Analog Devices Inc. AD7451ART-REEL7

Overview

AD7451ART-REEL7 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 and delivering 70 dB SINAD at 100 kHz input frequency. It features no pipeline delay, SPI-/QSPI-/MICROWIRE-compatible serial interface, and 1 μA power-down current - used in portable instrumentation for high-fidelity sensor digitization.

For engineers reviewing the AD7451ART-REEL7 datasheet, AD7451ART-REEL7 pinout, AD7451ART-REEL7 application, or AD7451ART-REEL7 equivalent, key selection criteria include guaranteed 12-bit resolution with ±1 LSB INL (B version), pseudo-differential input structure requiring VIN– bias, external reference support from 100 mV to VDD, and SOT-23 thermal impedance of 91.99°C/W.

Technical Context

The AD7451ART-REEL7 implements a capacitive SAR architecture with dual DAC arrays and a differential track-and-hold amplifier capable of 3.5 MHz input bandwidth. Conversion is initiated by CS falling edge and clocked by SCLK, with 16-cycle conversion time at 18 MHz SCLK yielding 1 MSPS throughput.

Its pseudo-differential input requires VIN– biased to a stable DC level (e.g., ground or offset) to establish reference for VIN+, while VREF is externally supplied (2.5 V typical, 100 mV to VDD range). The straight binary output format and three-state SDATA support direct interfacing to microcontrollers without glue logic.

Key Specifications

Pinout & Package

AD7451ART-REEL7 is housed in an 8-lead SOT-23 package (JEDEC MO-178AA), with 0.65 mm lead pitch and thermal impedance θJC = 91.99°C/W. Pin 1 is VREF (top-left when notch/identifier faces up); pin 8 is VDD (bottom-left).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7451ART-REEL7, AD7452BRMZ-REEL trades SOT-23 compactness for integrated reference and wider I/O flexibility, while ADS7822U offers SOIC compatibility at reduced speed and power efficiency - making AD7451ART-REEL7 optimal for size- and speed-critical portable instrumentation.

Availability

AD7451ART-REEL7 is available at Aetrix Electronics and suitable for portable instrumentation, battery-powered data loggers, and transducer interface applications requiring stable component supply, long-term manufacturability, and consistent parametric performance across production lots.

Supply support for AD7451ART-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 Norwood, MA, with design centers worldwide and ISO 9001-certified manufacturing.

The AD7451ART-REEL7 belongs to Analog Devices' precision SAR ADC product line, engineered for low-power, high-speed digitization in space-constrained portable and battery-operated systems - emphasizing accuracy, small footprint, and seamless microcontroller integration.

FAQ

What is the maximum recommended reference voltage for AD7451ART-REEL7?

The AD7451ART-REEL7 supports VREF from 100 mV up to VDD (2.7 V to 5.25 V). While 2.5 V is the specified reference for guaranteed performance, operation with VREF = VDD is permitted and maintains full 12-bit linearity per datasheet Table 1. Exceeding VDD on VREF violates absolute maximum ratings and risks damage.

Does AD7451ART-REEL7 require external decoupling capacitors, and if so, what values?

Yes - AD7451ART-REEL7 requires two decoupling capacitors on VDD: a 0.1 μF ceramic capacitor placed as close as possible to the VDD pin, and a 10 μF tantalum capacitor elsewhere on the supply rail. VREF also requires ≥0.1 μF ceramic decoupling to ground, as stated in Pin Function Descriptions (Table 5) and Figure 14 of the datasheet.

How does the pseudo-differential input of AD7451ART-REEL7 differ from true differential input?

AD7451ART-REEL7's pseudo-differential input uses VIN– as a fixed DC bias point (e.g., ground or offset voltage) rather than accepting a complementary signal. VIN+ is measured relative to that bias, rejecting common-mode noise on VIN+ but not providing full differential noise cancellation. True differential inputs (e.g., AD7685) accept inverted VIN− and compute difference internally.

Can AD7451ART-REEL7 interface directly with a 1.8 V microcontroller SPI bus?

No - AD7451ART-REEL7 logic thresholds require VINH ≥ 2.4 V and VINL ≤ 0.8 V (Table 1), making it incompatible with 1.8 V IO without level translation. Its VDD range (2.7–5.25 V) also precludes direct 1.8 V supply. Use a bidirectional level shifter or select a 1.8 V–tolerant ADC like AD7476A for such interfaces.

What is the guaranteed integral nonlinearity (INL) specification for AD7451ART-REEL7 across temperature?

For the B-version (which AD7451ART-REEL7 is, per Ordering Guide and Rev. D datasheet), INL is guaranteed ±1 LSB maximum over −40°C to +85°C. This is explicitly stated in Table 1 under "A Version" and "B Version" columns for Integral Nonlinearity (INL), with B Version listing ±1 LSB max.