Analog Devices Inc. AD7477ART-500RL7

Overview

AD7477ART-500RL7 from Analog Devices is a 10-bit, 1 MSPS successive-approximation ADC in a 6-lead SOT-23 package, operating from 2.7 V to 5.25 V supply. It delivers 61 dB SINAD at 100 kHz input, 70 dB SNR (typ), and 400 ns track-and-hold acquisition time. Designed for battery-powered data acquisition, it interfaces directly with microprocessors via SPI-/QSPI-/MICROWIRE-/DSP-compatible serial interface.

For engineers reviewing the AD7477ART-500RL7 datasheet, AD7477ART-500RL7 pinout, AD7477ART-500RL7 application, or AD7477ART-500RL7 equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternatives, and supply-chain support for industrial and portable embedded systems.

Technical Context

The AD7477ART-500RL7 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 16 SCLK cycles. Its internal track-and-hold amplifier supports full-power bandwidth up to 6.5 MHz and handles input frequencies exceeding 6 MHz.

Reference is derived internally from VDD, enabling a 0 V to VDD analog input range without external reference components. Serial interface timing is fully synchronous: SDATA output is valid after the SCLK falling edge, with t4 = 40 ns (max) at 5 V and t4 = 20 ns (max) at 3 V for A-version timing compliance.

Key Specifications

Pinout & Package

AD7477ART-500RL7 uses a 6-lead SOT-23 package (JEDEC MO-178AA), with 0.95 mm pitch, 2.9 mm × 1.6 mm footprint, and exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7477ARTZ-REEL7, AD7477ART-500RL7 offers identical performance with legacy leaded finish for non-RoHS production; versus ADS7822U, it trades 2-bit resolution for 5× higher throughput and integrated reference - making it the preferred choice for time-critical, space-constrained, single-supply embedded systems.

Availability

AD7477ART-500RL7 is available at Aetrix Electronics and suitable for battery-powered instrumentation, portable medical devices, and industrial motor control systems requiring stable component supply and long-term manufacturability.

Supply support for AD7477ART-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 Norwood, MA, with design centers worldwide.

The AD7476/AD7477/AD7478 family was engineered to deliver high-speed, micropower SAR conversion in ultra-small packages for portable and space-constrained embedded systems - prioritizing low standby current, supply flexibility, and simplified reference architecture.

FAQ

What is the maximum sampling frequency supported by the AD7477ART-500RL7?

The AD7477ART-500RL7 supports a maximum throughput rate of 1 MSPS, achieved with a 20 MHz SCLK and VDD between 2.7 V and 5.25 V. Conversion time is fixed at 16 SCLK cycles, so at 20 MHz the minimum conversion time is 800 ns - confirming the 1 MSPS rating. This is specified for the A version, which AD7477ART-500RL7 belongs to per Analog Devices' ordering guide.

Does the AD7477ART-500RL7 require an external voltage reference?

No, the AD7477ART-500RL7 uses an internal reference derived from VDD, establishing a 0 V to VDD analog input range. This eliminates the need for external reference components, reducing BOM cost and PCB area. The reference tracking follows VDD changes, so input full-scale scales linearly with supply voltage - a key design feature confirmed in the General Description and Specifications sections of the AD7477 datasheet.

What are the logic voltage levels compatible with the AD7477ART-500RL7 digital interface?

The AD7477ART-500RL7 supports logic inputs compliant with 3 V and 5 V systems: VINH is 2.4 V min (at VDD ≥ 2.7 V), and VINL is 0.4 V max (at VDD = 3 V) or 0.8 V max (at VDD = 5 V). Output VOH is VDD − 0.2 V min, and VOL is 0.4 V max - ensuring interoperability with standard CMOS and microcontroller I/O without level shifters, as verified in Table 2 and Pin Function Descriptions.

How does the AD7477ART-500RL7 handle power-down mode, and what is its current draw?

The AD7477ART-500RL7 enters full power-down mode when SCLK is held inactive and CS remains high, drawing ≤1 μA (max) at any VDD from 2.7 V to 5.25 V. This state disables the internal oscillator and track-and-hold amplifier, reducing power to 5 μW max at 3 V. Recovery time is 1 μs typ, enabling rapid wake-up for burst-mode acquisition - a capability explicitly documented in the Power Requirements section of the datasheet.

Can the AD7477ART-500RL7 interface directly with an STM32 microcontroller's SPI peripheral?

Yes, the AD7477ART-500RL7 is SPI-, QSPI-, MICROWIRE-, and DSP-compatible, supporting standard SPI modes with CS-active-low framing and data output on the SCLK falling edge. Its 14-bit serial frame (four leading zeros + ten data bits + two trailing zeros, MSB first) aligns with STM32's configurable SPI data length and phase settings - confirmed in the Serial Interface and Functional Block Diagram sections of the AD7477 datasheet.