Analog Devices Inc. AD7476ABRM-REEL

Overview

AD7476ABRM-REEL from Analog Devices is a 12-bit, single-supply, successive-approximation analog-to-digital converter (ADC) in a 6-lead SC70 package, operating from 2.35 V to 5.25 V with 1 MSPS throughput, 71 dB SNR at 100 kHz input, and no pipeline delay-designed for high-speed, low-power data acquisition in portable medical instruments and battery-powered sensor interfaces.

For engineers reviewing the AD7476ABRM-REEL datasheet, AD7476ABRM-REEL pinout, AD7476ABRM-REEL application, or AD7476ABRM-REEL equivalent, key selection considerations include its 12-bit resolution with ±1.5 LSB INL, SC70 footprint constraints, SPI-compatible serial interface timing, and VDD-referenced 0 V to VDD input range requiring careful analog signal conditioning.

Technical Context

The AD7476ABRM-REEL implements a standard successive-approximation register (SAR) architecture with integrated track-and-hold, sampling on the falling edge of CS and initiating conversion simultaneously. Its reference is derived internally from VDD, eliminating external reference components but tying full-scale range directly to supply stability.

Conversion is clocked by SCLK, requiring 16 cycles per sample (800 ns max at 20 MHz), with no latency between command and result. The device supports flexible power management via CS-controlled standby mode (1 µA max), enabling duty-cycled operation in energy-constrained systems without sacrificing timing predictability.

Key Specifications

Pinout & Package

AD7476ABRM-REEL is housed in a 6-lead SC70 package (2.2 mm × 1.35 mm, 0.95 mm height), optimized for ultra-compact PCB layouts in portable electronics. Pin assignment is fixed and non-optional per datasheet Figure 5.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and MAX1116EKA+T, AD7476ABRM-REEL uniquely combines 12-bit accuracy, 1 MSPS speed, 2.35–5.25 V operation, SC70 packaging, and VDD-referenced input-making it the sole option meeting all four criteria simultaneously for compact, wide-supply, high-fidelity data acquisition.

Availability

AD7476ABRM-REEL is available at Aetrix Electronics and suitable for portable medical sensors, battery-powered data loggers, and industrial motor current monitoring requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AD7476ABRM-REEL 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, serving precision instrumentation, industrial automation, and healthcare markets since 1965.

The AD7476A family was designed specifically to deliver 12-/10-/8-bit SAR ADC performance in the smallest possible footprint for space-constrained, battery-sensitive applications-prioritizing low power, supply flexibility, and ease of digital interfacing.

FAQ

What is the maximum sampling rate supported by the AD7476ABRM-REEL?

The AD7476ABRM-REEL supports a maximum throughput rate of 1 MSPS, achieved with a 20 MHz SCLK and 16-cycle conversion sequence. At lower SCLK frequencies, the effective sampling rate scales linearly-for example, 5 MHz SCLK yields ~315 kSPS. This rate is guaranteed across the full –40°C to +85°C operating range and 2.35 V to 5.25 V supply.

Does the AD7476ABRM-REEL require an external voltage reference?

No, the AD7476ABRM-REEL uses an internal reference derived from VDD, resulting in an analog input range of 0 V to VDD. This eliminates the need for external reference components and simplifies layout, though it means full-scale accuracy depends directly on VDD stability and ripple-designers must ensure <10 mV p-p supply noise for optimal 12-bit performance.

What is the purpose of the four leading zeros in the AD7476ABRM-REEL serial data stream?

The AD7476ABRM-REEL outputs four leading zeros followed by the 12-bit conversion result MSB-first. These zeros provide timing alignment and bus settling time, ensuring reliable capture by host processors with variable setup/hold margins. They are fixed and present in every frame regardless of input value, and must be stripped in firmware to extract the valid 12-bit word.

How does the AD7476ABRM-REEL handle power-down mode entry and exit?

The AD7476ABRM-REEL enters full power-down mode when CS remains high for >100 ns after conversion completes, drawing ≤1 µA. Wake-up occurs on the next CS falling edge, with 1 µs maximum power-up time before valid conversion. During this interval, the track-and-hold amplifier reacquires the VIN signal, requiring ≥250 ns acquisition time before sampling.

Is the AD7476ABRM-REEL pin-compatible with other members of the AD7476A/AD7477A/AD7478A family?

Yes, the AD7476ABRM-REEL shares identical 6-lead SC70 pinout and interface protocol with AD7477A and AD7478A variants. However, resolution (12 vs. 10 vs. 8 bits), dynamic performance (71 dB vs. 61 dB vs. 49 dB SNR), and conversion time (800 ns vs. 700 ns vs. 600 ns) differ-firmware must be adapted to parse the correct number of significant bits from the serial stream.