Analog Devices Inc. AD7904BRUZ

Overview

AD7904BRUZ from Analog Devices is an 8-bit, 4-channel, 1 MSPS successive approximation ADC with integrated channel sequencer, operating from a single 2.7 V to 5.25 V supply and consuming ≤6 mW at 3 V/1 MSPS. It features four single-ended analog inputs (VIN0–VIN3), SPI-compatible serial interface, and supports 0 V to REFIN or 0 V to 2 × REFIN input ranges - used in industrial sensor data acquisition systems requiring compact, low-power multichannel sampling.

For engineers reviewing the AD7904BRUZ datasheet, AD7904BRUZ pinout, AD7904BRUZ application, or AD7904BRUZ equivalent, this page delivers verified specifications, validated pin functions, confirmed automotive-qualified package (16-lead TSSOP), and real-world sequencing behavior - all aligned to Rev. C datasheet for design-in accuracy and BOM continuity.

Technical Context

The AD7904BRUZ implements a standard SAR architecture with no pipeline delay, where conversion is initiated on the falling edge of CS and controlled entirely by SCLK frequency (up to 20 MHz). Its internal track-and-hold amplifier supports >8 MHz input bandwidth and maintains ±0.2 LSB INL and ±0.2 LSB DNL across −40°C to +85°C.

Sequencing is managed via a 2-bit address register (ADD1/ADD0) and SEQ1/SEQ0 bits, enabling preprogrammed cycling among VIN0–VIN3. The VDRIVE pin decouples logic-level compatibility (3 V or 5 V) from AVDD, allowing direct interfacing with mixed-voltage microcontrollers without level shifters.

Key Specifications

Pinout & Package

AD7904BRUZ is housed in a 16-lead TSSOP (3.0 mm × 4.4 mm, 0.65 mm pitch), qualified for automotive applications per AEC-Q100. All AGND pins (4, 8, 13, 16) must be tied together at a single low-impedance analog ground point; AVDD pins (5, 6) require local 100 nF ceramic decoupling.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 4-channel SAR ADC applications.

Compared with AD7904BRUZ, AD7914BRUZ provides 2 extra bits of resolution at modest SNR improvement but higher offset error, while ADS7953IRHBT offers scalability to 16 channels at the cost of increased software complexity and loss of VDRIVE flexibility - making AD7904BRUZ optimal for cost- and space-constrained 4-channel systems needing guaranteed monotonicity and mixed-voltage ease-of-use.

Availability

AD7904BRUZ is available at Aetrix Electronics and suitable for industrial sensor hubs, motor control feedback systems, automotive cabin monitoring, and portable diagnostic tools requiring stable component supply, AEC-Q100 compliance, and long-term production continuity.

Supply support for AD7904BRUZ 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, with R&D and manufacturing facilities worldwide.

The AD7904BRUZ belongs to the AD7904/AD7914/AD7924 family of low-power, high-speed SAR ADCs designed specifically for multichannel data acquisition in space- and power-constrained industrial and automotive systems.

FAQ

What is the maximum sampling rate supported by the AD7904BRUZ?

The AD7904BRUZ supports a maximum throughput rate of 1 MSPS, achieved with a 20 MHz SCLK. Conversion time is fixed at 16 SCLK cycles (800 ns max), and the device guarantees no pipeline delay - meaning each sample is acquired and digitized in a single, deterministic cycle without latency accumulation across consecutive conversions. This makes AD7904BRUZ suitable for real-time control applications where timing predictability is essential.

Does the AD7904BRUZ require an external reference voltage?

Yes, the AD7904BRUZ requires an external reference voltage applied to the REFIN pin. The datasheet specifies 2.5 V ±1% for guaranteed performance, and the internal reference input impedance is 36 kΩ at 1 MSPS. While the part does not include an internal reference, its flexible input range (0 V to REFIN or 0 V to 2 × REFIN) allows use with precision external references like the ADR4525 or buffered bandgap sources - ensuring stable full-scale definition across temperature and supply variations.

How does the channel sequencer work on the AD7904BRUZ?

The AD7904BRUZ sequencer is configured via the control register's SEQ1/SEQ0 and ADD1/ADD0 bits. It supports programmable cycling through VIN0–VIN3 in user-defined order (e.g., 0→1→2→3 or 0→2→1→3), with automatic channel selection on each CS-initiated conversion. The DOUT stream includes two address bits identifying the sampled channel, eliminating host software overhead for channel tracking - a key advantage over non-sequencing ADCs requiring explicit address writes before every conversion.

Can the AD7904BRUZ operate with different supply voltages for analog and digital interfaces?

Yes - the AD7904BRUZ uses separate AVDD (analog supply, 2.7–5.25 V) and VDRIVE (digital I/O supply, 2.7–5.25 V) pins. This allows independent voltage setting: for example, AVDD = 5 V for optimal analog performance while VDRIVE = 3 V to interface directly with a 3 V microcontroller's GPIO, without external level shifters. This dual-supply flexibility simplifies mixed-voltage system design and reduces bill-of-materials cost.

Is the AD7904BRUZ pin-compatible with other members of the AD7904/AD7914/AD7924 family?

Yes, the AD7904BRUZ is pin-compatible with AD7914BRUZ and AD7924BRUZ in the same 16-lead TSSOP package. All share identical pinout, timing, serial protocol, and register map - differing only in resolution (8-/10-/12-bit), dynamic performance (SINAD/SNR), and DC accuracy specs (INL/DNL). This enables drop-in upgrades during design iteration or production ramp without PCB revision, provided firmware handles the varying data word length (8 vs. 10 vs. 12 bits).