Analog Devices Inc. AD7476SRTZ-REEL7

Overview

AD7476SRTZ-REEL7 from Analog Devices is a 12-bit, 1 MSPS successive-approximation ADC in a 6-lead SOT-23 package, operating from 2.35 V to 5.25 V supply. It delivers 70 dB SNR at 100 kHz input, features no pipeline delay, and uses an internal VDD-referenced analog input range (0 V to VDD) for maximum dynamic range in space-constrained data acquisition systems.

For engineers reviewing the AD7476SRTZ-REEL7 datasheet, AD7476SRTZ-REEL7 pinout, AD7476SRTZ-REEL7 application, or AD7476SRTZ-REEL7 equivalent, this page provides verified technical context, real-world timing behavior, confirmed power-performance trade-offs at 1 MSPS and 600 kSPS, and validated alternative options for battery-powered instrumentation and portable medical devices.

Technical Context

The AD7476SRTZ-REEL7 implements a standard SAR architecture with precise sampling controlled by the CS falling edge and conversion clocked by SCLK. Its track-and-hold amplifier supports full-power bandwidth up to 6.5 MHz and acquires within 500 ns after a full-scale step.

It uses VDD as its reference source, eliminating external reference components while maintaining 0 V to VDD input range. Serial interface timing is strictly defined: conversion requires exactly 16 SCLK cycles, data is output MSB-first with four leading zeros, and SDATA enters high-impedance state within 25 ns of SCLK falling edge.

Key Specifications

Pinout & Package

AD7476SRTZ-REEL7 is housed in a Pb-free, RoHS-compliant 6-lead SOT-23 package (JEDEC MO-178AA), with 0.95 mm pitch and 2.9 mm × 1.6 mm footprint. Thermal resistance θ_JA = 230°C/W enables operation in compact PCB layouts without forced airflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822IDR and MAX1116EUT+T, AD7476SRTZ-REEL7 uniquely combines 12-bit precision, 1 MSPS speed, VDD-referenced operation, and true 6-lead SOT-23 packaging - enabling higher-resolution sensing in smallest-area, lowest-voltage, and most power-sensitive applications.

Availability

AD7476SRTZ-REEL7 is available at Aetrix Electronics and suitable for portable medical instruments, battery-powered data loggers, optical sensor interfaces, and industrial field transmitters requiring stable component supply and long-term production continuity.

Supply support for AD7476SRTZ-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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD7476/AD7477/AD7478 family was designed specifically for space- and power-constrained data acquisition in portable and battery-operated systems, emphasizing minimal external components and guaranteed performance across extended temperature ranges.

FAQ

What is the maximum sampling frequency supported by the AD7476SRTZ-REEL7?

The AD7476SRTZ-REEL7 supports a maximum throughput rate of 1 MSPS in its A version configuration. This is achieved with a 20 MHz SCLK and VDD between 2.7 V and 5.25 V. At lower supply voltages (2.35 V to 3.6 V), the B and S versions are rated for 600 kSPS maximum, requiring 12 MHz SCLK. The conversion time is fixed at 16 SCLK cycles, so actual sample rate depends directly on clock frequency and supply conditions.

Does the AD7476SRTZ-REEL7 require an external voltage reference?

No, the AD7476SRTZ-REEL7 does not require an external voltage reference. It uses the VDD supply as its internal reference, establishing a 0 V to VDD analog input range. This eliminates the need for external reference components, reduces BOM cost, and simplifies layout - especially valuable in compact, low-power designs. However, VDD noise directly impacts ADC accuracy, so proper bypassing (e.g., 100 nF ceramic capacitor close to VDD pin) is essential.

What are the absolute maximum ratings for the analog input voltage of the AD7476SRTZ-REEL7?

The absolute maximum analog input voltage for the AD7476SRTZ-REEL7 is −0.3 V to VDD + 0.3 V. Exceeding this range risks permanent damage. Under normal operation, the specified input range is 0 V to VDD. For example, with VDD = 3.3 V, the safe operating input is 0–3.3 V; applying 3.6 V would exceed the absolute maximum and could trigger latch-up or degrade reliability. Always ensure input signals remain within these limits, especially during power sequencing or fault conditions.

How does the AD7476SRTZ-REEL7 handle power-down mode, and what is its typical current draw?

The AD7476SRTZ-REEL7 enters full power-down mode when SCLK is held inactive and CS remains high. In this state, it draws ≤1 μA maximum (typical 80 μA with SCLK active). Recovery time from power-down is 1 μs typical. This ultra-low standby current makes the AD7476SRTZ-REEL7 ideal for duty-cycled applications like wireless sensor nodes, where the ADC sleeps between measurement bursts. Power-down is fully transparent to the host controller - no register writes are needed.

Is the AD7476SRTZ-REEL7 pin-compatible with other members of the AD7476/AD7477/AD7478 family?

Yes, the AD7476SRTZ-REEL7 is pin-compatible with AD7477 and AD7478 variants in the same SOT-23-6 package. All share identical pinout (VDD, GND, VIN, SCLK, SDATA, CS), identical timing interface, and identical power requirements. This allows direct substitution in designs targeting different resolution/speed/power trade-offs - for example, upgrading from AD7478 (8-bit) to AD7476SRTZ-REEL7 (12-bit) without PCB revision, provided layout accommodates the slightly tighter SNR and noise floor requirements.