Analog Devices Inc. AD8513ARZ

Overview

AD8513ARZ from Analog Devices is a quad precision JFET operational amplifier optimized for high-impedance sensor signal conditioning and low-noise current measurement. It delivers 400 μV max offset voltage, 25 pA typical input bias current at ±15 V, 8 nV/√Hz voltage noise at 1 kHz, and 20 V/μs slew rate - enabling accurate photodiode amplification and medical instrumentation front-ends.

For engineers reviewing the AD8513ARZ datasheet, AD8513ARZ pinout, AD8513ARZ application, or AD8513ARZ equivalent, key selection criteria include its 14-pin SOIC_N package, quad-channel architecture with independent inputs/outputs, guaranteed operation from −40°C to +125°C, and compatibility with capacitive loads up to 1000 pF without oscillation.

Technical Context

The AD8513ARZ employs a JFET-input stage to achieve ultra-low input bias current (25 pA typ) and low voltage noise (8 nV/√Hz), making it suitable for high-source-impedance transducer interfaces. Its unity-gain stability, 8 MHz gain bandwidth product, and 52° phase margin ensure robust performance in active filter and precision I-V conversion topologies.

Unlike legacy JFET op-amps, the AD8513ARZ eliminates output phase reversal when input voltages exceed common-mode limits, and supports dual-supply operation from ±5 V to ±15 V with rail-to-rail output swing capability under moderate loads.

Key Specifications

Pinout & Package

AD8513ARZ is housed in a 14-lead narrow SOIC (SOIC_N) package, 8.65 mm × 3.90 mm footprint, 1.75 mm height, with standard JEDEC MS-012AC outline and gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA4141AIDR and LT1028CSW#PBF, AD8513ARZ provides the best balance of low input bias current, low voltage noise, full −40°C to +125°C specification, and guaranteed phase reversal immunity - making it uniquely suited for ruggedized precision analog front-ends.

Availability

AD8513ARZ is available at Aetrix Electronics and suitable for precision current sensing, photodiode amplification, and medical instrumentation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AD8513ARZ 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 AD851x family was designed specifically for precision analog signal chains in instrumentation, test equipment, and sensor interfaces - emphasizing dc accuracy, low noise, and robustness in real-world operating conditions.

FAQ

What is the maximum capacitive load the AD8513ARZ can drive without oscillation?

The AD8513ARZ is unconditionally stable and can drive up to 1000 pF in unity-gain configuration without oscillation. This capability eliminates the need for external isolation resistors in applications such as piezoelectric sensor interfaces or long-cable connections. For loads exceeding 500 pF, adding a snubber network (e.g., 100 Ω + 1 nF) further suppresses overshoot to <3%, preserving signal fidelity in AD8513ARZ-based designs.

Does the AD8513ARZ exhibit phase reversal when input voltages exceed the supply rails?

No, the AD8513ARZ does not suffer from output phase reversal - even when input voltages exceed the maximum common-mode range. This behavior is explicitly guaranteed in the datasheet and verified across −40°C to +125°C. Unlike many older JFET op-amps, AD8513ARZ maintains correct polarity during overvoltage transients, preventing system lockups in AD8513ARZ-based sensor front-ends exposed to ESD or inductive kickback.

What is the typical input bias current of the AD8513ARZ at ±15 V supply?

The typical input bias current of the AD8513ARZ is 25 pA at ±15 V and 25°C, with a maximum of 80 pA across the full −40°C to +125°C temperature range. This ultra-low value enables accurate amplification of signals from high-impedance sources such as photodiodes, pH electrodes, and piezoresistive sensors. The AD8513ARZ maintains this performance without requiring guard traces or active bias cancellation circuits.

Can the AD8513ARZ operate from a single supply?

The AD8513ARZ is specified for dual-supply operation from ±5 V to ±15 V and is not characterized for true single-supply use. While it may function with asymmetric supplies (e.g., +15 V and GND), its input common-mode range extends only to −2.0 V and +2.5 V at ±5 V, and to −13.5 V and +13.0 V at ±15 V - meaning GND lies outside the guaranteed linear input range in most single-supply configurations. For single-rail applications, consider purpose-designed rail-to-rail input op-amps instead of AD8513ARZ.

What grade options are available for the AD8513ARZ, and how do they differ?

The AD8513ARZ is offered in two performance grades: A Grade (max 0.9 mV offset voltage, 1.7 μV/°C TCVOS) and B Grade (max 0.4 mV offset voltage, 0.9 μV/°C TCVOS). Both grades share identical pinout, package, noise, speed, and temperature specifications. The B Grade provides tighter initial offset and lower drift - preferred for high-accuracy applications like calibrated test equipment - while the A Grade offers cost-optimized performance for general-purpose precision signal conditioning using AD8513ARZ.