Analog Devices Inc. AD823AARMZ

Overview

AD823AARMZ from Analog Devices is a dual-channel, JFET-input operational amplifier optimized for precision wideband signal conditioning in single- or dual-supply systems. It delivers 17 MHz −3 dB bandwidth (G = +1), 30 V/µs slew rate, rail-to-rail output swing within 20 mV of rails at light load, and 700 µV max input offset voltage. It serves as a high-fidelity ADC driver and photodiode preamplifier in medical instrumentation and 12–16-bit data acquisition.

For engineers reviewing the AD823AARMZ datasheet, AD823AARMZ pinout, AD823AARMZ application, or AD823AARMZ equivalent, this page provides verified specifications, validated package mapping to MSOP-8, confirmed dual-amplifier circuit role, real-world capacitive load drive capability (500 pF), and two technically documented alternative op amps with explicit functional trade-offs.

Technical Context

The AD823AARMZ implements a voltage-feedback architecture with an N-channel JFET input stage and rail-to-rail bipolar output stage fabricated on Analog Devices' XFCB process. Its input operates down to −0.2 V below −VS and up to +VS − 0.2 V, enabling true single-supply operation from 3 V to 36 V (±1.5 V to ±18 V). Input bias current remains ≤25 pA across temperature and common-mode range.

It achieves 14–19 MHz bandwidth depending on supply (3.3 V to ±15 V), maintains 325 ns settling time to 0.01% (2 V step), and drives linear 40 mA output current within 0.5 V of either rail. The 0.6 pF differential input capacitance and absence of phase inversion up to the supply rails support stable photodiode preamp and active filter designs.

Key Specifications

Pinout & Package

AD823AARMZ is packaged in an 8-lead MSOP (Mini Small Outline Package) with 0.5 mm lead pitch, thermally enhanced for surface-mount assembly in space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD823AARMZ, AD822ARMZ trades 4 MHz bandwidth and 300 µV offset for lower cost, while OPA2134PA sacrifices JFET-level input current and speed for TI's production continuity-but neither offers pin-compatible replacement without layout change.

Availability

AD823AARMZ is available at Aetrix Electronics and suitable for photodiode preamplifiers, active filters, and 12–16-bit data acquisition systems requiring stable component supply, long-term lifecycle assurance, and guaranteed traceable sourcing.

Supply support for AD823AARMZ 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 AD823AARMZ belongs to Analog Devices' precision JFET-input op amp product line, engineered for applications demanding low input bias current, rail-to-rail output, wide bandwidth, and robust capacitive load drive-especially in medical, test, and measurement systems.

FAQ

What supply voltage range does the AD823AARMZ support?

The AD823AARMZ operates from a single supply of 3 V to 36 V or dual supplies of ±1.5 V to ±18 V. At 3.3 V single supply, it maintains 17.3 MHz bandwidth and rail-to-rail output swing from 0.006 V to 3.28 V at ±100 µA load. Its input common-mode range extends to −0.2 V below −VS, enabling true ground-sensing capability in low-voltage systems. This flexibility makes AD823AARMZ suitable for battery-powered and industrial power rail environments.

Does the AD823AARMZ exhibit phase inversion near the supply rails?

No, the AD823AARMZ does not exhibit phase inversion for input voltages up to and including the positive or negative supply rails. Its N-channel JFET input stage remains linear and stable even when driven to +VS or −VS, as confirmed in Figure 39 of the datasheet. This eliminates risk of output polarity reversal during overvoltage transients-a critical reliability feature in photodiode and sensor interface circuits where input signals may approach rail limits. AD823AARMZ maintains correct polarity tracking across its full specified common-mode range.

What is the maximum capacitive load the AD823AARMZ can drive stably?

The AD823AARMZ drives up to 500 pF capacitively in unity-gain configuration (G = +1) without external compensation, as verified in Figure 36 and Table 1. At 470 pF, it achieves ~35° phase margin-sufficient for most direct-drive applications. For loads exceeding 500 pF or higher gains, a series resistor (per Figure 28) restores stability. This capability reduces bill-of-materials count and simplifies layout versus op amps requiring mandatory isolation resistors, making AD823AARMZ especially effective in compact, high-density analog signal chains.

How does the AD823AARMZ perform in photodiode preamplifier circuits?

The AD823AARMZ excels as a photodiode preamplifier due to its 25 pA max input bias current (minimizing dark-current error), 0.6 pF differential input capacitance (preserving bandwidth), and absence of phase inversion. With a 5 pF photodiode and 1.2 pF compensation capacitor, it achieves 2.2 MHz transimpedance bandwidth at 45° phase margin (Figure 45). Its 14 nV/√Hz input voltage noise contributes negligibly when source impedance is <10 kΩ, ensuring high SNR in low-light detection. AD823AARMZ thus delivers both precision DC accuracy and wideband AC response in optical sensing.

Is the AD823AARMZ pin-compatible with other dual op amps in MSOP-8?

The AD823AARMZ uses a standard 8-lead MSOP pinout (OUT1, −IN1, +IN1, −VS, +IN2, −IN2, OUT2, +VS) matching AD822ARMZ and AD820ARMZ. However, pin compatibility does not guarantee functional interchangeability: AD822ARMZ has lower bandwidth (13 MHz) and higher offset (1 mV), while AD820ARMZ is single-channel. No drop-in replacement exists for AD823AARMZ's combination of 17 MHz bandwidth, 25 pA bias current, and 500 pF capacitive load drive in MSOP-8. Layout reuse is possible, but electrical validation is required for any substitution involving AD823AARMZ.