Analog Devices Inc. AD7451ARMZ

Overview

AD7451ARMZ from Analog Devices is a 12-bit, 1 MSPS pseudo-differential successive approximation ADC in an 8-lead SOT-23 package, operating from 2.7 V to 5.25 V supply, delivering 70 dB SINAD at 100 kHz input and 4 mW power dissipation at 3 V/1 MSPS - used in portable instrumentation for high-fidelity sensor digitization.

For engineers reviewing the AD7451ARMZ datasheet, AD7451ARMZ pinout, AD7451ARMZ application, or AD7451ARMZ equivalent, this page delivers verified electrical specs, validated SOT-23 pin mapping, real-world transducer interface use cases, and two confirmed alternative parts with documented functional and application-level differences.

Technical Context

The AD7451ARMZ implements a SAR architecture with no pipeline delay, using dual capacitive DACs and a differential track-and-hold amplifier supporting up to 3.5 MHz input bandwidth. Its conversion is initiated by CS falling edge and clocked by SCLK, enabling precise sampling control.

It accepts an external reference (100 mV to VDD) on VREF, supports SPI/QSPI/MICROWIRE/DSP-compatible serial interface, and features a dedicated power-down mode drawing ≤1 μA - all while maintaining ±1 LSB DNL and 12-bit resolution across −40°C to +85°C.

Key Specifications

Pinout & Package

AD7451ARMZ is housed in an 8-lead SOT-23 package (JEDEC MO-178AA), with exposed pad not electrically connected. Thermal impedance θ_JA = 211.5°C/W enables operation up to +85°C ambient without forced airflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7451ARMZ, AD7450ARMZ trades 2 bits of resolution and 9 dB SINAD for lower cost and marginally lower power, while ADS7822U sacrifices speed and package compatibility to meet legacy industrial PCB constraints - neither offers pin-to-pin replacement.

Availability

AD7451ARMZ is available at Aetrix Electronics and suitable for portable instrumentation, battery-powered medical devices, and industrial sensor nodes requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for AD7451ARMZ 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, founded in 1965 and headquartered in Wilmington, MA.

The AD7451ARMZ belongs to Analog Devices' precision SAR ADC product line, engineered for high-speed, low-power, and high-accuracy data acquisition in space-constrained, battery-sensitive applications.

FAQ

What is the maximum sampling rate supported by the AD7451ARMZ?

The AD7451ARMZ supports a maximum throughput rate of 1 MSPS, achieved with an 18 MHz serial clock and 16 SCLK cycles per conversion. This rate is guaranteed across the full operating temperature range (−40°C to +85°C) and supply voltage range (2.7 V to 5.25 V). At lower clock speeds, throughput scales linearly - e.g., 500 kSPS at 9 MHz SCLK. The AD7451ARMZ does not support oversampling or internal decimation modes.

Does the AD7451ARMZ require an external reference voltage?

Yes, the AD7451ARMZ requires an external reference voltage applied to the VREF pin. It accepts 100 mV to VDD, with 2.5 V being the specified nominal value for full performance. The reference must be decoupled with ≥0.1 µF ceramic capacitor to GND. No internal reference is provided; omitting VREF results in undefined conversion behavior. Reference stability directly impacts gain error and SNR.

What is the meaning of "pseudo-differential" input in the AD7451ARMZ?

"Pseudo-differential" means the AD7451ARMZ accepts VIN+ and VIN– inputs where VIN– serves as a user-defined common-mode reference (not a true complementary signal), enabling rejection of noise shared between both inputs. VIN– is typically biased at a small DC offset (e.g., 0.1–0.4 V) to establish a pseudo-ground for VIN+. This differs from fully differential inputs that require matched, inverted signals and provides simpler interfacing than true differential drivers.

Can the AD7451ARMZ operate from a 3.3 V supply?

Yes, the AD7451ARMZ is fully specified for operation from 2.7 V to 5.25 V, including standard 3.3 V supplies. At 3.3 V, it delivers 70 dB SINAD at 100 kHz, consumes ≤4 mW at 1 MSPS, and maintains ±1.5 LSB INL. Logic thresholds (VINH = 2.4 V min, VINL = 0.8 V max) are compatible with 3.3 V CMOS interfaces. Decoupling remains mandatory: 0.1 µF ceramic + 10 µF tantalum to GND.

Is the AD7451ARMZ pin-compatible with the AD7441ARMZ?

Yes, the AD7451ARMZ and AD7441ARMZ share identical 8-lead SOT-23 pinouts, supply ranges, reference requirements, and serial interface timing. They differ only in resolution (12-bit vs. 10-bit), dynamic performance (70 dB vs. 61 dB SINAD), and DC accuracy (±1.5 LSB vs. ±0.5 LSB INL). Firmware and PCB layout are interchangeable; swapping requires only validation of system-level ENOB and linearity requirements.