Analog Devices Inc. AD7475AR

Overview

AD7475AR from Analog Devices is a 12-bit, single-supply successive-approximation ADC with 1 MSPS throughput, 68 dB SINAD at 300 kHz, ±1.5 LSB INL (A-grade), and operation from 2.7 V to 5.25 V. It features an external 2.5 V reference input (REF IN), no pipeline delay, and is used in portable instrumentation and battery-powered data acquisition where precision, speed, and low power coexist.

For engineers reviewing the AD7475AR datasheet, AD7475AR pinout, AD7475AR application, or AD7475AR equivalent, key selection criteria include its 1 MSPS conversion rate with 4.5 mW power at 3 V, VDRIVE-independent serial interface compatibility with 3 V/5 V processors, and guaranteed no missing codes over full 12-bit range.

Technical Context

The AD7475AR implements a capacitive DAC-based successive-approximation architecture with on-chip track-and-hold, sampling on the falling edge of CS and completing conversion in exactly 16 SCLK cycles. Its analog input range is strictly 0 V to REF IN (2.5 V ±1%), and it requires no external reference buffer.

It supports three operating modes-normal, partial power-down (450 µA typ), and full power-down (1 µA max)-with power scaling directly tied to SCLK frequency and throughput demand. The VDRIVE pin decouples logic-level voltage (2.7 V–5.25 V) from VDD, enabling direct interfacing to mixed-voltage microcontrollers without level shifters.

Key Specifications

Pinout & Package

AD7475AR is housed in an 8-lead MSOP package (3.0 mm × 3.0 mm, 0.65 mm pitch), optimized for space-constrained PCB layouts in portable and embedded systems.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7475AR, AD7476AR offers higher speed at modest power increase and full pin compatibility, while ADS7822U trades speed and flexibility (no VDRIVE, internal ref) for integration simplicity and lower unit cost in less demanding roles.

Availability

AD7475AR is available at Aetrix Electronics and suitable for battery-powered systems, portable medical instruments, and industrial data acquisition requiring stable component supply, long-lifecycle support, and guaranteed traceable sourcing.

Supply support for AD7475AR 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 communications markets.

The AD7475AR belongs to Analog Devices' precision SAR ADC product line, engineered for ultra-low-power, high-throughput digitization in space- and energy-constrained embedded systems.

FAQ

What is the maximum sampling rate supported by the AD7475AR?

The AD7475AR supports a maximum throughput rate of 1 MSPS, achieved with a 20 MHz SCLK and 16-cycle conversion timing. This rate is fully specified across the −40°C to +85°C temperature range and holds for both A- and B-grade versions. At lower SCLK frequencies, throughput scales linearly, enabling flexible trade-offs between speed and power consumption in the AD7475AR design.

Does the AD7475AR include an internal voltage reference?

No, the AD7475AR does not include an internal voltage reference. It requires an external 2.5 V ±1% reference applied to the REF IN pin, with a minimum 0.1 µF decoupling capacitor. This distinguishes it from the AD7495, which integrates a 2.5 V reference and exposes it via REF OUT. The AD7475AR's external reference architecture allows system-level optimization of reference accuracy, temperature drift, and noise performance.

How does the VDRIVE pin function in the AD7475AR?

The VDRIVE pin on the AD7475AR sets the logic voltage thresholds for CS, SCLK, and SDATA independently of VDD. It accepts 2.7 V to 5.25 V and defines VINH (VDRIVE − 1 V min) and VINL (0.4 V max), allowing direct connection to 3 V or 5 V microprocessors without level shifters. This feature maintains timing integrity and simplifies interface design in mixed-voltage systems using the AD7475AR.

What power-saving modes does the AD7475AR support?

The AD7475AR supports three power-saving modes: normal (1.5 mA max at 3 V), partial power-down (100 µA max static), and full power-down (1 µA max). These modes are controlled via the serial interface and reduce current draw during idle periods without compromising wake-up latency. In full shutdown, the AD7475AR retains full functionality upon exit, with power-up time specified at 20 µs.

Is the AD7475AR pin-compatible with other members of the AD7475/AD7495 family?

Yes, the AD7475AR shares identical 8-lead MSOP and SOIC footprints with AD7476AR, AD7495, and AD7496. However, pin functions differ: AD7475AR uses Pin 1 as REF IN, whereas AD7495 uses Pin 1 as REF OUT. Interchangeability requires verification of reference architecture, power sequencing, and software configuration-AD7475AR cannot substitute for AD7495 without hardware modification due to this critical functional difference.