Analog Devices Inc. AD7478AAKSZ-REEL7

Overview

AD7478AAKSZ-REEL7 from Analog Devices is an 8-bit, 1.2 MSPS successive-approximation ADC operating from a single 2.35 V to 5.25 V supply, featuring 600 ns conversion time, 13.5 MHz full-power bandwidth, and SPI/QSPI/MICROWIRE/DSP-compatible serial interface. It delivers ±0.3 LSB integral nonlinearity and 49 dB SINAD at 100 kHz input, targeting space-constrained data acquisition in battery-powered instrumentation.

For engineers reviewing the AD7478AAKSZ-REEL7 datasheet, AD7478AAKSZ-REEL7 pinout, AD7478AAKSZ-REEL7 application, or AD7478AAKSZ-REEL7 equivalent, key selection criteria include its SC70-6 package footprint, 12-cycle SCLK serial timing, internal VDD-referenced 0 V to VDD analog input range, and 1 µA standby current-critical for low-power embedded sensing and portable medical devices.

Technical Context

The AD7478AAKSZ-REEL7 implements a standard successive-approximation register (SAR) architecture with no pipeline delay, sampling on the falling edge of CS and initiating conversion simultaneously. Its track-and-hold amplifier supports up to 13.5 MHz input signals and achieves 225 ns acquisition time.

Conversion timing is fully synchronous to the external SCLK: 12 cycles required at up to 20 MHz, enabling deterministic latency and flexible throughput scaling. The device uses straight binary coding, references directly to VDD, and features three-state SDATA output with 36 ns bus relinquish time.

Key Specifications

Pinout & Package

AD7478AAKSZ-REEL7 is housed in a 6-lead SC70 package (2.0 mm × 1.25 mm, 0.5 mm pitch), optimized for high-density routing and thermal performance in portable systems.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit SAR ADC applications.

Compared with ADS7822IDR and MAX11100ETE+, the AD7478AAKSZ-REEL7 uniquely combines 1.2 MSPS speed, ultra-small SC70-6 footprint, VDD-referenced input, and 1 µA standby in a single 2.35–5.25 V supply-making it optimal for miniaturized, multi-rail, battery-sensitive systems where layout area and power budget are primary constraints.

Availability

AD7478AAKSZ-REEL7 is available at Aetrix Electronics and suitable for battery-powered instrumentation, portable medical sensors, industrial sensor nodes, and optical communication receivers requiring stable component supply and long-term production continuity.

Supply support for AD7478AAKSZ-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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, industrial automation, and healthcare markets.

The AD7476A/AD7477A/AD7478A family was designed to deliver high-speed, low-power SAR ADC functionality in the smallest possible packages-specifically targeting space- and energy-constrained embedded sensing applications.

FAQ

What is the maximum sampling rate supported by the AD7478AAKSZ-REEL7?

The AD7478AAKSZ-REEL7 supports a maximum throughput rate of 1.2 MSPS, achieved when using a 20 MHz SCLK and completing conversion in 12 clock cycles. This timing is specified across the full operating temperature range (–40°C to +85°C) and supply range (2.35 V to 5.25 V). At lower SCLK frequencies, throughput scales linearly-for example, 10 MHz SCLK yields 0.83 MSPS.

Does the AD7478AAKSZ-REEL7 require an external voltage reference?

No, the AD7478AAKSZ-REEL7 does not require an external voltage reference. Its analog-to-digital conversion uses an internal reference derived directly from the VDD supply, resulting in an input voltage range of 0 V to VDD. This eliminates the need for external reference components and simplifies layout, though it means full-scale accuracy tracks VDD tolerance and noise.

What is the pin configuration and package type of the AD7478AAKSZ-REEL7?

The AD7478AAKSZ-REEL7 uses a 6-lead SC70 package (2.0 mm × 1.25 mm, 0.5 mm pitch) with pins assigned as follows: Pin 1 = VDD, Pin 2 = GND, Pin 3 = VIN, Pin 4 = CS, Pin 5 = SDATA, Pin 6 = SCLK. This configuration matches the functional block diagram and pin function descriptions in the Rev. G datasheet.

How does the AD7478AAKSZ-REEL7 manage power consumption during idle periods?

The AD7478AAKSZ-REEL7 features a full power-down mode with a maximum standby current of 1 µA (typically 50 nA), activated by holding CS high while SCLK is inactive. This mode retains all internal state and allows wake-up within 1 µs. Power dissipation drops to 5 µW at 5 V, making it ideal for duty-cycled sensor systems where the ADC operates intermittently.

What serial interface protocols is the AD7478AAKSZ-REEL7 compatible with?

The AD7478AAKSZ-REEL7 is compatible with SPI, QSPI, MICROWIRE, and DSP serial interfaces. It uses a 12-cycle SCLK frame (4 leading zeros + 8-bit result + 4 trailing zeros) delivered MSB-first on the falling edge of SCLK. Its CS-controlled framing and three-state SDATA output ensure interoperability with common microcontrollers and digital signal processors without protocol translation.