Analog Devices Inc. AD7478AAKS-REEL7

Overview

AD7478AAKS-REEL7 from Analog Devices is an 8-bit, 1.2 MSPS successive-approximation analog-to-digital converter (ADC) in a 6-lead SC70 package, operating from a single 2.35 V to 5.25 V supply. It delivers 49 dB SINAD at 100 kHz input, 7 ns minimum SCLK-to-data hold time (VDD > 3.6 V), and 1 μA max standby current - enabling high-speed, low-power data acquisition in space-constrained portable systems.

For engineers reviewing the AD7478AAKS-REEL7 datasheet, AD7478AAKS-REEL7 pinout, AD7478AAKS-REEL7 application, or AD7478AAKS-REEL7 equivalent, key selection considerations include its 12-cycle serial interface timing, internal VDD-referenced full-scale range (0 V to VDD), guaranteed no-missed-codes performance, and compatibility with SPI/QSPI/MICROWIRE/DSP controllers in battery-powered instrumentation and optical sensor front-ends.

Technical Context

The AD7478AAKS-REEL7 implements a standard successive-approximation register (SAR) architecture with no pipeline delay, where conversion is initiated on the falling edge of CS and completed in exactly 12 SCLK cycles. Sampling is controlled by a track-and-hold amplifier with 225 ns acquisition time and 13.5 MHz full-power bandwidth at 3 dB.

Its serial interface operates synchronously with SCLK, outputs MSB-first data with four leading zeros followed by eight data bits and four trailing zeros, and supports flexible clock speeds from 10 kHz to 20 MHz - enabling dynamic power scaling via adjustable throughput and integrated 1 μA standby mode.

Key Specifications

Pinout & Package

AD7478AAKS-REEL7 is housed in a 6-lead SC70 package (2.0 mm × 1.25 mm, 0.9 mm height), optimized for high-density PCB layouts in portable electronics. Pin assignments are validated per Analog Devices Rev. G datasheet Figure 5.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822UID and MAX11100ETE+, AD7478AAKS-REEL7 uniquely balances 1.2 MSPS speed, 2.35–5.25 V flexibility, SC70 compactness, and VDD-referenced simplicity - making it optimal for space-constrained, multi-rail portable systems where moderate resolution suffices.

Availability

AD7478AAKS-REEL7 is available at Aetrix Electronics and suitable for battery-powered data loggers, optical sensor interfaces, portable medical instruments, industrial control loop monitors, and handheld communication devices requiring stable component supply across production lifecycles.

Supply support for AD7478AAKS-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, with R&D and manufacturing infrastructure spanning North America, Europe, and Asia.

The AD7476A/AD7477A/AD7478A family was designed to deliver high-speed, low-power SAR ADC functionality in ultra-small packages for portable and energy-sensitive applications - prioritizing minimal board area, wide supply flexibility, and seamless microcontroller interfacing.

FAQ

What is the maximum sampling rate supported by the AD7478AAKS-REEL7?

The AD7478AAKS-REEL7 supports a maximum throughput rate of 1.2 MSPS, achieved when using a 20 MHz SCLK and operating in normal mode. This corresponds to a minimum conversion time of 600 ns (12 SCLK cycles), and the device maintains guaranteed specifications across its full 2.35 V to 5.25 V supply range at this rate.

Does the AD7478AAKS-REEL7 require an external voltage reference?

No, the AD7478AAKS-REEL7 does not require an external voltage reference. It uses an internal reference derived from VDD, resulting in an analog input range of 0 V to VDD. This simplifies system design by eliminating external reference components and associated layout constraints while maintaining monotonicity and no-missed-codes performance.

What package type and dimensions does the AD7478AAKS-REEL7 use?

The AD7478AAKS-REEL7 is packaged in a 6-lead SC70 (SOT-323) case measuring 2.0 mm × 1.25 mm with a maximum height of 0.9 mm. This ultra-compact footprint is specified in Analog Devices' Rev. G datasheet and supports high-density routing in space-limited applications such as wearables and handheld diagnostics.

How does the serial interface of the AD7478AAKS-REEL7 format its output data?

The AD7478AAKS-REEL7 outputs a 12-bit serial frame on SDATA: four leading zeros, followed by eight data bits (MSB first), followed by four trailing zeros. This fixed-length format ensures consistent timing and simplifies firmware parsing across varying supply voltages and clock speeds, with data valid on the falling edge of SCLK.

What is the guaranteed DC accuracy of the AD7478AAKS-REEL7 over temperature?

The AD7478AAKS-REEL7 guarantees integral nonlinearity (INL) of ±0.3 LSB max, differential nonlinearity (DNL) of ±0.3 LSB max, offset error of ±0.3 LSB max, and gain error of ±0.3 LSB max over its operating temperature range of –40°C to +85°C (A grade). These specifications ensure monotonic behavior and predictable transfer function stability in embedded control applications.