Analog Devices Inc. AD7476ABRM

Overview

AD7476ABRM from Analog Devices is a 12-bit, single-channel, successive-approximation analog-to-digital converter (ADC) in a 6-lead SC70 package, operating from 2.35 V to 5.25 V supply and delivering 1 MSPS throughput with 71 dB SNR at 100 kHz input. It features no pipeline delay, SPI/QSPI/MICROWIRE-compatible serial interface, and internal VDD-referenced conversion for 0 V to VDD analog input range-ideal for space-constrained battery-powered data acquisition.

For engineers reviewing the AD7476ABRM datasheet, AD7476ABRM pinout, AD7476ABRM application, or AD7476ABRM equivalent, key selection considerations include its 12-bit resolution with ±1.5 LSB INL (B grade), 800 ns max conversion time, 1 µA standby current, SC70 thermal impedance of 340.2°C/W, and compatibility with microprocessor/DSP serial interfaces requiring precise sampling control via CS.

Technical Context

The AD7476ABRM implements a standard successive-approximation register (SAR) architecture with integrated track-and-hold amplifier capable of >13 MHz full-power bandwidth. Sampling is triggered on the falling edge of CS, and conversion timing is fully determined by SCLK frequency-no internal clock generator or pipeline stages are used.

Its reference is derived directly from VDD, eliminating external reference components and enabling rail-to-rail analog input (0 V to VDD). The serial output delivers 12-bit MSB-first data preceded by four leading zeros, synchronized to the falling edge of SCLK, with three-state SDATA controlled by CS deassertion.

Key Specifications

Pinout & Package

AD7476ABRM is housed in a 6-lead SC70 package (2.2 mm × 1.35 mm × 0.9 mm), optimized for high-density PCB layouts and low thermal resistance (θJA = 340.2°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7476ABRM, AD7476ARMZ offers identical electrical performance in a more manufacturable package, while ADS7822U trades speed and integration for lower unit cost in non-demanding applications-making AD7476ABRM optimal for size- and speed-critical embedded sensing.

Availability

AD7476ABRM is available at Aetrix Electronics and suitable for battery-powered systems, portable medical instruments, and industrial field transmitters requiring stable component supply with guaranteed long-term sourcing.

Supply support for AD7476ABRM 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 AD7476A family was designed specifically for ultra-compact, low-power, high-speed data acquisition in portable and space-constrained embedded systems-emphasizing integration, supply flexibility, and ease of microprocessor interfacing.

FAQ

What is the maximum sampling rate supported by the AD7476ABRM?

The AD7476ABRM supports a maximum throughput rate of 1 MSPS under specified conditions (VDD = 2.35 V to 5.25 V, fSCLK = 20 MHz). Its conversion time is fixed at 800 ns (16 SCLK cycles), so actual achievable rate depends on SCLK frequency and system timing margins-including tQUIET (50 ns minimum between conversions) and acquisition time (250 ns max). At 20 MHz SCLK, the theoretical limit is sustained 1 MSPS operation.

Does the AD7476ABRM require an external voltage reference?

No, the AD7476ABRM does not require an external voltage reference. It uses an internal reference derived directly from the VDD supply, enabling a full-scale analog input range of 0 V to VDD. This simplifies design, reduces component count, and maintains dynamic range across supply variations-though absolute accuracy depends on VDD stability and tolerance.

What are the logic voltage level requirements for the AD7476ABRM digital inputs?

The AD7476ABRM digital inputs (CS, SCLK) accept logic levels compatible with its VDD supply: VINH ≥ 2.4 V (or ≥1.8 V when VDD = 2.35 V), and VINL ≤ 0.8 V (or ≤0.4 V when VDD = 3 V). Input currents are tightly bounded (±0.5 µA max on SCLK, ±10 nA typ on CS), ensuring compatibility with standard CMOS microcontrollers without level-shifting circuitry.

How does the AD7476ABRM handle power-down mode, and what is its wake-up time?

The AD7476ABRM enters full power-down mode when CS remains high for >100 ns after conversion completes, reducing IDD to 1 µA max (typically 50 nA). Wake-up is instantaneous-conversion begins on the next CS falling edge, with power-up time from full power-down specified at 1 µs max. No initialization sequence or delay is required before the first valid sample.

Can the AD7476ABRM interface directly with common microcontrollers like STM32 or MSP430?

Yes, the AD7476ABRM interfaces directly with SPI-capable microcontrollers including STM32 and MSP430. Its CS, SCLK, and SDATA signals comply with SPI Mode 0 (CPOL = 0, CPHA = 0), and it requires no additional control logic. The 12-bit result is output MSB-first with four leading zeros, matching standard SPI frame expectations-enabling seamless integration using hardware SPI peripherals or bit-banged GPIO.