Analog Devices Inc. AD7896ARZ-REEL7

Overview

AD7896ARZ-REEL7 from Analog Devices is a single-supply, 12-bit successive approximation ADC with 8 µs conversion time, integrated track-and-hold and on-chip clock, housed in an 8-lead SOIC package. It operates from 2.7 V to 5.5 V, accepts 0 V to VDD analog input, delivers 100 kHz throughput, and consumes 9 mW typical-ideal for space-constrained, low-power data acquisition in portable instrumentation.

For engineers reviewing the AD7896ARZ-REEL7 datasheet, AD7896ARZ-REEL7 pinout, AD7896ARZ-REEL7 application, or AD7896ARZ-REEL7 equivalent, key selection considerations include its 2-wire serial interface timing (10 MHz max SCLK), auto power-down mode wake-up behavior, unipolar offset error (±4 LSB max at VDD = 5 V), SNR of 70 dB min at 10 kHz input, and SOIC-8 thermal impedance (160°C/W).

Technical Context

The AD7896ARZ-REEL7 implements a laser-trimmed R-2R ladder SAR architecture with internal VDD-derived reference, eliminating external reference components. Its track-and-hold amplifier achieves 1.5 µs acquisition time and supports full-scale sine wave inputs up to 50 kHz.

It features two distinct operating modes: Mode 1 (high-speed, 8 µs conversion, BUSY asserted on falling CONVST) and Mode 2 (auto-sleep, 14 µs total cycle including 6 µs wake-up, triggered by low CONVST hold). Serial data output is straight binary, 16-bit frame (4 leading zeros + 12-bit result), clocked on SCLK falling edge with guaranteed 10 ns data hold time.

Key Specifications

Pinout & Package

AD7896ARZ-REEL7 is packaged in an 8-lead, 0.150" wide SOIC (SOIC_N) with standard JEDEC MS-012AC footprint and 160°C/W θ_JA.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and MAX11131ETE+, the AD7896ARZ-REEL7 uniquely combines 12-bit accuracy, VDD-referenced operation, auto-sleep power management, and SOIC-8 manufacturability-making it optimal for cost-sensitive, battery-operated, or space-constrained 100 kSPS applications.

Availability

AD7896ARZ-REEL7 is available at Aetrix Electronics and suitable for portable instrumentation, industrial sensor transmitters, medical vital sign monitors, and test equipment requiring stable component supply across extended temperature ranges (0°C to +70°C).

Supply support for AD7896ARZ-REEL7 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.

The AD7896ARZ-REEL7 belongs to Analog Devices' legacy precision SAR ADC product line, engineered for low-power, single-supply data acquisition in space- and energy-constrained embedded systems.

FAQ

What is the maximum serial clock frequency supported by the AD7896ARZ-REEL7?

The AD7896ARZ-REEL7 supports a maximum SCLK frequency of 10 MHz under 5 V operation. At this rate, the 16-bit serial read completes in 1.6 µs. Timing margins require SCLK high/low pulsewidth ≥402 ns and data access time ≤60 ns (5 V), so system-level setup/hold constraints must be verified against the host controller's timing budget.

Does the AD7896ARZ-REEL7 require an external voltage reference?

No, the AD7896ARZ-REEL7 does not require an external voltage reference. Its internal reference is derived directly from the VDD supply, enabling a 0 V to VDD analog input range. This simplifies design, reduces component count, and avoids reference drift errors-though system-level accuracy remains dependent on VDD stability.

How does the auto power-down mode function in the AD7896ARZ-REEL7?

In auto power-down mode (Mode 2), the AD7896ARZ-REEL7 enters low-current sleep after conversion completion (BUSY goes low) when CONVST remains low. It wakes up 6 µs after the next rising edge of CONVST, then performs an 8 µs conversion-total cycle time is 14 µs. IDD drops to 5 µA typ (2.7–3.6 V), making it ideal for infrequent sampling.

What is the analog input impedance specification for the AD7896ARZ-REEL7?

The AD7896ARZ-REEL7 specifies ±2 µA max input current across the full 0 V to VDD range. With its integrated track-and-hold, it presents high effective input impedance during acquisition-however, driving source impedance must be ≤1 kΩ to ensure 12-bit settling within the 1.5 µs acquisition time, per datasheet design guidance.

Can the AD7896ARZ-REEL7 interface directly with a microcontroller SPI peripheral?

The AD7896ARZ-REEL7 uses a 2-wire serial interface (SCLK and SDATA only) with no chip select or MOSI lines, so it is not SPI-compliant. However, it can be interfaced using GPIO bit-banging or by configuring an SPI master in 3-wire mode with unused pins ignored-ensuring SCLK timing meets t2/t3 ≥402 ns and data is sampled on the falling edge per the timing diagram.