Analog Devices Inc. AD7495ARZ

Overview

AD7495ARZ from Analog Devices is a 12-bit, 1 MSPS successive-approximation ADC with integrated 2.5 V reference, single-supply operation (2.7 V to 5.25 V), and SPI-compatible serial interface. It delivers 68 dB SINAD at 300 kHz input, 1 µA standby current, and operates in 8-lead SOIC package for precision data acquisition in space-constrained systems.

For engineers reviewing the AD7495ARZ datasheet, AD7495ARZ pinout, AD7495ARZ application, or AD7495ARZ equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternative options, and supply-chain support details specific to AD7495ARZ - not generic ADCs or family-level abstractions.

Technical Context

The AD7495ARZ implements a capacitive DAC-based successive-approximation architecture with no pipeline delay, enabling deterministic sampling controlled by CS falling edge and conversion timing fully governed by SCLK frequency (up to 20 MHz). Its on-chip 2.5 V reference (±1% initial accuracy, 50 ppm/°C TC) drives the full-scale range (0 V to 2.5 V) without external components.

It features dual power domains: VDD powers analog and core logic (2.7 V–5.25 V), while VDRIVE independently sets I/O voltage (2.7 V–5.25 V), allowing direct interfacing to 3 V or 5 V microcontrollers without level shifters. Three power modes - normal (2 mA @ 3 V), partial power-down (230 µA), and full shutdown (1 µA) - are controlled via CS timing.

Key Specifications

Pinout & Package

AD7495ARZ is housed in an 8-lead SOIC package (ARZ suffix), with 1.27 mm pitch, 5.0 mm × 6.2 mm body size, and θJA = 157°C/W. Pin functions are electrically and mechanically distinct from AD7475 due to REF OUT instead of REF IN.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7475ARZ, AD7495ARZ trades slightly higher gain error and power for reference integration and simplified layout; versus ADS7822U, it delivers 4× higher speed and 3 dB better SNR at comparable supply and package - making AD7495ARZ optimal for portable, medium-bandwidth precision acquisition.

Availability

AD7495ARZ is available at Aetrix Electronics and suitable for battery-powered medical sensors, industrial process monitoring, optical sensor interfaces, and portable data acquisition requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AD7495ARZ 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, founded in 1965 and headquartered in Wilmington, MA.

The AD7495ARZ belongs to the AD7475/AD7495 family of micropower, single-supply SAR ADCs designed specifically for space-constrained, battery-operated instrumentation and sensor interface applications demanding 1 MSPS throughput with minimal external components.

FAQ

What is the reference voltage specification for AD7495ARZ?

The AD7495ARZ integrates a 2.5 V reference with initial accuracy of ±1% (2.4625 V to 2.5375 V) and a temperature coefficient of 50 ppm/°C. This reference appears on Pin 1 (REF OUT) and must be decoupled with ≥100 nF to GND. It is not intended to drive external circuitry directly - buffering is required before use elsewhere in the system. The AD7495ARZ uses this internal reference to set its 0 V to 2.5 V analog input range.

Does AD7495ARZ support true 1 MSPS continuous conversion?

Yes, AD7495ARZ achieves 1 MSPS sustained throughput when operated with a 20 MHz SCLK and proper CS timing. Conversion time is fixed at 16 SCLK cycles (800 ns @ 20 MHz), and the minimum quiet time between conversions is 100 ns. With t2 (CS-to-SCLK setup) ≥10 ns and acquisition time ≤325 ns, the full 1 MSPS rate is attainable in normal mode. The AD7495ARZ datasheet confirms this in Table 2 and Timing Example 1.

How does VDRIVE function in AD7495ARZ, and why is it important?

VDRIVE in AD7495ARZ sets the logic voltage level for all digital pins (CS, SCLK, SDATA), independent of VDD. It accepts 2.7 V to 5.25 V and defines VINH (VDRIVE − 1 V) and VOL (0.4 V). This allows AD7495ARZ to interface directly with 3 V microcontrollers while VDD runs at 5 V for analog noise margin - eliminating level shifters. This separation is critical for mixed-voltage system design and is explicitly defined in AD7495ARZ's Logic Inputs specifications.

What power modes does AD7495ARZ support, and how are they activated?

AD7495ARZ supports three power modes: normal (2.6 mA @ 5 V), partial power-down (230 µA static), and full power-down (1 µA). All are controlled via CS timing: normal mode during active CS low; partial mode when CS remains low but SCLK stops; full shutdown when CS is high for >100 ns. Power-up time from full shutdown is 650 µs. These modes are documented in the Operating Modes section of the AD7495ARZ datasheet Rev. D.

Is AD7495ARZ pin-compatible with AD7475ARZ?

AD7495ARZ and AD7475ARZ share identical 8-lead SOIC (ARZ) packaging and pinout numbering, but Pin 1 function differs: AD7495ARZ uses REF OUT, while AD7475ARZ uses REF IN. This functional difference means they are not drop-in replacements - board layout requires modification to route Pin 1 to decoupling capacitor (AD7495ARZ) versus external reference source (AD7475ARZ). Both parts maintain identical connections for Pins 2–8.