Analog Devices Inc. AD7475ARM-REEL7

Overview

AD7475ARM-REEL7 from Analog Devices is a 12-bit, 1 MSPS successive-approximation ADC operating from a single 2.7 V to 5.25 V supply, featuring external 2.5 V reference input (REF IN), 68 dB SINAD at 300 kHz, and SPI-/QSPI-/MICROWIRE-/DSP-compatible serial interface. It delivers 4.5 mW max power at 3 V/1 MSPS and targets precision data acquisition in space-constrained, battery-sensitive systems.

For engineers reviewing the AD7475ARM-REEL7 datasheet, AD7475ARM-REEL7 pinout, AD7475ARM-REEL7 application, or AD7475ARM-REEL7 equivalent, key selection considerations include its external reference dependency, VDRIVE logic-level independence, no-pipeline-delay conversion control via CS, 8-lead MSOP package, and verified 1 µA full shutdown current.

Technical Context

The AD7475ARM-REEL7 implements a capacitive DAC-based successive-approximation architecture with on-chip track-and-hold, sampling on the falling edge of CS and completing conversion in exactly 16 SCLK cycles. Its analog input range is strictly 0 V to REF IN (2.5 V ±1%), requiring external decoupling ≥0.1 µF on REF IN.

It supports dual-supply logic interfacing via VDRIVE (2.7 V–5.25 V), enabling direct connection to 3 V or 5 V processors independent of VDD. Power management includes three modes: normal (1.5 mA @ 3 V/1 MSPS), partial power-down (100 µA static), and full power-down (1 µA), with 20 µs wake-up time.

Key Specifications

Pinout & Package

AD7475ARM-REEL7 is housed in an 8-lead MSOP package (3 mm × 3 mm, 0.65 mm pitch) with exposed pad for thermal enhancement. Pin 1 is REF IN; pin 2 is VIN; pin 3 is GND; pin 4 is VDD; pin 5 is SDATA; pin 6 is VDRIVE; pin 7 is SCLK; pin 8 is CS.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7475ARM-REEL7, AD7476ARMZ-REEL offers lower power but forfeits VDRIVE logic independence, while ADS7822U trades throughput and external reference control for simpler layout and integrated reference-making AD7475ARM-REEL7 optimal for high-speed, externally calibrated, mixed-voltage embedded systems.

Availability

AD7475ARM-REEL7 is available at Aetrix Electronics and suitable for battery-powered systems, medical instruments, and industrial data acquisition requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for AD7475ARM-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, headquartered in Wilmington, MA, with design centers worldwide and a 50+ year heritage in precision data conversion.

AD7475ARM-REEL7 belongs to Analog Devices' micropower SAR ADC product line, engineered specifically for space- and energy-constrained applications demanding high accuracy, low latency, and flexible voltage interfacing without sacrificing performance.

FAQ

What is the reference configuration requirement for AD7475ARM-REEL7?

The AD7475ARM-REEL7 requires an external 2.5 V ±1% reference applied to the REF IN pin (Pin 1). This reference must be decoupled with ≥0.1 µF ceramic capacitor to GND. Unlike the AD7495, it does not include an internal reference, so system-level calibration traceability depends entirely on the external reference stability and accuracy. The AD7475ARM-REEL7 will not function correctly without this externally supplied reference.

How does the VDRIVE pin affect digital interface design for AD7475ARM-REEL7?

The VDRIVE pin (Pin 6) on AD7475ARM-REEL7 sets the logic voltage thresholds independently of VDD, allowing direct connection to 3 V or 5 V microcontrollers without level shifters. When VDRIVE = 3 V, VINH ≥ 2 V and VINL ≤ 0.4 V; when VDRIVE = 5 V, VINH ≥ 4 V. This eliminates interface complexity in mixed-voltage systems and ensures robust noise margins across both supply domains.

What is the minimum quiet time required between conversions for AD7475ARM-REEL7?

The AD7475ARM-REEL7 requires a minimum tQUIET of 100 ns between consecutive conversions, as specified in Table 3 of the Rev. D datasheet. This quiet interval ensures proper settling of internal circuitry before the next CS assertion. Violating this timing may cause invalid data or increased INL/DNL errors. The value is fixed and not scalable with SCLK frequency.

Can AD7475ARM-REEL7 operate with a 2.5 V VDD supply?

No-AD7475ARM-REEL7 specifies a minimum VDD of 2.7 V per Absolute Maximum Ratings and DC Accuracy tables. Operation below 2.7 V is outside guaranteed specifications and may result in degraded INL, reduced SNR, or failure to complete conversions. The 2.5 V reference is applied to REF IN, not VDD; VDD must remain ≥2.7 V for correct internal biasing and T/H amplifier performance.

What is the purpose of the four leading zeros in the AD7475ARM-REEL7 serial data stream?

The AD7475ARM-REEL7 outputs four leading zeros followed by the 12-bit conversion result (MSB first) on SDATA. These zeros serve as framing bits that align the 12-bit word to byte boundaries in standard 8-bit microcontroller SPI peripherals, simplifying firmware parsing without bit-shifting. They are fixed and present in every conversion, regardless of input value or reference voltage.