Analog Devices Inc. AD7477AAKS-REEL7

Overview

AD7477AAKS-REEL7 from Analog Devices is a 10-bit, 1 MSPS successive-approximation analog-to-digital converter (ADC) in a 6-lead SC70 package, operating from 2.35 V to 5.25 V supply. It delivers 61 dB SINAD at 100 kHz input, 7 ns minimum SCLK high pulse width, and 250 ns track-and-hold acquisition time-enabling high-fidelity signal digitization in space-constrained battery-powered instrumentation.

For engineers reviewing the AD7477AAKS-REEL7 datasheet, AD7477AAKS-REEL7 pinout, AD7477AAKS-REEL7 application, or AD7477AAKS-REEL7 equivalent, key selection considerations include its 10-bit resolution with ±0.5 LSB INL, SPI/QSPI/MICROWIRE-compatible serial interface, 1 µA standby current, and SC70 footprint compatibility with layout-sensitive portable medical and telecom front-ends.

Technical Context

The AD7477AAKS-REEL7 implements a single-supply successive-approximation architecture with internal track-and-hold, sampling on the falling edge of CS and initiating conversion simultaneously. Its reference is derived directly from VDD, enabling a 0 V to VDD analog input range without external reference components.

Conversion timing is fully synchronous to SCLK: 14 clock cycles required per sample, with no pipeline delay and guaranteed 1 MSPS throughput at 20 MHz SCLK. Digital I/Os support 2.35 V–5.25 V logic levels, including 0.4 V VOL at 200 µA sink and VDD − 0.2 V VOH at 200 µA source.

Key Specifications

Pinout & Package

AD7477AAKS-REEL7 uses a 6-lead SC70 package with exposed pad (not electrically connected), rated for −40°C to +85°C operation. Pin 1 is marked by a dot; device orientation follows JEDEC MO-220 standard.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit SAR ADC applications.

Compared with AD7477AAKS-REEL7, AD7477ARMZ-REEL offers identical performance in a larger, thermally superior package, while MAX1116EKA+T trades supply flexibility and reference simplicity for lower unit cost in narrow-voltage designs.

Availability

AD7477AAKS-REEL7 is available at Aetrix Electronics and suitable for battery-powered systems, portable medical instruments, and optical sensor interfaces requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AD7477AAKS-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 AD7476A/AD7477A/AD7478A family was designed specifically for space- and power-constrained applications demanding high-speed, low-voltage ADC functionality in miniature packages-targeting portable instrumentation, telecom front-ends, and energy-harvesting sensor nodes.

FAQ

What is the maximum sampling rate supported by the AD7477AAKS-REEL7?

The AD7477AAKS-REEL7 supports a maximum throughput rate of 1 MSPS, achieved with a 20 MHz serial clock frequency and 14 SCLK cycles per conversion. At lower SCLK frequencies, the effective sampling rate scales linearly-for example, 5 MHz SCLK yields ~315 kSPS. The part guarantees no pipeline delay, ensuring deterministic timing for real-time control loops.

Does the AD7477AAKS-REEL7 require an external voltage reference?

No, the AD7477AAKS-REEL7 uses an internal VDD-referenced architecture, meaning its full-scale analog input range is 0 V to VDD without external components. This eliminates the need for precision reference ICs or resistive dividers, simplifying design and reducing bill-of-materials cost in battery-operated systems where supply voltage may vary.

What are the absolute maximum ratings for analog input voltage on the AD7477AAKS-REEL7?

The AD7477AAKS-REEL7 specifies an absolute maximum analog input voltage of −0.3 V to VDD + 0.3 V. Exceeding this range risks permanent damage. Under normal operation, the input must remain within 0 V to VDD for proper conversion; inputs beyond this range will saturate or produce invalid codes, even if within absolute limits.

How does the AD7477AAKS-REEL7 handle power-down mode, and what is the wake-up time?

The AD7477AAKS-REEL7 enters full power-down mode when CS remains high and SCLK is inactive, drawing ≤1 µA. Power-up time from this state is guaranteed ≤1 µs, allowing rapid resumption of sampling after wake events. During wake-up, the internal track-and-hold amplifier stabilizes before the first conversion, ensuring valid data from cycle one.

Is the AD7477AAKS-REEL7 compatible with standard SPI interfaces?

Yes, the AD7477AAKS-REEL7 is fully SPI/QSPI/MICROWIRE/DSP-compatible: it uses CS as frame select, SCLK as master clock, and SDATA as MOSI-only output (no input). Data is clocked out MSB-first on the falling edge of SCLK, with four leading zeros followed by 10 data bits and two trailing zeros-requiring no protocol translation in standard SPI controller implementations.