Analog Devices Inc. AD7899BR-3REEL7

Overview

AD7899BR-3REEL7 from Analog Devices is a 14-bit, 400 kSPS successive-approximation ADC with ±2.5 V analog input range, internal 2.5 V reference, and single 5 V supply operation. It features 2.2 µs conversion time, 0.3 µs track/hold acquisition, and overvoltage protection up to ±18 V on analog inputs. Used in precision data acquisition systems requiring high DC accuracy and fast sampling, such as industrial process monitoring and automated test equipment.

For engineers reviewing the AD7899BR-3REEL7 datasheet, AD7899BR-3REEL7 pinout, AD7899BR-3REEL7 application, or AD7899BR-3REEL7 equivalent, key selection criteria include bipolar ±2.5 V input range support, ±1.5 LSB INL (B-grade), 77 dB SNR over temperature, parallel 14-bit interface compatibility with 3 V/5 V logic, and SOIC-28 package thermal performance (θ_JA = 95°C/W).

Technical Context

The AD7899BR-3REEL7 implements a laser-trimmed internal clock oscillator (enabling 400 kSPS throughput without external timing components) and supports optional external clocking via CLKIN with 6.5 MHz max frequency. Its track/hold amplifier achieves 500 kHz –0.1 dB full-power bandwidth and 4.5 MHz –3 dB bandwidth, ensuring accurate digitization of signals up to 200 kHz at Nyquist.

Conversion control uses edge-triggered CONVST for hold-mode initiation and dual-function BUSY/EOC signaling. Data output follows standard parallel read protocol with CS/RD strobes, supporting both 3 V and 5 V VDRIVE levels for mixed-voltage system interfacing. Output coding is two's complement for the AD7899-3 variant.

Key Specifications

Pinout & Package

AD7899BR-3REEL7 is housed in a 28-lead Small Outline Integrated Circuit (SOIC) package (package option R-28), with 1.27 mm lead pitch, JEDEC MS-012AC compliant footprint, and θ_JA = 95°C/W thermal resistance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7899AR-3, the AD7899BR-3REEL7 delivers tighter INL for improved absolute accuracy in calibration-sensitive systems; compared with ADS8326IPW, it offers integrated reference and parallel interface but trades off resolution and sampling speed for lower system complexity and broader voltage compatibility.

Availability

AD7899BR-3REEL7 is available at Aetrix Electronics and suitable for industrial process monitoring, automated test equipment, and medical instrumentation requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AD7899BR-3REEL7 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, single-supply SAR ADCs with integrated references and robust input protection-designed specifically for precision data acquisition in electrically noisy, thermally variable, and safety-critical environments.

FAQ

What is the input voltage range supported by the AD7899BR-3REEL7?

The AD7899BR-3REEL7 supports a fixed bipolar analog input range of ±2.5 V on the VINA pin, with VINB typically grounded per the AD7899-3 configuration. This range is factory-set and not software-configurable; it delivers 610.4 µV LSB resolution and two's complement output coding. The device tolerates overvoltage transients from –4 V to +18 V without damage, making it suitable for industrial sensor interfaces where fault conditions may occur.

Does the AD7899BR-3REEL7 require an external reference voltage?

No, the AD7899BR-3REEL7 includes an internal 2.5 V reference with ±20 mV max error over temperature and 25 ppm/°C typical drift. A 0.1 µF capacitor from VREF to AGND suffices for stable operation. However, the VREF pin also accepts an external 2.5 V ±5% reference (e.g., AD780 or REF43) to improve accuracy or synchronize multiple ADCs-this overdrives the internal reference without requiring external switching circuitry.

How does the AD7899BR-3REEL7 interface with a 3 V microcontroller?

The AD7899BR-3REEL7 supports 3 V logic interfacing via its dedicated VDRIVE pin: tie VDRIVE to 3 V ±10%, and the DB0–DB13 outputs, BUSY/EOC, and logic inputs (CS, RD, CONVST, STBY, CLKIN) will operate at 3 V logic levels. This eliminates level shifters while maintaining full timing compliance-including 3 ns minimum data access time at VDRIVE = 5 V and 40 ns at VDRIVE = 3 V-ensuring reliable communication with ARM Cortex-M or similar 3 V MCUs.

What is the power consumption of the AD7899BR-3REEL7 in active and standby modes?

In normal operation, the AD7899BR-3REEL7 draws 16 mA typical (25 mA max) from the 5 V VDD supply, resulting in ~80 mW typical power dissipation. In standby mode (STBY = LOW), supply current drops to 5 µA typical (20 µA max), reducing power to ~100 µW. Wake-up time from standby to first valid conversion is less than 2 µs, enabling aggressive duty-cycling in battery-powered applications without sacrificing responsiveness.

Can the AD7899BR-3REEL7 be used with an external clock source?

Yes, the AD7899BR-3REEL7 accepts an external clock 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, 60/40 duty cycle) instead of its internal oscillator. This allows synchronization to system clocks or jitter-sensitive timing domains. The external clock must start ≥100 ns after CONVST rising edge; conversion still requires exactly 16 clock cycles regardless of source.