Analog Devices Inc. AD7796BRUZ

Overview

AD7796BRUZ from Analog Devices is a low-power, 16-bit sigma-delta ADC optimized for bridge sensor signal conditioning in precision weigh scales and strain gage systems. It integrates a fixed-gain (×128) instrumentation amplifier, on-chip temperature sensor (±2°C accuracy), internal 64 kHz clock oscillator, and simultaneous 50 Hz/60 Hz rejection - enabling direct connection to mV-level bridge outputs without external amplification or filtering.

For engineers reviewing the AD7796BRUZ datasheet, AD7796BRUZ pinout, AD7796BRUZ application, or AD7796BRUZ equivalent, key selection criteria include its 250 µA typical supply current, 4.17–123 Hz software-programmable update rate, 65 nV RMS noise at 4.17 Hz, 16-lead TSSOP package with independent AVDD/DVDD supplies, and SPI/QSPI/MICROWIRE-compatible 3-wire serial interface.

Technical Context

The AD7796BRUZ implements a fully integrated analog front end centered on a 16-bit Σ-Δ modulator with sinc3 digital filter, supporting bipolar input ranges referenced to ±V_REF/128. Its on-chip instrumentation amplifier provides fixed ×128 gain with ±1 µV typical offset error and ±10 nV/°C drift, eliminating external gain stages for bridge sensors.

Simultaneous 50 Hz and 60 Hz rejection is achieved via programmable notch filters synchronized to the internal or external 64 kHz clock; rejection exceeds 80 dB at both frequencies when configured with FS[3:0] = 1010. The device supports independent analog (AVDD: 2.7–5.25 V) and digital (DVDD: 2.7–5.25 V) supplies, enabling mixed-voltage system interfacing.

Key Specifications

Pinout & Package

AD7796BRUZ is housed in a 16-lead TSSOP (Thin Shrink Small Outline Package) with 0.65 mm lead pitch, RoHS-compliant, and rated for –40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision sigma-delta ADC applications.

Compared with AD7795BRUZ and ADS124S08IPW, the AD7796BRUZ delivers optimal balance of 16-bit precision, ultra-low power (250 µA), and minimal BOM count for dedicated bridge sensor applications - avoiding unnecessary complexity or cost where 24-bit resolution is not required.

Availability

AD7796BRUZ is available at Aetrix Electronics and suitable for weigh scales, strain gage systems, and portable instrumentation requiring stable component supply, long-term lifecycle support, and traceable sourcing for medical, industrial, and test equipment programs.

Supply support for AD7796BRUZ 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 design centers worldwide.

The AD7796BRUZ belongs to Analog Devices' precision sigma-delta ADC product line, engineered specifically for low-power, high-accuracy bridge sensor measurement in industrial and instrumentation applications - emphasizing integration, noise performance, and ease of calibration.

FAQ

What is the maximum update rate supported by the AD7796BRUZ?

The AD7796BRUZ supports a software-programmable output update rate ranging from 4.17 Hz to 123 Hz. At the highest rate (123 Hz), RMS noise increases to 430 nV, trading resolution for speed. This range is selected via the FS[3:0] bits in the mode register and applies with either internal or external 64 kHz clock sources. The AD7796BRUZ maintains 16-bit no-missing-codes performance across the entire range.

Does the AD7796BRUZ require an external reference voltage?

No, the AD7796BRUZ does not require an external reference, but it is designed to operate with one. It accepts an external reference voltage between 0.1 V and AVDD applied across REFIN(+) and REFIN(−), with 2.5 V being the nominal value. The device also functions correctly with AVDD used directly as the reference (ratiometric mode), though this reduces effective resolution due to AVDD noise and drift. The AD7796BRUZ itself contains no internal reference voltage source.

Can the AD7796BRUZ perform simultaneous 50 Hz and 60 Hz rejection?

Yes, the AD7796BRUZ achieves simultaneous 50 Hz and 60 Hz rejection through its programmable sinc3 digital filter synchronized to the internal or external 64 kHz clock. When configured with FS[3:0] = 1010, it delivers ≥80 dB rejection at both frequencies. This capability is hardware-implemented and requires no firmware intervention, making it ideal for global instrumentation deployed in regions with either 50 Hz or 60 Hz mains infrastructure.

What is the purpose of the DOUT/RDY pin on the AD7796BRUZ?

The DOUT/RDY pin on the AD7796BRUZ serves two distinct functions: it outputs serial conversion data (DOUT) and asserts a logic-low signal when a new conversion result is ready (RDY). As an RDY indicator, it can trigger a microcontroller interrupt to initiate data readback. As a DOUT pin, it shifts out 16-bit conversion results on the SCLK falling edge. This dual functionality reduces pin count and simplifies interface timing compared to separate data and status lines.

Is the AD7796BRUZ pin-compatible with the AD7797BRUZ?

Yes, the AD7796BRUZ and AD7797BRUZ share identical 16-lead TSSOP packaging, pinout, register map, and interface protocol. The primary difference is resolution: AD7796BRUZ is specified for 16-bit no-missing-codes performance, while AD7797BRUZ guarantees 24-bit resolution. Both devices use the same communication, mode, and configuration registers, allowing hardware design reuse - only firmware calibration and noise budgeting differ between the two variants.