Analog Devices Inc. AD7899SRZ-1

Overview

AD7899SRZ-1 from Analog Devices is a 14-bit, 400 kSPS successive-approximation ADC with single 5 V supply operation, ±5 V/±10 V input ranges, internal 2.5 V reference, and high-speed parallel interface. It integrates track/hold amplifier (0.3 µs acquisition), on-chip clock oscillator, and overvoltage protection (±18 V on ±10 V range), enabling precision data acquisition in industrial control and test equipment.

For engineers reviewing the AD7899SRZ-1 datasheet, AD7899SRZ-1 pinout, AD7899SRZ-1 application, or AD7899SRZ-1 equivalent, key selection factors include bipolar input range support, military-grade temperature operation (–55°C to +125°C), 2.2 µs conversion time, and 3 V/5 V logic compatibility via VDRIVE pin.

Technical Context

The AD7899SRZ-1 implements a laser-trimmed internal clock oscillator or accepts external CLKIN (up to 6.5 MHz) for conversion timing control. Its track/hold architecture achieves 500 kHz –0.1 dB full-power bandwidth and 25 ps aperture jitter, supporting accurate digitization of fast-changing analog signals.

Conversion initiation is edge-triggered via CONVST; BUSY/EOC serves dual-mode signaling (BUSY active-high during conversion, EOC pulse-low at completion). Data output uses 14-bit parallel bus (DB0–DB13) with CS/RD handshaking and three-state drivers compatible with both 3 V and 5 V microprocessors.

Key Specifications

Pinout & Package

AD7899SRZ-1 is housed in a 28-lead SOIC package (R-28) with standard 0.3-inch body width and gull-wing leads. Pin layout follows industry-standard dual-in-line configuration with exposed pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7899BR-1, AD7899SRZ-1 trades minor INL degradation for guaranteed operation across –55°C to +125°C, while ADS8505IPFB offers two extra bits at the cost of added external components and reduced speed-making AD7899SRZ-1 optimal for ruggedized, high-throughput 14-bit systems.

Availability

AD7899SRZ-1 is available at Aetrix Electronics and suitable for industrial process monitoring, aerospace flight data acquisition, and automated test equipment requiring stable component supply across extended temperature ranges.

Supply support for AD7899SRZ-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 defense markets.

The AD7899 product line delivers high-speed, low-power, single-supply SAR ADCs with integrated references and robust input protection-designed specifically for demanding data acquisition in harsh environments.

FAQ

What is the operating temperature range of the AD7899SRZ-1?

The AD7899SRZ-1 is rated for operation from –55°C to +125°C, meeting military-grade environmental specifications. This extended range is confirmed in the Ordering Guide and Absolute Maximum Ratings table, where the "S" suffix denotes the military temperature version. The part maintains full performance-including 400 kSPS throughput and ±2 LSB INL-across this entire span, making it suitable for aerospace, defense, and under-hood automotive applications where thermal extremes are expected. AD7899SRZ-1's qualification includes rigorous burn-in and temperature cycling per MIL-STD-883.

Does the AD7899SRZ-1 require an external reference?

No, the AD7899SRZ-1 includes an internal 2.5 V reference with ±20 mV error over temperature, eliminating the need for an external reference in most applications. The VREF pin provides access to this buffered reference and also accepts an external 2.5 V ±5% source to override the internal one-useful when higher initial accuracy or lower drift is required. Reference output impedance is 6 kΩ, so buffering is recommended if driving external circuitry. AD7899SRZ-1's internal reference enables compact, low-cost designs while retaining flexibility for precision upgrades.

How does the AD7899SRZ-1 handle analog input overvoltage conditions?

The AD7899SRZ-1 features built-in overvoltage protection allowing analog inputs to withstand up to ±18 V when configured for the ±10 V range, –9 V to +18 V for ±5 V range, and –1 V to +18 V for unipolar modes-without latch-up or permanent damage. This protection is implemented at the input stage using integrated clamping structures, verified in Absolute Maximum Ratings and confirmed in the Analog Input Section. AD7899SRZ-1's robustness reduces or eliminates the need for external TVS diodes or series resistors in industrial and test equipment where sensor faults or wiring errors may occur.

Can the AD7899SRZ-1 interface directly with a 3 V microprocessor?

Yes, the AD7899SRZ-1 supports direct 3 V logic interfacing via its dedicated VDRIVE pin, which powers the digital I/O circuitry independently from VDD. When VDRIVE is supplied with 3 V ±10%, all digital inputs (CS, RD, CONVST, CLKIN, STBY) recognize 3 V logic levels, and outputs (DB0–DB13, BUSY/EOC) drive to 3 V-compatible thresholds. This eliminates level-shifting components and simplifies integration with modern low-voltage MCUs and FPGAs. AD7899SRZ-1's datasheet explicitly specifies timing and voltage parameters for both 3 V and 5 V VDRIVE operation.

What is the conversion latency and timing behavior of the AD7899SRZ-1?

The AD7899SRZ-1 has a fixed conversion time of 2.2 µs maximum, with BUSY/EOC going high on the rising edge of CONVST and returning low after exactly 2.2 µs (internal clock) or 2.46 µs (6.5 MHz external clock). Track/hold acquisition time is 0.3 µs, meaning the next CONVST must be delayed ≥0.3 µs after BUSY/EOC goes low to ensure full settling. AD7899SRZ-1's timing is deterministic and fully documented in the Timing Characteristics table (Rev. A, p.4), enabling precise synchronization in real-time control loops without software polling overhead.