes

* INL: ±1 LSB typical, ±2 LSB maximum

* Dynamic range: 99 dB at VREF = 5 V

* SNR: 98 dB at fIN = 1 kHz, VREF = 5 V

* THD: −119 dB at fIN = 1 kHz, VREF = 5 V

* SINAD: 97 dB at fIN = 1 kHz, VREF = 5 V