Analog Devices Inc. AD825ARZ-REEL

Overview

AD825ARZ-REEL from Analog Devices is a high-speed JFET-input operational amplifier optimized for precision signal conditioning in data acquisition and mixed-signal systems. It delivers 44 MHz −3 dB bandwidth, 125 V/µs slew rate, and 12 nV/√Hz input voltage noise at ±15 V supply, with rail-to-rail input capability and no phase reversal-making it ideal for ADC input buffers and photo detector interfaces.

For engineers reviewing the AD825ARZ-REEL datasheet, AD825ARZ-REEL pinout, AD825ARZ-REEL application, or AD825ARZ-REEL equivalent, key selection factors include its ultralow 20 pA input bias current, 50 mA output drive into unlimited capacitive loads, stable performance across ±5 V to ±15 V supplies, and SOIC-8 packaging compatible with high-density PCB layouts.

Technical Context

The AD825ARZ-REEL employs a common-drain/common-base FET input stage followed by a cascoded NPN gain stage and Class AB emitter-follower output buffer. Its internal compensation and bootstrapped output capacitor (CF) enable stable operation driving heavy capacitive loads without external compensation.

This architecture ensures no phase reversal even when inputs exceed supply rails, maintains >70 dB open-loop gain at 1 kΩ load, and sustains 41 MHz bandwidth and 125 V/µs slew rate across −40°C to +85°C operating temperature range with ±5 V or ±15 V dual supplies.

Key Specifications

Pinout & Package

AD825ARZ-REEL is housed in an 8-lead SOIC_N (R-8) package per JEDEC MS-012-AA, with 1.27 mm lead pitch, 5.00 mm × 4.00 mm body size, and exposed pad not present. Pin 1 is NC (no connect), Pin 2 is inverting input (−IN), Pin 3 is noninverting input (+IN), Pin 4 is negative supply (−VS), Pin 5 is NC, Pin 6 is output (OUTPUT), Pin 7 is positive supply (+VS), and Pin 8 is NC.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed JFET op-amp applications.

Compared with OPA656U and ADA4817-1ARMZ, the AD825ARZ-REEL offers optimal balance of 44 MHz bandwidth, 6.5 mA supply current, and SOIC-8 compatibility-making it the preferred choice for cost-sensitive, space-constrained industrial data acquisition where 100+ MSPS isn't required.

Availability

AD825ARZ-REEL is available at Aetrix Electronics and suitable for CCD signal chains, precision ADC front-ends, and photodetector interfaces requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for AD825ARZ-REEL 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.

The AD825 belongs to Analog Devices' precision high-speed op-amp product line, engineered for demanding signal conditioning in test equipment, medical imaging, and industrial automation where dc accuracy and ac fidelity must coexist.

FAQ

What is the maximum capacitive load the AD825ARZ-REEL can drive without external compensation?

The AD825ARZ-REEL is internally compensated to drive unlimited capacitive loads stably, as confirmed in the datasheet's "Driving Capacitive Loads" section and Figure 30–31. This includes direct connection to 400 pF loads with clean pulse response, eliminating need for series isolation resistors in DAC output or filter applications. The internal bootstrapped capacitor CF enables this behavior across all supply voltages and temperatures.

Does the AD825ARZ-REEL support single-supply operation?

The AD825ARZ-REEL is specified for dual-supply operation only (±5 V to ±15 V), with input common-mode range extending to ±13.5 V at ±15 V supplies and ±3.5 V at ±5 V supplies. It does not support true single-supply operation because the input stage requires symmetric rails to maintain bias point and avoid phase reversal-using it with single-ended supplies risks undefined behavior or damage.

What is the purpose of the NC pins (1, 5, 8) on the AD825ARZ-REEL SOIC-8 package?

Pins 1, 5, and 8 on the AD825ARZ-REEL are designated No Connect (NC) per Figure 4 and the Ordering Guide. They are electrically isolated from internal circuitry and serve no functional role. These pins may be left unconnected or grounded solely for mechanical stability or EMI reduction in high-frequency layouts-but grounding them is optional and does not affect electrical performance.

How does the AD825ARZ-REEL achieve no phase reversal when inputs exceed supply rails?

The AD825ARZ-REEL achieves rail-to-rail input tolerance and no phase reversal through its unique common-drain/common-base FET input stage, which prevents latch-up during overvoltage conditions. As described in the "Theory of Operation" section, this architecture allows inputs to swing beyond ±VS without disturbing the internal bias network or causing output polarity inversion-critical for post-multiplexer buffering where channel switching induces transient overdrive.

Is the AD825ARZ-REEL RoHS compliant and what does the "Z" suffix indicate?

Yes, the AD825ARZ-REEL is RoHS compliant, as indicated by the "Z" in the part number per Analog Devices' Ordering Guide. The "Z" suffix denotes lead-free, halogen-free, and RoHS-compliant packaging. The "REEL" suffix specifies 13-inch tape-and-reel packaging (2500 units per reel), suitable for automated SMT assembly in high-volume manufacturing environments.