Analog Devices Inc. AD7876BRZ

Overview

AD7876BRZ from Analog Devices is a complete monolithic 12-bit successive approximation ADC with integrated track-and-hold amplifier, laser-trimmed internal clock, and on-chip 3 V buried Zener reference. It supports ±10 V bipolar analog input range, achieves 8 μs conversion time with external 2.5 MHz clock, and delivers 57 ns parallel data access time. Designed for precision data acquisition in industrial instrumentation and test equipment.

For engineers reviewing the AD7876BRZ datasheet, AD7876BRZ pinout, AD7876BRZ application, or AD7876BRZ equivalent, this page provides verified technical context, real-world interface timing constraints, confirmed SOIC-24 package mapping, and two validated alternative parts with documented functional and application-level differences.

Technical Context

The AD7876BRZ implements a SAR architecture with internal 3 V reference and 2 μs track-and-hold acquisition. Its analog front-end uses resistor-scaling networks (2.1R/7R/3R) to support ±10 V input range while maintaining 12-bit linearity and twos-complement output coding.

Digital interface flexibility includes three modes: 12-bit parallel (DB0–DB11), two-byte parallel (HBEN-controlled), and serial (SCLK/SSTRB/SDATA). Control logic responds asynchronously to CONVST rising edge or CS falling edge, enabling standalone or microprocessor-synchronized operation without external timing components.

Key Specifications

Pinout & Package

AD7876BRZ is housed in a 24-pin small outline integrated circuit (SOIC) package with standard 0.3-inch body width and 0.050-inch lead pitch. Pin 1 identifier is marked by a notch or dot; pins are numbered counterclockwise from top-left corner when viewed from top.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit SAR ADC applications.

Compared with AD7875BRZ and AD7870BNZ, the AD7876BRZ uniquely supports ±10 V bipolar inputs in an SOIC-24 package, making it the only option among the three for high-dynamic-range industrial signal acquisition without external level-shifting circuitry.

Availability

AD7876BRZ is available at Aetrix Electronics and suitable for industrial process monitoring, automated test equipment, power quality analysis, and medical diagnostic instrumentation requiring stable component supply and long-term design continuity.

Supply support for AD7876BRZ 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA, with decades of expertise in precision data conversion and signal conditioning.

The AD787x family was designed specifically for high-accuracy, medium-speed data acquisition in industrial and instrumentation applications where integration, dc accuracy, and interface flexibility are critical.

FAQ

What is the maximum analog input frequency supported by the AD7876BRZ?

The AD7876BRZ can accurately convert full-power signals up to 50 kHz while maintaining 12-bit accuracy. Its track-and-hold amplifier has a 0.1 dB cutoff typically at 500 kHz, allowing faithful digitization of band-limited industrial sensor outputs without aliasing when sampled at 100 kHz. The AD7876BRZ specification explicitly confirms this 50 kHz full-power bandwidth limit under dynamic conditions.

Does the AD7876BRZ require external clock components?

No, the AD7876BRZ does not require external clock components. It features an on-chip laser-trimmed clock oscillator that guarantees accurate conversion timing; tying the CLK pin to VSS activates this internal clock. An external 2.5 MHz TTL-compatible clock may be applied if tighter system-level synchronization is needed, but it is optional - the AD7876BRZ operates fully autonomously with internal timing.

How is the ±10 V input range implemented in the AD7876BRZ?

The AD7876BRZ implements its ±10 V input range using an internal resistor-scaling network (2.1R/7R/3R) shown in Figure 9 of the datasheet. This network attenuates the ±10 V input to match the internal 3 V reference range of the 12-bit DAC core, preserving full-scale resolution. Input impedance is typically 33 kΩ, and the output code is twos-complement binary with 1 LSB = 4.88 mV (20 V / 4096).

Can the AD7876BRZ operate with only a +5 V supply?

No, the AD7876BRZ requires dual ±5 V supplies: VDD = +5 V ±5% and VSS = −5 V ±5%. The analog front-end, including the track-and-hold amplifier and internal reference circuitry, depends on the negative rail for proper bipolar signal handling. Operating with only +5 V would violate absolute maximum ratings and prevent correct conversion of negative input voltages - the AD7876BRZ specification mandates both rails for specified performance.

What is the purpose of the 12/8/CLK pin on the AD7876BRZ?

The 12/8/CLK pin on the AD7876BRZ selects the digital interface mode and serial clock behavior: +5 V configures 12-bit parallel-only output; 0 V enables byte or serial mode with gated SCLK; −5 V enables byte or serial mode with continuous SCLK. This single pin determines data format, HBEN functionality, and SCLK timing - eliminating need for separate mode-control lines and simplifying microcontroller GPIO usage.