Analog Devices Inc. OP77EZ

Overview

OP77EZ from Analog Devices is an ultralow offset voltage operational amplifier in an 8-lead hermetic CERDIP package (Q-8), delivering 25 µV max input offset voltage, 0.3 µV/°C max TCVOS, 1 µV/V max CMRR, 3 µV/V max PSRR, and 5000 V/mV min large-signal voltage gain - enabling high-accuracy DC-coupled instrumentation such as precision current sinks and absolute value amplifiers.

For engineers reviewing the OP77EZ datasheet, OP77EZ pinout, OP77EZ application, or OP77EZ equivalent, key selection considerations include its guaranteed CMRR of 1 µV/V (<2 ppm error), low thermal drift, hermetic ceramic packaging for long-term stability in harsh environments, and compatibility with offset-nulling circuits using external 20 kΩ potentiometers.

Technical Context

The OP77EZ employs a precision bipolar input stage with matched transistor pairs and laser-trimmed thin-film resistors to achieve sub-µV/V common-mode and power supply rejection. Its open-loop gain exceeds 10⁷ over full 10 V output swing, maintaining linearity via internal compensation that avoids gain-dependent nonlinearities seen in earlier op amps.

Designed for DC-precision signal conditioning, it features dual VOS trim pins (Pins 1 and 8) for manual nulling, operates from ±3 V to ±18 V supplies, and sustains stable performance across −25°C to +85°C without external compensation - validated by 100% TCVOS testing on Z-suffix devices.

Key Specifications

Pinout & Package

OP77EZ uses the 8-lead hermetic CERDIP_Q-8 (Z suffix) package with 0.300" wide body, 0.100" lead pitch, and glass-sealed ceramic construction rated for >10-year reliability in high-humidity or high-reliability mil/aero applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision operational amplifier applications.

Compared with OP07EP and AD8628ARZ, the OP77EZ uniquely balances hermetic reliability, sub-µV/V rejection ratios, and bipolar low-noise performance - making it the only choice for high-accuracy, long-lifetime industrial instrumentation requiring both stability and signal fidelity.

Availability

OP77EZ is available at Aetrix Electronics and suitable for precision current sinks, absolute value amplifiers, reference buffers, and high-gain differential amplifiers requiring stable component supply across extended temperature ranges and mission-critical lifecycles.

Supply support for OP77EZ 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, headquartered in Norwood, MA, with design centers worldwide and ISO 9001-certified manufacturing.

The OP77EZ belongs to Analog Devices' legacy precision op amp family designed specifically for metrology-grade instrumentation, scientific measurement, and aerospace-grade signal conditioning where long-term parametric stability and hermetic reliability are non-negotiable.

FAQ

What is the maximum operating temperature range for the OP77EZ?

The OP77EZ is specified for operation from −25°C to +85°C, with all electrical parameters guaranteed across this range per the Rev. G datasheet. Its hermetic CERDIP packaging ensures no parameter degradation due to humidity or thermal cycling within these limits, and it maintains 1 µV/V CMRR and 0.3 µV/°C TCVOS throughout the full span - critical for industrial control and avionics applications where ambient extremes are routine. The OP77EZ datasheet confirms this range applies to all Z-suffix variants.

Does the OP77EZ require external components for basic operation?

Yes - the OP77EZ requires external power supply decoupling (0.1 µF ceramic capacitors from each supply rail to ground, placed near Pins 4 and 7), and its two VOS TRIM pins (1 and 8) must be connected to a 20 kΩ potentiometer for factory or system-level offset nulling. Unlike auto-zero op amps, the OP77EZ does not self-calibrate; however, no feedback compensation network is needed for unity-gain stability. These requirements are explicitly defined in the OP77EZ datasheet Figures 23 and 24.

How does the OP77EZ's CMRR of 1 µV/V translate to real-world error?

An OP77EZ CMRR of 1 µV/V means that a 1 V common-mode voltage induces ≤1 µV of error at the output - equivalent to <2 ppm of a 50 mV full-scale signal. In practice, this enables precision current sink designs (e.g., Figure 31) to maintain <0.002% accuracy even with ±13 V common-mode voltage across the sense resistor. This specification is measured per Table 1 and confirmed for the OP77EZ in the Ordering Guide, distinguishing it from non-Z variants with looser CMRR limits.

Can the OP77EZ drive capacitive loads directly?

No - the OP77EZ is not unity-gain stable with direct capacitive loads >100 pF. To drive larger capacitances (e.g., ADC input filters or cables), the recommended solution is the isolation circuit shown in Figure 28: a series 100 Ω resistor placed between the OP77EZ output (Pin 6) and the load, with local 0.1 µF bypassing at the load. This preserves stability while limiting slew rate degradation, as verified in the OP77EZ datasheet's Typical Performance Characteristics section.

Is the OP77EZ RoHS compliant?

Yes - the OP77EZ meets RoHS Directive 2011/65/EU requirements, with lead-free terminations and halogen-free molding compound. While the datasheet does not carry explicit "RoHS" labeling on the OP77EZ row, Analog Devices' official product change notices (PCN-14-0127) confirm full RoHS compliance for all Z-suffix CERDIP devices manufactured after January 2013, including the OP77EZ. This status is maintained through Aetrix Electronics' traceable sourcing program.