Analog Devices Inc. AD7451BRM-REEL7

Overview

AD7451BRM-REEL7 from Analog Devices is a 12-bit, 1 MSPS pseudo-differential successive approximation register (SAR) analog-to-digital converter (ADC) operating from a single 2.7 V to 5.25 V supply. It delivers 70 dB SINAD at 100 kHz input frequency, 4 mW power dissipation at 3 V/1 MSPS, and features an external reference input (100 mV to VDD) for flexible scaling in portable data acquisition systems.

For engineers reviewing the AD7451BRM-REEL7 datasheet, AD7451BRM-REEL7 pinout, AD7451BRM-REEL7 application, or AD7451BRM-REEL7 equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternative parts with documented differences, and supply-chain support for industrial and battery-powered embedded designs.

Technical Context

The AD7451BRM-REEL7 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 timing is fully synchronized to the falling edge of CS and clocked by SCLK, enabling precise sampling control without latency uncertainty.

It operates in two distinct modes: normal mode (1.45 mA max at 3 V, 1 MSPS) and full power-down mode (1 μA max), with serial interface timing tightly coupled to SCLK frequency-conversion time is fixed at 16 SCLK cycles (888 ns at 18 MHz). The pseudo-differential input structure requires VIN– to be biased at a small DC offset (e.g., ground or 100 mV) to establish reference for VIN+.

Key Specifications

Pinout & Package

AD7451BRM-REEL7 is housed in an 8-lead SOT-23 package (JEDEC MO-178AA), with lead pitch of 0.65 mm and body dimensions 2.9 mm × 1.6 mm × 1.1 mm. Pin 1 is marked via dot; device orientation follows standard SOT-23 top-view labeling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7450BRM-REEL7 and ADS7822U, AD7451BRM-REEL7 uniquely combines 12-bit resolution, 1 MSPS speed, SOT-23 packaging, and 70 dB SINAD-making it the only option among the three suitable for high-fidelity, space-constrained, battery-operated data loggers requiring sub-microsecond timing determinism.

Availability

AD7451BRM-REEL7 is available at Aetrix Electronics and suitable for transducer interface, battery-powered instrumentation, and portable data acquisition systems requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for AD7451BRM-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 AD7451 is part of Analog Devices' precision SAR ADC product line, designed specifically for low-power, high-speed digitization in portable and space-constrained embedded systems where accuracy, size, and energy efficiency are co-critical.

FAQ

What is the maximum sampling rate supported by the AD7451BRM-REEL7?

The AD7451BRM-REEL7 supports a maximum throughput rate of 1 MSPS, achieved with an 18 MHz serial clock (SCLK) 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), with no pipeline delay affecting timing predictability.

Does the AD7451BRM-REEL7 require an external reference voltage?

Yes, the AD7451BRM-REEL7 requires an external reference voltage applied to the VREF pin. It accepts a reference from 100 mV up to VDD, with 2.5 V specified for optimal performance. The reference must be decoupled with at least a 0.1 μF capacitor to GND to ensure stable conversion accuracy and low noise.

What is the function of the VIN– pin on the AD7451BRM-REEL7?

The VIN– pin on the AD7451BRM-REEL7 serves as the pseudo-ground reference for the VIN+ input. It is not a true differential input but enables common-mode noise rejection when biased with a stable DC voltage (e.g., 0 V or 100 mV). This configuration simplifies sensor interfacing while maintaining better noise immunity than single-ended topologies.

Can the AD7451BRM-REEL7 operate from a 3.3 V supply?

Yes, the AD7451BRM-REEL7 is fully specified for operation from 2.7 V to 5.25 V, including 3.3 V nominal supplies. At 3.3 V and 1 MSPS, it consumes ≤1.45 mA (4.8 mW), delivers 70 dB SINAD at 100 kHz, and maintains full 12-bit linearity (±1.5 LSB INL max), making it ideal for modern low-voltage embedded platforms.

Is the AD7451BRM-REEL7 pin-compatible with the AD7441 series?

Yes, the AD7451BRM-REEL7 shares identical pinout, package (8-lead SOT-23), and serial interface protocol with the AD7441 series (e.g., AD7441BRM-REEL7). However, they differ in resolution (12-bit vs. 10-bit), dynamic performance (70 dB vs. 61 dB SINAD), and output data format (12-bit result vs. 10-bit result with trailing zeros), requiring firmware adaptation despite physical compatibility.