Analog Devices Inc. OP37GSZ

Overview

OP37GSZ from Analog Devices is a low-noise, precision, high-speed operational amplifier optimized for closed-loop gains ≥5, featuring 3.0 nV/√Hz input voltage noise density at 1 kHz, 17 V/μs slew rate, and 63 MHz gain-bandwidth product. It delivers ±11.5 V output swing into 2 kΩ with 0.2 mV/°C offset drift, making it ideal for microphone preamplifiers, RIAA phono stages, and high-gain data acquisition signal conditioning.

For engineers reviewing the OP37GSZ datasheet, OP37GSZ pinout, OP37GSZ application, or OP37GSZ equivalent, key selection criteria include guaranteed minimum open-loop gain (700 V/mV), CMRR ≥100 dB over ±11 V common-mode range, PSRR ≤20 mV/V, and compatibility with 8-lead SOIC packaging for surface-mount industrial instrumentation designs.

Technical Context

The OP37GSZ employs a decompensated architecture requiring minimum closed-loop gain of 5 for stability, enabling higher slew rate (17 V/μs) and bandwidth (63 MHz) than unity-gain-stable predecessors like the OP27. Its input stage uses bias-current cancellation to achieve 10 nA typical input bias current while maintaining ultra-low voltage noise.

On-chip zener-zap trimming sets initial offset voltage (≤100 μV max for G-grade), and external 10 kΩ potentiometer adjustment supports ±4 mV fine-tuning without degrading long-term drift (0.4 μV/°C typical). Input protection diodes allow ±0.7 V differential voltage but require external current limiting beyond that threshold.

Key Specifications

Pinout & Package

OP37GSZ is supplied in an 8-lead SOIC (Small Outline Integrated Circuit) package with standard JEDEC MS-012AC footprint and 1.27 mm lead pitch. The package provides creepage/clearance suitable for 150 V working voltage applications and is RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with OP27GSZ and AD825ARZ, OP37GSZ uniquely balances decompensated speed (63 MHz, 17 V/μs) with precision DC performance (100 μV VOS max, 0.4 μV/°C drift), making it optimal for fixed-gain ≥5 signal chains where both bandwidth and low-frequency accuracy are critical.

Availability

OP37GSZ is available at Aetrix Electronics and suitable for microphone preamplifiers, RIAA phono stages, and high-gain data acquisition systems requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for OP37GSZ 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, automotive, and consumer markets since 1965.

The OP37 series belongs to Analog Devices' precision op amp product line, designed specifically for high-gain (>5), low-noise, low-drift instrumentation applications where traditional op amps compromise speed for DC accuracy.

FAQ

What is the minimum stable closed-loop gain for OP37GSZ?

The OP37GSZ is decompensated and requires a minimum closed-loop gain of 5 for stable operation. Attempting unity-gain or G = 2 configurations will cause peaking or oscillation. This design enables its 63 MHz gain-bandwidth product and 17 V/μs slew rate-performance unattainable in unity-gain-stable equivalents like the OP27GSZ. Always verify phase margin using SPICE models when designing at G = 5.

Does OP37GSZ support single-supply operation?

Yes, OP37GSZ supports single-supply operation from +8 V to +36 V. Its input common-mode range extends to within 1.2 V of V– and 1.5 V of V+, and output swings to within 1.5 V of each rail into 2 kΩ. For true rail-to-rail input/output, consider newer precision amplifiers-but OP37GSZ remains viable for industrial sensors with mid-supply biasing and adequate headroom.

How is input offset voltage trimmed in OP37GSZ?

OP37GSZ uses on-chip zener-zap trimming at wafer probe to set initial offset voltage ≤100 μV (G-grade). Pins 1 and 8 provide external adjustment via a 10 kΩ potentiometer, enabling ±4 mV fine-tuning. Critically, this adjustment does not degrade the 0.4 μV/°C typical drift specification-unlike many op amps where nulling increases thermal sensitivity.

What are the absolute maximum ratings for OP37GSZ supply voltage?

OP37GSZ has an absolute maximum supply voltage rating of ±22 V (or 44 V total across V+ and V–). Exceeding this risks junction breakdown. Operating supply should remain within ±4 V to ±18 V for specified performance; at ±18 V, power dissipation reaches 170 mW maximum, requiring attention to PCB copper area and ambient temperature.

Can OP37GSZ drive capacitive loads directly?

OP37GSZ can drive up to 1000 pF capacitive load while maintaining stability and ≤20% overshoot, per datasheet TPC 22. For larger loads (e.g., ADC input capacitors or long cables), isolate with a 50 Ω series resistor placed inside the feedback loop-not at the output-to preserve bandwidth and avoid phase lag. Never use output-series resistance alone without feedback compensation.