Analog Devices Inc. AD7484BST

Overview

AD7484BST from Analog Devices is a 14-bit, 3 MSPS successive approximation register (SAR) analog-to-digital converter with parallel interface, 40 MHz input bandwidth, internal 2.5 V reference, and full-scale overrange capability via 15th bit. It operates from a single 5 V supply and supports nap mode (2.5 mW) and standby mode (2 μA), targeting high-speed data acquisition in instrumentation and communication systems.

For engineers reviewing the AD7484BST datasheet, AD7484BST pinout, AD7484BST application, or AD7484BST equivalent, key selection criteria include throughput rate (3 MSPS), dc accuracy (±1 LSB INL), power modes (nap/standby), input range flexibility (−200 mV to +2.7 V), and parallel interface timing compatibility with microcontrollers and DSPs.

Technical Context

The AD7484BST implements an algorithmic SAR architecture with capacitive DAC and integrated track-and-hold, delivering zero pipeline delay and 300 ns conversion time. Its analog front-end supports 40 MHz full-power bandwidth and ±200 mV input offset shift, enabling direct interfacing with single-supply op amps like AD8021.

It features dual parallel interface modes (Mode 1 and Mode 2), configurable via MODE1/MODE2 pins, with BUSY-driven or CONVST-synchronized data latching. The VDRIVE pin (2.7 V to 5.25 V) decouples digital I/O voltage from AVDD/DVDD, allowing mixed-voltage system integration.

Key Specifications

Pinout & Package

The AD7484BST is housed in a 48-lead LQFP package (7 mm × 7 mm, 0.5 mm pitch) with exposed pad for thermal management, rated for −40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed SAR ADC applications.

Compared with AD7484BST, AD7482BST offers identical footprint and interface at reduced resolution, while ADS8326IPFBT trades speed and parallel simplicity for higher resolution and lower power - making AD7484BST optimal for 14-bit, 3 MSPS, parallel-interfaced systems requiring minimal latency.

Availability

AD7484BST is available at Aetrix Electronics and suitable for high-speed data acquisition, automated test equipment, communications IF sampling, and industrial process monitoring requiring stable component supply across extended temperature ranges.

Supply support for AD7484BST 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.

The AD7484BST belongs to Analog Devices' high-speed SAR ADC product line, designed specifically for applications demanding low-latency, high-resolution digitization with flexible power management and robust dc/ac performance.

FAQ

What is the maximum input frequency the AD7484BST can accurately digitize?

The AD7484BST has a full-power bandwidth of 40 MHz at the −3 dB point, meaning it can accurately capture analog signals with fundamental frequencies up to 40 MHz while maintaining specified SINAD and THD performance. For Nyquist-compliant sampling, the maximum input tone should be ≤1.5 MHz when operating at its full 3 MSPS throughput rate.

Does the AD7484BST require an external reference, or does it have an internal one?

The AD7484BST includes an internal 2.5 V reference with ±100 mV error over −40°C to +85°C, making it fully functional without external components. However, it also supports an external 2.5 V ±1% reference applied to the REFIN pin for improved accuracy in metrology-grade applications.

How does the D14 pin function in the AD7484BST?

The D14 pin on the AD7484BST serves as an overrange indicator: it outputs logic high when the analog input exceeds ±8% of the nominal full-scale range (i.e., outside −200 mV to +2.7 V). This 15th-bit flag enables real-time detection of signal clipping without requiring post-processing analysis of the 14-bit data word.

Can the AD7484BST operate with a 3.3 V digital interface while using a 5 V analog supply?

Yes - the AD7484BST's VDRIVE pin allows independent setting of digital I/O voltage levels from 2.7 V to 5.25 V. By applying 3.3 V to VDRIVE, all digital pins (CS, RD, BUSY, D0–D14) operate at 3.3 V logic levels while AVDD/DVDD remain at 5 V, enabling seamless interfacing with 3.3 V microcontrollers without level shifters.

What is the purpose of the CLIP pin on the AD7484BST?

The CLIP pin on the AD7484BST enables hardware-based output clipping: when driven high, the ADC forces the output code to all 1s for inputs above positive full scale or all 0s for inputs below negative full scale. This prevents ambiguous codes during overvoltage events and simplifies downstream signal validation in safety-critical monitoring systems.