Analog Devices Inc. AD7924BRU

Overview

AD7924BRU from Analog Devices is a 12-bit, 1 MSPS, 4-channel successive approximation ADC with integrated sequencer, operating from a single 2.7 V to 5.25 V supply and delivering 70 dB SNR at 50 kHz input frequency. It features four single-ended analog inputs, SPI/QSPI/MICROWIRE/DSP-compatible serial interface, and 16-lead TSSOP packaging. It is qualified for automotive applications and supports flexible input ranges (0 V to REFIN or 0 V to 2 × REFIN) with straight binary or twos complement output coding.

For engineers reviewing the AD7924BRU datasheet, AD7924BRU pinout, AD7924BRU application, or AD7924BRU equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated pin functions, confirmed automotive-grade operation, and two rigorously cross-referenced alternative parts - all grounded in Analog Devices' Rev. C datasheet and official pin configuration data.

Technical Context

The AD7924BRU implements a standard successive approximation register (SAR) architecture with no pipeline delay, where sampling is precisely controlled by the falling edge of CS and conversion is clocked entirely by SCLK. Its on-chip track-and-hold amplifier supports >8 MHz full-power bandwidth and handles input frequencies up to 1.6 MHz at 0.1 dB flatness.

It integrates a programmable channel sequencer that cycles through preselected VIN0–VIN3 inputs using ADD1/ADD0 and SEQ1/SEQ0 bits in the control register. Power management includes three modes - normal (2 mA max at 5 V), auto shutdown (960 µA typ), and full shutdown (0.5 µA max) - with VDRIVE enabling independent logic-level interfacing to 3 V or 5 V processors.

Key Specifications

Pinout & Package

AD7924BRU is housed in a 16-lead TSSOP package (4.4 mm × 5.0 mm, 0.65 mm pitch) with exposed pad for thermal enhancement. All AGND pins (Pins 4, 8, 13, 16) must be tied together and connected to a low-impedance analog ground plane to maintain DC accuracy and dynamic performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7924BRU, AD7923BRU trades sequencer autonomy for pseudo-differential input flexibility, while ADS8684IPWR prioritizes resolution and on-chip analog conditioning over speed and automotive readiness - making AD7924BRU optimal for cost-constrained, high-speed, automotive-grade 4-channel single-ended acquisition.

Availability

AD7924BRU is available at Aetrix Electronics and suitable for motor control feedback, automotive battery monitoring, industrial process sensors, and medical instrumentation requiring stable component supply, long-term lifecycle support, and AEC-Q100-compliant performance.

Supply support for AD7924BRU 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 design and manufacturing expertise spanning over 50 years.

The AD79xx family was designed specifically for high-speed, low-power, multi-channel data acquisition in space-constrained industrial, automotive, and medical systems - emphasizing sequencer autonomy, flexible power management, and robust AC/DC performance.

FAQ

What is the maximum sample rate supported by the AD7924BRU?

The AD7924BRU supports a maximum throughput rate of 1 MSPS, achieved with a 20 MHz SCLK frequency and 16 SCLK cycles per conversion. This rate is maintained across its full operating supply range (2.7 V to 5.25 V) and temperature range (−40°C to +125°C for W-grade variants). The AD7924BRU achieves this without pipeline delay, ensuring deterministic timing for time-critical applications like motor control and power quality monitoring.

Does the AD7924BRU require an external reference voltage?

Yes, the AD7924BRU requires an external reference voltage applied to the REFIN pin. The datasheet specifies 2.5 V ±1% for guaranteed performance, with REFIN input impedance of 36 kΩ at 1 MSPS. The device supports two input ranges - 0 V to REFIN or 0 V to 2 × REFIN - selectable via the RANGE bit in the control register, but the latter requires AVDD between 4.75 V and 5.25 V.

How does the channel sequencer function in the AD7924BRU?

The AD7924BRU's sequencer uses SEQ1/SEQ0 and ADD1/ADD0 bits in the 16-bit control register to define a fixed sequence of up to four channels (VIN0–VIN3). Once enabled, it automatically cycles through the programmed order without host processor intervention. For example, setting SEQ=01 and ADD=00–11 converts VIN0 → VIN1 → VIN2 → VIN3 repeatedly - reducing firmware load in multi-sensor data acquisition systems.

Is the AD7924BRU pin-compatible with other members of the AD7904/AD7914/AD7924 family?

Yes, the AD7924BRU shares identical pinout, package (16-lead TSSOP), and serial interface protocol with AD7904BRU and AD7914BRU. All three devices use the same control register structure and timing specifications. However, resolution (8/10/12-bit), dynamic performance (SINAD/SNR), and DC accuracy (INL/DNL) differ - requiring firmware validation when substituting across the family.

What power-saving modes does the AD7924BRU support?

The AD7924BRU offers three power management modes: Normal mode (2 mA max at 5 V), Auto Shutdown (960 µA typ at 250 kSPS), and Full Shutdown (0.5 µA max). Full Shutdown disables the internal reference buffer and analog circuitry, while Auto Shutdown powers down between conversions. Both modes retain register settings and resume operation within 1 µs, making them ideal for burst-mode sensing in portable and automotive applications.