Analog Devices Inc. AD7686BRMZ

Overview

AD7686BRMZ from Analog Devices is a 16-bit, charge redistribution successive approximation ADC with no missing codes, 500 kSPS throughput, ±2 LSB max INL, 92.5 dB SINAD at 20 kHz, and pseudo-differential 0 V to VREF input range-designed for high-precision data acquisition in battery-powered instrumentation and medical instruments.

For engineers reviewing the AD7686BRMZ datasheet, AD7686BRMZ pinout, AD7686BRMZ application, or AD7686BRMZ equivalent, this page delivers verified specifications, validated pin functions, real-world use cases in process control and portable diagnostics, and confirmed drop-in alternatives for design continuity.

Technical Context

The AD7686BRMZ implements a single-supply 5 V successive approximation architecture with on-chip track-and-hold, zero pipeline delay, and internal conversion clock-enabling immediate result availability after CNV rising edge. Its differential sampling structure rejects common-mode noise while supporting true 16-bit linearity across −40°C to +85°C.

It features a proprietary SPI-/QSPI™-/MICROWIRE™-/DSP-compatible serial interface with daisy-chain capability and busy indicator, plus dual supply operation: VDD (4.5–5.5 V) for analog core and VIO (1.8–5 V) for logic compatibility-allowing seamless integration with mixed-voltage microcontrollers.

Key Specifications

Pinout & Package

AD7686BRMZ is housed in a 10-lead MSOP package (3 mm × 3 mm, 0.85 mm height) with exposed pad connected to GND for thermal stability. Pin numbering follows standard MSOP top-view orientation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit SAR ADC applications.

Compared with AD7685BRMZ, AD7686BRMZ delivers 100 kSPS higher throughput and 1.5 dB better SINAD at same power; versus AD7980BRMZ, it offers pin compatibility and VIO flexibility but trades off 500 kSPS speed-making AD7686BRMZ optimal for upgrade paths in existing MSOP-based designs.

Availability

AD7686BRMZ is available at Aetrix Electronics and suitable for battery-powered equipment, medical instruments, process controls, and portable test equipment requiring stable component supply and long-term production continuity.

Supply support for AD7686BRMZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA, with R&D centers worldwide.

The AD7686BRMZ belongs to Analog Devices' PulSAR® family of precision SAR ADCs-engineered specifically for high-resolution, low-power, zero-latency data acquisition in portable and industrial instrumentation.

FAQ

What is the maximum recommended reference voltage for AD7686BRMZ?

The AD7686BRMZ supports an external reference voltage from 0.5 V up to VDD (max 5.5 V). When VDD = 5 V, REF may be set to 5 V for full 0–5 V input range; however, using a precision 4.096 V or 5.0 V reference (e.g., ADR4550) is recommended to maximize SNR and minimize gain error drift. The device draws only 100 µA from REF at 500 kSPS, enabling low-noise buffered reference designs.

Does AD7686BRMZ require an external driver amplifier?

AD7686BRMZ does not require an external driver amplifier for low-impedance sources (<100 Ω), as its on-chip track-and-hold handles acquisition directly. However, for high-impedance sensors or anti-alias filtering, Analog Devices recommends ADA4941-1 or AD8675-both optimized for driving the 30 pF sampling capacitor and 600 Ω series resistance without degrading THD or settling time. Driver selection depends on source impedance and required bandwidth.

Can AD7686BRMZ operate with a 3.3 V digital interface while using 5 V analog supply?

Yes-AD7686BRMZ supports independent analog and digital supplies: VDD = 5 V powers the SAR core and track-and-hold, while VIO = 3.3 V sets logic thresholds for SDI, SCK, SDO, and CNV. This configuration is explicitly validated in the datasheet and enables direct connection to 3.3 V microcontrollers without level shifters, preserving timing margins and reducing system complexity.

Is AD7686BRMZ pin-compatible with other PulSAR ADCs?

Yes-AD7686BRMZ is pin-for-pin compatible with AD7685BRMZ, AD7687BRMZ, and AD7688BRMZ in the 10-lead MSOP package. All share identical pin functions, electrical characteristics, and serial interface behavior, allowing drop-in upgrades for higher throughput (AD7686BRMZ) or lower cost (AD7685BRMZ) without PCB changes.

What is the aperture delay specification for AD7686BRMZ?

The aperture delay for AD7686BRMZ is 2.5 ns (typical) at VDD = 5 V, defined as the time between the CNV rising edge and the instant the input signal is held for conversion. This low, tightly specified delay minimizes sampling uncertainty and supports accurate time-domain measurements-critical for phase-sensitive applications like power quality analyzers and motor control encoders.