Analog Devices Inc. AD7683BRMZ

Overview

AD7683BRMZ from Analog Devices is a 16-bit, 100 kSPS, pseudo-differential successive approximation ADC with ±1 LSB typical INL, SPI-compatible serial interface, and single-supply operation from 2.7 V to 5.5 V. It integrates an on-chip track-and-hold, supports external reference up to VDD, and targets precision data acquisition in space-constrained battery-powered systems.

For engineers reviewing the AD7683BRMZ datasheet, AD7683BRMZ pinout, AD7683BRMZ application, or AD7683BRMZ equivalent, key selection considerations include its 8-lead MSOP/QFN package, 1 nA standby current, 150 µW power at 10 kSPS/2.7 V, ±3 LSB max INL over temperature, and compatibility with SPI/QSPI/MICROWIRE/DSP controllers.

Technical Context

The AD7683BRMZ uses a charge redistribution SAR architecture with a built-in track-and-hold, delivering no missing codes (B grade) and zero pipeline latency. Its pseudo-differential input accepts 0 V to VREF across +IN and –IN, referenced to remote ground sense, enabling rejection of common-mode noise in sensor interfaces.

Conversion is initiated by the CS falling edge, synchronized to an external DCLOCK up to 2.9 MHz; it outputs 16-bit straight-binary data on DOUT with timing-critical setup/hold windows (tSUCS = 20 ns, tHDO = 5–16 ns). Power scales linearly with throughput-enabling ultra-low-power operation at reduced sampling rates.

Key Specifications

Pinout & Package

AD7683BRMZ is available in an 8-lead MSOP (3 mm × 3 mm) and an 8-lead QFN (LFCSP, 3 mm × 3 mm, SOT-23 footprint) with exposed pad (EPAD) connected to GND. Both packages support −40°C to +85°C operation and share identical pin functions.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7683BRMZ, AD7685BRMZ offers superior speed and linearity in identical packaging, while ADS8325IPW demands different power and interface architecture-making AD7683BRMZ optimal for new low-power, SPI-based designs prioritizing integration and simplicity.

Availability

AD7683BRMZ is available at Aetrix Electronics and suitable for battery-powered equipment, medical instruments, process control systems, and portable test equipment requiring stable component supply across extended product lifecycles.

Supply support for AD7683BRMZ 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.

The AD7683BRMZ belongs to the PulSAR® family of precision SAR ADCs designed specifically for low-power, high-accuracy data acquisition in space- and energy-constrained applications-from portable diagnostics to industrial IoT endpoints.

FAQ

What is the maximum clock frequency supported by the AD7683BRMZ digital interface?

The AD7683BRMZ accepts a DCLOCK input up to 2.9 MHz, enabling full 16-bit data transfer within its 10 µs conversion cycle. This timing aligns with standard SPI peripherals operating at ≤2.9 MHz, and the device remains functional even with clock gating for variable sampling rates. The AD7683BRMZ does not require continuous clocking between conversions, supporting burst-mode operation to minimize system power.

Does the AD7683BRMZ require an external reference voltage, and what are the acceptable ranges?

Yes, the AD7683BRMZ requires an external reference applied to the REF pin, which accepts voltages from 0.5 V to VDD (2.7 V to 5.5 V). The reference must be low-impedance and decoupled with a 2.2–10 µF ceramic capacitor directly to GND. Using VDD as reference simplifies design but limits dynamic range; dedicated references like ADR435 improve accuracy and temperature stability for metrology-grade applications.

How does the AD7683BRMZ achieve ultra-low power consumption in battery-operated systems?

The AD7683BRMZ achieves ultra-low power by powering down automatically between conversions, scaling current linearly with throughput: 150 µW at 10 kSPS/2.7 V, 1.5 mW at 100 kSPS/2.7 V, and 4 mW at 100 kSPS/5 V. Its 1 nA standby current during idle periods allows deep-sleep modes in microcontroller-based systems. No external shutdown sequencing is needed-the CS pin controls all power states.

Can the AD7683BRMZ interface directly with a microcontroller's SPI peripheral without level-shifting?

Yes, the AD7683BRMZ supports standard SPI logic levels: VIH = 0.7 × VDD and VIL = 0.3 × VDD, with input thresholds tracking the supply. When powered from 3.3 V, it interfaces seamlessly with 3.3 V microcontrollers; at 2.7 V, it remains compatible with most 2.7–3.6 V I/O domains. No level shifters are required as long as the host MCU's VIO matches AD7683BRMZ's VDD within tolerance.

What is the significance of the –IN pin in the AD7683BRMZ pseudo-differential architecture?

Unlike single-ended ADCs, the –IN pin in the AD7683BRMZ provides a dedicated analog ground sense point-enabling remote Kelvin sensing to eliminate voltage drops across PCB traces or cables. This improves dc accuracy in distributed sensor systems and rejects common-mode noise when +IN and –IN share interference sources. It is not a true differential input but delivers significant noise immunity with simpler drive requirements than fully differential front-ends.