Analog Devices Inc. AD8620ARZ

Overview

AD8620ARZ from Analog Devices is a dual, precision JFET-input operational amplifier optimized for high-speed, low-noise, low-input-bias-current applications. It delivers 25 MHz gain bandwidth, 50 V/μs slew rate, 6 nV/√Hz voltage noise density at 1 kHz, ≤150 μV max offset voltage (B grade), and operates from ±5 V to ±13 V supplies across −40°C to +125°C. It is used in photodiode amplifiers, fast precision integrators, and high-performance audio signal conditioning.

For engineers reviewing the AD8620ARZ datasheet, AD8620ARZ pinout, AD8620ARZ application, or AD8620ARZ equivalent, key selection criteria include input bias current stability over temperature, capacitive load drive capability (>1 nF without compensation), settling time to 0.01% (≤600 ns), and rail-to-rail output swing (±11.75 V @ ±13 V, 1 kΩ).

Technical Context

The AD8620ARZ employs Analog Devices' XFCB dielectrically isolated process with N-channel JFET inputs and thin-film resistors, enabling ultralow input bias current (<10 pA typ at 25°C, <2.5 nA max at +125°C) and precise offset trimming. Its architecture ensures no phase reversal under overvoltage conditions and stable operation with >1000 pF capacitive loads in unity-gain noninverting configuration.

It features dual independent amplifiers in an 8-lead SOIC_N package, each with fully differential input stage, high CMRR (95 dB min), PSRR (100 dB min), and large-signal voltage gain ≥100 V/mV. Output drives ±45 mA into 10 V swing and settles within 600 ns for a 10 V step at AV = +1.

Key Specifications

Pinout & Package

The AD8620ARZ is housed in an 8-lead narrow SOIC_N (R-8) package with standard JEDEC outline, thermal resistance θJA = 158°C/W, and RoHS-compliant lead finish.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual JFET op amp applications.

Compared with OPA211IDR and LT1028CS8#PBF, the AD8620ARZ uniquely balances femtoamp-level input bias current stability across −40°C to +125°C, 1000 pF capacitive load immunity, and 25 MHz bandwidth - making it the only option qualified for ruggedized, high-impedance, wide-temperature instrumentation.

Availability

AD8620ARZ is available at Aetrix Electronics and suitable for photodiode amplification, ATE signal conditioning, and fast precision integrators requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for AD8620ARZ 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 AD8620ARZ belongs to the AD8610/AD8620 precision JFET op amp family, engineered for applications demanding ultralow input bias current, wide bandwidth, and exceptional DC precision in harsh thermal environments.

FAQ

What is the maximum capacitive load the AD8620ARZ can drive without external compensation?

The AD8620ARZ is stable driving >1000 pF in unity-gain noninverting configuration per the datasheet. At ±5 V supply, it safely drives up to 10 nF; at ±13 V, it handles ≥2 μF with controlled overshoot. This eliminates need for series isolation resistors in anti-aliasing or output filtering applications - a key advantage over legacy JFET op amps like OPA627.

Does the AD8620ARZ exhibit phase reversal when inputs exceed common-mode range?

No. The AD8620ARZ is specifically designed to prevent phase reversal under overvoltage conditions - confirmed in Figure 34 and Functional Description section. When either input is driven beyond the common-mode range (e.g., below V– or above V+), the output remains monotonic and does not invert polarity, avoiding catastrophic failure in servo loops or feedback-critical systems.

What is the input bias current specification for AD8620ARZ over full temperature range?

The AD8620ARZ guarantees input bias current ≤2.5 nA maximum across −40°C to +125°C (Table 1, Electrical Specifications). At 25°C, it is ≤10 pA typical. This extreme stability - unlike many JFET amplifiers whose IB doubles every 10°C - makes it reliable for high-impedance sensor front-ends in uncooled industrial enclosures.

How does the AD8620ARZ compare to AD8610 in pin compatibility and performance?

The AD8620ARZ is a dual-amplifier version in 8-lead SOIC_N; the AD8610 is single-channel in same package footprint. They share identical electrical specs (GBW, SR, noise, offset), but AD8620ARZ pins 1–4 and 5–8 map to two independent amplifiers (OUTA/–INA/+INA/V– and +INB/–INB/OUTB/V+). No PCB redesign is needed when upgrading from AD8610 to dual-channel use - simply route second channel signals to Pins 5–7.

Is AD8620ARZ suitable for driving SAR ADC inputs in high-speed data acquisition systems?

Yes. With 600 ns settling to 0.01% for a 10 V step and ±45 mA output drive, the AD8620ARZ cleanly buffers DAC outputs and drives multiplexed SAR ADC inputs (e.g., AD7960) without track-and-hold droop or distortion. Its low 6 nV/√Hz noise and 25 MHz GBW preserve ENOB in 16-bit+ systems operating up to 1 MSPS.