Analog Devices Inc. AD7899BRZ-1

Overview

AD7899BRZ-1 from Analog Devices is a 14-bit, 400 kSPS successive-approximation ADC with integrated track/hold, 2.5 V reference, and high-speed parallel interface. It operates from a single 5 V supply, supports ±10 V and ±5 V bipolar input ranges, and delivers 78 dB SNR at 100 kHz input - used in precision data acquisition systems for industrial process control and automated test equipment.

For engineers reviewing the AD7899BRZ-1 datasheet, AD7899BRZ-1 pinout, AD7899BRZ-1 application, or AD7899BRZ-1 equivalent, key selection criteria include its 2.2 µs conversion time, ±1.5 LSB INL (B-grade), 0.3 µs track/hold acquisition, 3 V/5 V digital I/O compatibility via VDRIVE, and SOIC-28 package with overvoltage protection up to ±18 V on analog inputs.

Technical Context

The AD7899BRZ-1 implements a laser-trimmed internal clock oscillator enabling fixed 400 kSPS throughput without external timing components; it also accepts an external 6.5 MHz clock via CLKIN for flexible rate control. Its track/hold amplifier achieves 500 kHz –0.1 dB full-power bandwidth and 4.5 MHz –3 dB bandwidth, supporting accurate digitization of fast-changing analog signals.

Conversion is initiated by a rising edge on CONVST, which places the track/hold into hold mode and triggers the 16-cycle SAR sequence. BUSY/EOC serves dual-mode signaling: asserted high during conversion (BUSY) or pulsed low at completion (EOC), configurable by CONVST state at end-of-conversion.

Key Specifications

Pinout & Package

AD7899BRZ-1 is housed in a 28-lead SOIC package (R-28), RoHS-compliant, with standard 0.3-inch body width and 0.050-inch lead pitch. Thermal resistance θ_JA = 95°C/W supports operation up to +85°C ambient.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed 14-bit ADC applications.

Compared with AD7899ARZ-1, the AD7899BRZ-1 provides tighter linearity for metrology-grade measurements; compared with ADS8515IPW, it delivers higher throughput and simpler hardware integration via parallel interface and integrated reference, at the expense of 2-bit resolution.

Availability

AD7899BRZ-1 is available at Aetrix Electronics and suitable for industrial process monitoring, automated test equipment, and portable data loggers requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for AD7899BRZ-1 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, serving industrial, automotive, communications, and healthcare markets since 1965.

The AD7899 product line delivers high-speed, low-power, precision ADCs with integrated signal conditioning for demanding data acquisition applications where accuracy, speed, and reliability are critical.

FAQ

What input voltage ranges does the AD7899BRZ-1 support?

The AD7899BRZ-1 supports ±10 V and ±5 V bipolar analog input ranges. Configuration is achieved by connecting VINB to AGND for ±10 V operation or tying VINA and VINB together for ±5 V operation. Input overvoltage protection allows up to ±18 V without damage when using the ±10 V range, making it robust for industrial field connections.

How does the AD7899BRZ-1 handle reference voltage selection?

The AD7899BRZ-1 features a dedicated VREF pin that provides access to its internal 2.5 V ±20 mV reference or accepts an external 2.5 V ±5% reference. A 0.1 µF capacitor must be placed between VREF and AGND when using the internal reference. External references like the AD780 or REF43 can overdrive the internal source, enabling system-level reference synchronization and improved temperature stability.

What is the function of the VDRIVE pin on the AD7899BRZ-1?

The VDRIVE pin supplies power to the AD7899BRZ-1's digital I/O circuitry and determines logic threshold levels. It may be tied to 5 V for standard TTL/CMOS compatibility or to 3 V ±10% to interface directly with 3 V microcontrollers and DSPs without external level shifters. This flexibility reduces BOM count and simplifies mixed-voltage system design.

Can the AD7899BRZ-1 operate with an external clock source?

Yes, the AD7899BRZ-1 supports external clocking via the CLKIN pin. When CLKIN is high on the rising edge of CONVST, the device uses the external clock (up to 6.5 MHz) for conversion timing; otherwise, it defaults to its internal laser-trimmed oscillator. The external clock option allows precise synchronization with system timing domains, though the internal clock delivers optimal 400 kSPS throughput with minimal jitter.

What is the significance of the STBY pin on the AD7899BRZ-1?

The STBY pin places the AD7899BRZ-1 into low-power standby mode when driven low, reducing supply current to 20 µA typical. In this state, the internal reference and oscillator remain active but the ADC core and track/hold are disabled. This feature enables rapid wake-up (<5 µs) for duty-cycled data acquisition, significantly extending battery life in portable instrumentation without sacrificing responsiveness.