Analog Devices Inc. AD4697 & AD4698 Easy Drive Multiplexed SAR ADCs
Analog Devices Inc. AD4697 and AD4698 Easy Drive Multiplexed SAR ADCs offer compactness, high accuracy, low power, 8-channels, 16-bits, 500kSPS/1MSPS, multiplexed input precision, successive approximation register (SAR) with Easy Drive and extensive digital functionality. The AD4697 and AD4698 are designed for space-constrained, multichannel, precision data acquisition systems and monitoring circuits.
The ADI AD4697 and AD4698 ADCs support a true 16-bit SAR ADC core with no missing codes, an 8-channel, low crosstalk multiplexer, a flexible channel sequencer, overvoltage protection clamp circuits on each analog input, on-chip oversampling and decimation, threshold detection and alert indicators, and an autonomous conversion (autocycle) mode.
The AD4697/AD4698 Easy Drive enables relax the drive requirements of the analog front end (AFE) and reference circuitry. The analog input high-Z mode and reference input high-Z mode simplifies system designs, reduce component count, and increase channel density by removing the need for dedicated high-speed ADC drivers and reference buffers. The WLCSP of the AD4698 permits an internal reference buffer, which provides an accurate, buffered reference input.
The AD4697 and AD4698 is housed in a 4.00mm × 4.00mm, 24-lead lead frame chip scale package (LFCSP), and the AD4698 is provided in a 2.960mm × 2.960mm, 36-lead wafer level chip scale package (WLCSP). All packages for the AD4697/AD4698 are specified with operation from −40°C to +125°C.
Features
- Easy Drive
- Reduced analog input and reference drive requirements
- On-chip reference buffer (WLCSP only)
- Overvoltage protection up to 5mA on each analog input
- Long acquisition phase, ≥71.5% (715ns/1000ns) of cycle time at 1MSPS
- High performance
- Sample rate: 500kSPS (AD4697) or 1MSPS (AD4698)
- INL: ±1LSB maximum
- Guaranteed 16-bit, no missing codes
- SINAD: 93dB typical, fIN = 1 kHz
- 111.2dB, OSR = 64 Oversampled dynamic range
- Small footprint, high channel density
- 24-lead, 4.00mm × 4.00mm LFCSP
- 36-lead, 2.960mm × 2.960mm WLCSP
- Easy Drive features support system-level designs with fewer components
- Enhanced digital functionality
- First conversion accurate, no latency or pipeline delay
- Fast conversion time and dual-/quad-SDO modes allow low SPI clock rates
- Customizable channel sequencer
- On-chip oversampling and decimation
- Threshold detection alerts
- Offset and gain correction
- Autonomous conversion (autocycle) mode
- 1.14V to 1.98V logic SPI
- Low power
- 8mW at fS = 1MSPS and 4mW at fS = 500kSPS
- 4µW standby power dissipation with the internal LDO disabled
- Internal LDO enables 3.15V to 5.5V, single analog supply operation
- -40°C to +125°C Wide operating temperature range
Applications
- Photodiode monitoring
- Medical instrumentation
- Vital signs monitoring
- Electronic test and measurement
- Automated test equipment
- Instrumentation and process control
- Battery-powered equipment
Functional Block Diagram
