Analog Devices Inc. AD7912AUJ-R2

Overview

AD7912AUJ-R2 from Analog Devices is a 10-bit, 2-channel, successive approximation ADC with 1 MSPS throughput, operating from 2.35 V to 5.25 V supply and delivering 61 dB SINAD at 100 kHz input. It features daisy-chain capability, no pipeline delay, and integrated track-and-hold for high-fidelity sampling in portable medical instruments and battery-powered data acquisition systems.

For engineers reviewing the AD7912AUJ-R2 datasheet, AD7912AUJ-R2 pinout, AD7912AUJ-R2 application, or AD7912AUJ-R2 equivalent, this page provides verified specifications, TSOT-8 package mapping, SPI/QSPI/MICROWIRE-compatible serial interface details, channel-isolation–driven dual-input use cases, and validated alternative parts for low-power, dual-channel SAR ADC selection.

Technical Context

The AD7912AUJ-R2 implements a true successive approximation register (SAR) architecture with precise CS-controlled sampling initiation and single-cycle conversion-no latency or pipelining. Its internal VDD-referenced ADC core eliminates external reference components while supporting 0 V to VDD analog input range across both VIN0 and VIN1 channels.

Conversion timing is fully synchronous to SCLK (up to 18 MHz), requiring exactly 14 clock cycles per sample; channel selection is dynamically controlled via DIN bitstream, and output includes channel ID + mode bits before data bits. Daisy-chain mode enables multi-ADC cascading without additional control lines.

Key Specifications

Pinout & Package

AD7912AUJ-R2 is housed in an 8-lead TSOT package (2.1 mm × 1.6 mm × 0.8 mm), optimized for space-constrained PCB layouts in portable electronics. Pin numbering follows standard TSOT top-view orientation with Pin 1 at bottom-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel SAR ADC applications.

Compared with AD7912AUJ-R2, AD7922AUJ-R2 trades higher resolution and SNR for increased latency and power, while ADS7822U sacrifices dual-channel concurrency and daisy-chain flexibility for lower unit cost and simpler interface-making AD7912AUJ-R2 optimal for balanced throughput, power, and multi-signal integration.

Availability

AD7912AUJ-R2 is available at Aetrix Electronics and suitable for battery-powered medical instruments, portable data loggers, industrial motor controllers, and optical smoke detectors requiring stable component supply across extended production lifecycles.

Supply support for AD7912AUJ-R2 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 AD7912AUJ-R2 belongs to Analog Devices' precision SAR ADC product line, engineered specifically for space- and power-constrained applications demanding dual-channel acquisition, low-latency conversion, and robust serial interfacing without external references.

FAQ

What is the maximum sampling rate supported by the AD7912AUJ-R2?

The AD7912AUJ-R2 supports a maximum throughput rate of 1 MSPS, achieved with an SCLK frequency of up to 18 MHz and exactly 14 clock cycles per conversion. At lower SCLK speeds (e.g., 5 MHz), the device maintains functional operation but reduces effective sample rate to ~315 kSPS while preserving full 10-bit accuracy and timing integrity. This scalability makes AD7912AUJ-R2 adaptable to both high-speed monitoring and ultra-low-power burst-mode applications.

Does the AD7912AUJ-R2 require an external voltage reference?

No, the AD7912AUJ-R2 uses its VDD supply rail as the internal reference source, enabling a full-scale input range of 0 V to VDD without external components. This simplifies BOM, reduces PCB area, and improves supply rejection-provided VDD remains stable within 2.35 V to 5.25 V. For applications requiring higher absolute accuracy, external reference buffering may be added, but it is not mandatory for basic operation of AD7912AUJ-R2.

How does the daisy-chain mode work on the AD7912AUJ-R2?

In daisy-chain mode, multiple AD7912AUJ-R2 devices are connected serially: DOUT of one feeds DIN of the next, sharing common SCLK and CS lines. A single CS assertion triggers simultaneous sampling across all devices, and subsequent SCLK pulses shift out results sequentially-starting with the last device's data. This eliminates address decoding logic and preserves SPI compatibility while scaling channel count linearly. The AD7912AUJ-R2's channel ID bit ensures unambiguous assignment of each 10-bit word to its source channel.

What is the significance of the 90 dB channel-to-channel isolation specification for AD7912AUJ-R2?

The 90 dB typical channel-to-channel isolation means that a full-scale signal applied to VIN1 produces less than −90 dB (i.e., ~0.003% of full scale) crosstalk at VIN0 during conversion-critical when measuring two physically coupled but functionally independent signals (e.g., motor phase voltage and case temperature). This level of isolation allows AD7912AUJ-R2 to replace discrete single-channel ADCs in many dual-sensor systems without hardware guard-banding or sequential sampling delays.

Can the AD7912AUJ-R2 operate from a 2.5 V supply?

Yes, the AD7912AUJ-R2 is fully specified for operation from 2.35 V to 5.25 V, including 2.5 V. At 2.5 V, it delivers 6 mW max power dissipation at 1 MSPS, 61 dB SINAD at 100 kHz, and maintains all timing parameters-including 290 ns track-and-hold acquisition and 777 ns conversion time. Logic thresholds automatically adapt: VINH = 0.7 × VDD (1.75 V min) and VINL = 0.3 V max, ensuring reliable interface with 2.5 V microcontrollers without level-shifting circuitry.