Analog Devices Inc. AD7920AKS-500RL7

Overview

AD7920AKS-500RL7 from Analog Devices is a 12-bit, 250 kSPS successive approximation ADC in a 6-lead SC70 package, operating from a single 2.35 V to 5.25 V supply. It features 71 dB SNR at 100 kHz input, 0–VDD analog input range, and SPI-/QSPI-/MICROWIRE-/DSP-compatible serial interface. It is used in portable medical instruments for high-fidelity sensor signal digitization.

For engineers reviewing the AD7920AKS-500RL7 datasheet, AD7920AKS-500RL7 pinout, AD7920AKS-500RL7 application, or AD7920AKS-500RL7 equivalent, key selection considerations include guaranteed no-missed-codes performance to 12 bits, 1 μA max standby current, 3.2 μs conversion time, flexible 2.35–5.25 V supply operation, and internal VDD-referenced architecture eliminating external reference components.

Technical Context

The AD7920AKS-500RL7 implements a charge redistribution SAR architecture with integrated track-and-hold, enabling accurate sampling of input frequencies up to 13.5 MHz (−3 dB) and 2 MHz (−0.1 dB). Its conversion is initiated on the falling edge of CS and clocked by SCLK, requiring exactly 16 cycles at 5 MHz for full 12-bit result output.

It uses VDD as its reference source, yielding a 0 V to VDD unipolar input range and eliminating need for external reference or reference buffer. The serial interface outputs four leading zeros followed by 12 MSB-first data bits, with timing parameters including tQUIET ≥ 50 ns and tPOWER-UP ≤ 1 μs from full power-down.

Key Specifications

Pinout & Package

AD7920AKS-500RL7 is housed in a 6-lead SC70 package (2.0 mm × 1.25 mm × 0.9 mm), optimized for space-constrained portable instrumentation and wearable sensors.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and MAX1116EKA+T, AD7920AKS-500RL7 delivers higher throughput (250 vs. 200/100 kSPS), superior dynamic performance (71 vs. 68/65 dB SNR), and broader supply range (2.35–5.25 V), making it optimal for space- and power-constrained precision measurement systems.

Availability

AD7920AKS-500RL7 is available at Aetrix Electronics and suitable for battery-powered systems, portable medical instruments, and optical sensor interfaces requiring stable component supply across production lifecycles.

Supply support for AD7920AKS-500RL7 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, headquartered in Wilmington, MA.

The AD7920AKS-500RL7 belongs to the AD79xx family of micropower SAR ADCs, designed specifically for portable and energy-constrained measurement applications where precision, small size, and ultra-low quiescent current are critical.

FAQ

What is the maximum sampling rate supported by the AD7920AKS-500RL7?

The AD7920AKS-500RL7 supports a maximum throughput rate of 250 kSPS, achieved using a 5 MHz serial clock and completing conversion in 16 SCLK cycles. This rate is guaranteed across the full operating temperature range (−40°C to +85°C) and supply voltage range (2.35 V to 5.25 V). Lower rates are supported down to DC via reduced SCLK frequency, maintaining full 12-bit accuracy without performance degradation.

Does the AD7920AKS-500RL7 require an external voltage reference?

No, the AD7920AKS-500RL7 does not require an external voltage reference. It uses the VDD supply rail as its internal reference source, establishing a 0 V to VDD unipolar analog input range. This architecture eliminates external reference components and associated layout complexity while maintaining guaranteed 12-bit linearity and no-missed-codes performance across its specified operating conditions.

What package type is used for the AD7920AKS-500RL7?

The AD7920AKS-500RL7 is packaged in a 6-lead SC70 (also designated SOT-323) package measuring 2.0 mm × 1.25 mm × 0.9 mm. This ultra-compact footprint is explicitly confirmed in the AD7910/AD7920 Rev. C datasheet Pin Configurations section and is distinct from the optional 8-lead MSOP variant offered for the same device family.

How does the AD7920AKS-500RL7 manage power consumption during idle periods?

The AD7920AKS-500RL7 enters a full power-down mode when CS remains high, drawing a maximum of 1 μA (typically 50 nA). This state disables the internal track-and-hold amplifier and SAR core while retaining register state. Power-up time from this mode is ≤1 μs, enabling rapid wake-and-acquire operation ideal for duty-cycled sensor systems where the AD7920AKS-500RL7 spends >99% of time in standby.

What serial interface protocols is the AD7920AKS-500RL7 compatible with?

The AD7920AKS-500RL7 features a standard 3-wire SPI-compatible serial interface (CS, SCLK, SDATA) that is explicitly documented as interoperable with QSPI™, MICROWIRE™, and DSP host controllers. It operates in Mode 0 (CPOL = 0, CPHA = 0), with data sampled on the falling edge of SCLK and CS framing each conversion cycle - no additional configuration or protocol translation is required.