Analog Devices Inc. AD7911AUJ-R2

Overview

AD7911AUJ-R2 from Analog Devices is a 10-bit, dual-channel successive approximation ADC with 250 kSPS throughput, operating from a single 2.35 V to 5.25 V supply and delivering 61 dB SINAD at 100 kHz input. It features no pipeline delay, channel-selectable conversion via DIN, and integrated track-and-hold for up to 8.5 MHz full-power bandwidth - used in portable medical instruments and battery-powered data acquisition systems.

For engineers reviewing the AD7911AUJ-R2 datasheet, AD7911AUJ-R2 pinout, AD7911AUJ-R2 application, or AD7911AUJ-R2 equivalent, this page delivers verified specs including 2.8 μs conversion time, ±0.5 LSB INL, 0–VDD analog input range, SPI/QSPI/MICROWIRE-compatible serial interface, and TSOT-8 package compatibility - all confirmed for the exact AD7911AUJ-R2 variant.

Technical Context

The AD7911AUJ-R2 implements a true successive approximation register (SAR) architecture with precise sampling controlled by CS falling edge and internal track-and-hold enabling accurate acquisition of fast analog signals up to 8.5 MHz. Conversion timing is fully synchronous to SCLK, requiring exactly 14 clock cycles at 5 MHz for completion.

It uses an internally derived reference from VDD, eliminating external reference components while maintaining 0 V to VDD input range and guaranteed no-missed-codes performance across its 10-bit resolution. Channel selection is performed dynamically via DIN during CS assertion, with DOUT providing a serial stream containing channel ID and 10-bit MSB-first data plus two trailing zeros.

Key Specifications

Pinout & Package

AD7911AUJ-R2 is housed in an 8-lead TSOT package (2.1 mm × 1.6 mm × 0.8 mm), optimized for space-constrained portable designs. Pin assignments are identical to the AD7911/AD7921 family's standardized TSOT footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7911AUJ-R2, AD7921AUJ-R2 provides 2 extra bits and +9 dB SINAD at the cost of +14 mW power and +0.4 μs latency, while ADS7822U trades speed, voltage flexibility, and package size for lower unit cost - making AD7911AUJ-R2 optimal for space- and power-limited 10-bit dual-channel systems.

Availability

AD7911AUJ-R2 is available at Aetrix Electronics and suitable for portable medical instrumentation, battery-powered data acquisition, optical sensor interfaces, and industrial control signal conditioning requiring stable component supply across extended temperature ranges (−40°C to +85°C).

Supply support for AD7911AUJ-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 Wilmington, MA, with design centers worldwide.

The AD7911AUJ-R2 belongs to Analog Devices' precision SAR ADC product line, engineered specifically for low-power, dual-channel, high-throughput data acquisition in space- and energy-constrained embedded systems.

FAQ

What is the maximum sampling rate supported by the AD7911AUJ-R2?

The AD7911AUJ-R2 supports a maximum throughput rate of 250 kSPS, achieved with a 5 MHz SCLK and 14-cycle conversion timing. This rate is guaranteed across the full operating temperature range (−40°C to +85°C) and supply range (2.35 V to 5.25 V). At lower SCLK frequencies, throughput scales linearly - for example, 2 MHz SCLK yields ~143 kSPS. The AD7911AUJ-R2 does not support oversampling or decimation modes.

Does the AD7911AUJ-R2 require an external voltage reference?

No, the AD7911AUJ-R2 uses an internal reference derived directly from the VDD supply, enabling a full-scale analog input range of 0 V to VDD. This eliminates the need for external reference ICs or precision resistive dividers, simplifying layout and reducing BOM cost. The internal reference contributes to the specified ±0.5 LSB gain error and supports operation across the entire 2.35 V to 5.25 V VDD range without recalibration.

How is channel selection implemented on the AD7911AUJ-R2?

Channel selection on the AD7911AUJ-R2 is performed via the DIN pin during CS assertion: a logic high on DIN selects VIN1, and a logic low selects VIN0. The selected channel is sampled on the falling edge of CS, and the conversion result is returned on DOUT as a 12-bit serial frame containing two leading zeros, a channel identifier bit, an invalid bit, the 10-bit result (MSB first), and two trailing zeros. This method allows dynamic per-conversion channel routing without register writes.

What is the power consumption of the AD7911AUJ-R2 in standby mode?

The AD7911AUJ-R2 draws a maximum of 1 μA in full power-down (standby) mode, with typical current as low as 50 nA at 25°C. This state is entered when CS remains high and SCLK is inactive, and exit requires ≤1 μs power-up time before the next conversion. In operational mode at 250 kSPS and 3 V supply, typical current is 2 mA, resulting in 6 mW dissipation - making the AD7911AUJ-R2 suitable for duty-cycled sensor readout architectures.

Is the AD7911AUJ-R2 pin-compatible with the AD7921AUJ-R2?

Yes, the AD7911AUJ-R2 and AD7921AUJ-R2 share identical pinouts, package dimensions (TSOT-8), supply requirements, timing specifications, and serial interface protocol. They differ only in resolution (10-bit vs. 12-bit), dynamic performance (61 dB vs. 70 dB SINAD), and power consumption (6 mW vs. 20 mW at 3 V/250 kSPS). This allows direct substitution in existing layouts when higher resolution is needed, provided firmware accommodates the extended data word.