1 MSPS, 4-Channel, 16-Bit Dual, Simultaneous Sampling SAR ADCs

The AD4684/AD4685 are 16-bit, dual, simultaneous sampling, high speed, successive approximation register (SAR), analog-to-digital converters (ADCs) that operate from a 3.0 V to 3.6 V power supply and feature throughput rates of up to 1 MSPS for the AD4684 and 500 kSPS for the AD4685. The analog input types are single-ended and are sampled and converted on the falling edge of CS.

The AD4684/AD4685 have an on-chip sequencer and integrated on-chip oversampling block to improve dynamic range and reduce noise at lower bandwidths. A buffered internal 2.5 V reference is included. Alternatively, an external reference up to 3.3 V can be used. The conversion process and data acquisition use standard control inputs, allowing interfacing to microprocessors or digital signal processors (DSPs). The AD4684/AD4685 is compatible with 1.8 V, 2.5 V, and 3.3 V interfaces by using the separate logic supply. The AD4684/AD4685 are available in a 16-lead, 3 mm × 3 mm lead frame chip scale package (LFCSP) with operation specified from −40°C to +125°C.

PRODUCT HIGHLIGHTS

* 4-channel, dual simultaneous sampling ADC.

* Pin-compatible product family.

* High throughput rate: 1 MSPS (AD4684) and 500 kSPS (AD4685).

* Space-saving, 16-lead, 3 mm × 3 mm LFCSP.

* Integrated oversampling block to increase dynamic range and SNR and to reduce SCLK speed requirements.

* Single-ended analog inputs.

* Small sampling capacitor reduces amplifier drive burden.

APPLICATIONS

* Motor control position feedback

* Motor control current sense

* Sonars

* Power quality

* Data acquisition systems

* Erbium doped fiber amplifier (EDFA) applications

* Inphase and quadrature demodulation

* 16-bit dual simultaneous sampling SAR ADC

* Single-ended analog inputs

* 4-channel with 2:1 multiplexers

* Channel sequencer mode

* Throughput rate

* 1 MSPS (AD4684)

* 500 kSPS (AD4685)

* SNR (typical)

* 87.5 dB with VREF = 3.3 V external

* 93 dB with OSRMODE = 1, OSR = 8, RES = 1, VREF = 2.5 V internal