Analog Devices Inc. AD648JNZ

Overview

AD648JNZ from Analog Devices is a dual precision, low-power BiFET operational amplifier in an 8-lead plastic mini-DIP (N) package. It delivers 1 MHz unity-gain bandwidth, 1.8 V/µs slew rate, and guaranteed 2 mV max input offset voltage with 20 µV/°C drift over 0°C to 70°C - enabling high-accuracy signal conditioning in battery-powered instrumentation front ends and CMOS DAC buffers.

For engineers reviewing the AD648JNZ datasheet, AD648JNZ pinout, AD648JNZ application, or AD648JNZ equivalent, key selection criteria include its matched-pair laser-trimmed DC performance, ultra-low 400 µA quiescent current per amplifier, JFET-input bias current ≤20 pA (warmed up), and compatibility with ±4.5 V to ±18 V dual supplies.

Technical Context

The AD648JNZ integrates two independent JFET-input op amps on a single monolithic die using ion-implanted FET and laser wafer trimming. Its input stage guarantees low bias current across the full common-mode range (±11 V), while open-loop gain ≥300 V/mV (RL ≥ 10 kΩ) supports high-precision closed-loop configurations.

Designed for dual-supply operation, it achieves 82 dB minimum CMRR (B grade), –120 dB crosstalk at 1 kHz, and 2 µV p-p 0.1 Hz–10 Hz input voltage noise - all while maintaining <400 µA total quiescent current. The device avoids phase reversal under common-mode overvoltage but requires guarding for sub-picoamp leakage control in photodiode preamp layouts.

Key Specifications

Pinout & Package

AD648JNZ is housed in an 8-lead plastic mini-DIP (N-8) package with 0.3-inch body width, 0.1-inch lead pitch, and through-hole mounting. Thermal resistance θ_JA = 165°C/W ensures stable operation at ≤500 mW dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL062CDR and LF442CN, AD648JNZ provides superior DC precision (2 mV vs. 3–5 mV offset), lower bias current (20 pA vs. 25–30 pA), and faster dynamic response (1.8 V/µs vs. 0.4–1.5 V/µs), making it essential for 12-bit+ measurement systems where long-term stability and low-noise signal integrity are non-negotiable.

Availability

AD648JNZ is available at Aetrix Electronics and suitable for precision instrumentation front ends, photodiode preamplifiers, and CMOS DAC output buffering requiring stable component supply across extended production lifecycles.

Supply support for AD648JNZ 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, communications, and automotive markets since 1965.

The AD648 product line delivers dual precision BiFET op amps optimized for low-power, high-DC-accuracy applications including sensor signal chains, portable test equipment, and precision data converters.

FAQ

What is the maximum guaranteed input offset voltage for AD648JNZ at +25°C?

The AD648JNZ has a maximum guaranteed input offset voltage of 2.0 mV at +25°C after five minutes of operation, as specified in the Rev. E datasheet. This value is laser-trimmed during wafer fabrication and applies to the commercial-grade AD648J variant. The AD648JNZ package variant inherits this specification, ensuring predictable DC error in precision buffer and amplifier circuits without requiring external nulling.

Does AD648JNZ support single-supply operation?

AD648JNZ is designed for dual-supply operation (±4.5 V to ±18 V) and does not support true single-supply operation. Its input common-mode range extends from 3 V above the negative supply to 1 V below the positive supply, requiring both rails for proper function. Attempting single-supply use (e.g., 0 V and +15 V) will violate the common-mode input specification and cause phase reversal or output saturation. For single-supply applications, consider purpose-built rail-to-rail op amps instead of AD648JNZ.

What is the thermal resistance (θ_JA) of the AD648JNZ package?

The AD648JNZ uses an 8-lead plastic mini-DIP (N-8) package with a junction-to-ambient thermal resistance (θ_JA) of 165°C/W, as documented in the Absolute Maximum Ratings section of the Rev. E datasheet. This value assumes standard JEDEC test conditions (single-layer board, no copper pour). Designers must limit power dissipation to ≤3 mW per amplifier (6 mW total) to keep junction temperature rise below 1°C - critical for maintaining the 20 µV/°C offset drift specification.

Can AD648JNZ drive capacitive loads directly?

AD648JNZ is characterized to cleanly drive resistive loads up to 10 kΩ and capacitive loads up to 100 pF simultaneously. Driving larger capacitive loads (>100 pF) without isolation resistance risks instability and peaking due to phase margin degradation. For photodiode preamps or DAC buffers with >100 pF capacitance, a series resistor (e.g., 100 Ω) between AD648JNZ output and load is required to maintain stability - as confirmed in the Application Notes section describing Figure 27 and Figure 24 layouts.

Is AD648JNZ pin-compatible with industry-standard dual op amps?

Yes, AD648JNZ uses the standard dual op amp pinout (SOIC-8 / mini-DIP-8) and is explicitly documented as pin-compatible with LF442, TL062, and AD642. This allows direct substitution in existing PCB layouts without modification, provided the design meets AD648JNZ's supply voltage (±4.5 V to ±18 V), temperature (0°C to 70°C), and loading requirements. No PCB changes are required for drop-in replacement in compatible applications.