Блог компании The Premier Choice for Industrial Control and Medical Equipment: ADI AD7689 16-bit, 8-channel, 250 kSPS SAR ADC

The AD7689 supplied by Mingjiada Electronics is a high-performance, 16-bit, 8-channel, 250 kSPS PulSAR® successive approximation register (SAR) analogue-to-digital converter (ADC) developed by Analog Devices (ADI).

AD7689 Product Overview

The AD7689 is a highly integrated data acquisition chip that combines a high-performance ADC with a variety of signal chain components on a single chip:

Core Architecture: Utilises a charge-redistribution SAR architecture, ensuring zero pipelining delay and high-precision 16-bit conversion with no lost counts.

Analogue Front End: Features an on-chip 8-channel low-crosstalk multiplexer, which can be flexibly configured for single-ended (with or without ground sense), differential or pseudo-bipolar input modes.

Internal Integration: The device incorporates an optional low-drift reference voltage source (2.5 V or 4.096 V), a temperature sensor and an optional single-pole filter.

Control and Communication: An on-board channel timing controller enables automatic continuous scanning of multiple channels. The communication interface is SPI, compatible with MICROWIRE, QSPI and DSP.

Specifications

The following is a summary of the AD7689’s key technical specifications:

Resolution: 16-bit

Number of Channels: 8 channels (multiplexer inputs)

Sampling Rate: 250 kSPS (thousand samples per second)

Architecture: SAR (Successive Approximation Register)

Integral Non-Linearity (INL): Typical ±0.4 LSB; Maximum ±1.5 LSB

Dynamic Range: 93.8 dB

Signal-to-Noise-to-Distortion Ratio (SINAD) @20 kHz input: 92.5 dB

Total Harmonic Distortion (THD) @20 kHz input: -100 dB

Analogue input range: 0 V to VREF (VREF up to VDD)

Reference voltage source: Internally selectable (2.5 V/4.096 V) or externally supplied

Supply voltage (VDD): 2.3 V to 5.5 V

Logic interface voltage (VIO): 1.8 V to VDD

Power consumption: 12.5 mW at 5 V/250 kSPS; standby current 50 nA

Operating temperature range: –40 °C to +85 °C (some models support up to +125 °C)

Package: 20-pin LFCSP (4 mm × 4 mm) or WLCSP (2.4 mm × 2.4 mm)

AD7689 Key Features

Balance of high precision and low power consumption: Delivers 16-bit high precision at a sampling rate of 250 kSPS whilst maintaining extremely low power consumption, making it ideal for battery-powered or energy-sensitive devices.

Highly integrated for simplified design: The on-chip integration of a reference source, temperature sensor, channel sequencer and programmable filter significantly reduces the number of external components and simplifies PCB design.

Flexible input configuration: Eight analogue input channels can be independently configured for single-ended, differential or pseudo-bipolar modes, accommodating a wide variety of sensor signals.

Convenient digital interface: A wide-voltage-range SPI serial interface facilitates connection to a variety of mainstream microcontrollers (MCUs) and digital signal processors (DSPs).

Typical Applications

Owing to its outstanding performance and high level of integration, the AD7689 is widely used across multiple sectors:

Industrial and process control: Multi-channel system monitoring, power line monitoring, and data acquisition in factory automation.

Medical Equipment: High-precision acquisition of physiological signals such as electrocardiograms (ECG/EKG) and electroencephalograms (EEG).

Test and Measurement: High-precision data acquisition systems and seismic data acquisition systems.

Communications and Consumer Electronics: Mobile communication devices (GPS), battery-powered portable instruments and wearable health monitoring devices.

About Mingjiada Electronics

Shenzhen Mingjiada Electronics Co., Ltd. is a specialist distributor of electronic components with over 20 years’ industry experience. Mingjiada has long supplied a full range of ADI products, including data converters, amplifiers and processors, and offers them from stock.

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