Analog Devices Inc. LT1112IS8

LT1112IS8 Dual Op Amp Series by Analog Devices A Comprehensive Introduction

The LT1112IS8 from Analog Devices Inc. is a dual general-purpose operational amplifier engineered for applications requiring exceptional precision at an accessible cost point. Featuring two op amp circuits in a space-efficient 8-lead SO (Small Outline) package, the LT1112IS8 addresses the demanding requirements of precision instrumentation, sensor conditioning, low-frequency active filters, and portable systems. As part of the LT1112/LT1114 family, this device pushes the boundaries on input offset voltage and power consumption—making it well-suited for both performance-driven and budget-conscious designs.

Main Attributes and High-Accuracy Benefits of the LT1112IS8 Line

The LT1112IS8 defines a new benchmark in non-chopper dual op amps for low-cost, high-precision applications. Its prime-grade models are specified for maximum input offset voltages as low as 60μV, while basic versions maintain a best-in-class 75μV offset—remarkably low for this device class and package type. Offset voltage drift is controlled to 0.5μV/°C maximum, with input bias currents not exceeding 250pA, ensuring stability and minimal error across varying temperatures.

In noise-critical applications, LT1112IS8 delivers ultra-low noise performance, with a 0.1Hz to 10Hz noise voltage of just 0.3μV peak-to-peak and current noise of 2.2pA peak-to-peak. Each amplifier consumes a maximum of 400μA supply current, supporting battery operation and power-sensitive designs. Common-mode rejection ratio (CMRR) is specified at a minimum of 120dB, and open-loop voltage gain reaches at least one million, suitable for high-accuracy signal amplification.

Additionally, LT1112IS8 offers guaranteed matching specifications between amplifiers, which is essential for differential or instrumentation amplifier configurations. Specifications are tested all the way down to ±1.0V supplies, matching typical portable and low-voltage environments.

Electrical Specifications and Environmental Tolerances of LT1112IS8

LT1112IS8 is rated for absolute maximum supply voltages of ±20V, allowing flexibility across precision and industrial systems. Key operational tolerances include input voltages up to supply rails (±20V), differential input currents of ±10mA, and indefinite output short-circuit duration, supporting robust operation and fault tolerance.

Temperature specifications for LT1112IS8 cover -40°C to +85°C (for industrial grade devices), with wider ranges available on some variants within the LT1112/LT1114 family. Storage conditions safely extend to -65°C to +150°C, and lead soldering temperatures are tolerated up to 300°C for 10 seconds. These parameters ensure reliable integration into most commercial, industrial, and laboratory environments.

Available Packaging Types and Physical Dimensions of LT1112IS8

The LT1112IS8 is delivered in the industry-standard 8-lead SO package, with a narrow body width (0.150 inch). This format facilitates easy surface-mount placement, minimizes board space, and follows standard pinouts compatible with many legacy and current dual op amps. In the broader LT1112/LT1114 family, plastic DIP, CERDIP, and narrow SMT packages are also available—further expanding mechanical design options for system engineers.

The SO package of LT1112IS8 ensures optimized thermal performance and electrical isolation, conforming to mechanical drawing specifications for automated and manual assembly.

Common Use Cases for LT1112IS8 Dual Operational Amplifiers

Engineers can leverage the LT1112IS8 across a spectrum of precision analog functions. Its precision and low offset make it ideal for picoampere/microvolt-level instrumentation, thermocouple and bridge amplifiers, photo-current amplification, and battery-powered systems. The device’s matching specifications are vitally important in designing two- and three-op amp instrumentation amplifiers, where accurate differential amplification and error cancellation are required.

Examples of real-world integration include buffered voltage references powered by low-voltage batteries, low-drift signal conditioning for sensors, and high-impedance analog front-ends. The combination of low supply current and robust rail-to-rail input/output performance enables operation from nearly depleted power sources, such as two AA cells.

Design Insights for Instrumentation and Precision Amplifier Applications Utilizing LT1112IS8

The LT1112IS8 stands out in applications where matched amplifier performance, rather than individual amplifier parameters, dominates system accuracy. In instrumentation amplifiers, for example, the device’s matched offsets and rejection ratios (ΔCMRR and ΔPSRR) ensure that output errors due to amplifier mismatch are minimized, directly impacting precision measurements.

Designers should be aware of input protection diodes within the LT1112IS8, which safeguard the device against large input pulses. For voltage-follower configurations subject to large-signal inputs, it is recommended to use a feedback resistor to limit current through protection paths. The device maintains clean output clipping—without phase reversal—even when input voltages exceed the common-mode range, distinguishing it from competitive models.

Additionally, matching benefits are most pronounced in the quad (LT1114) package, where all inputs are adjacent to supply pins, eliminating input capacitance mismatches that can reduce rejection performance when used with high-impedance sources.

Alternative or Substitute Op Amp Models Comparable to LT1112IS8

For engineers considering alternative devices or needing cross-references for supply chain resilience, several operational amplifiers can function as direct replacements or equivalents for LT1112IS8 in pin compatibility and performance. These include the OP-200, OP-297, and AD706 dual amplifiers, as well as the OP-400, OP-497, and AD704 quad amplifiers for the LT1114 variant. Notably, LT1112IS8 not only matches but in many cases exceeds the precision and cost-performance ratio of these alternatives, particularly in low offset voltage and power consumption.

Conclusion

The LT1112IS8 dual operational amplifier from Analog Devices Inc. delivers a proven combination of ultra-low offset, low noise, and optimized matching—making it a highly attractive choice for engineers and procurement specialists targeting high-precision, battery-powered, and cost-sensitive instrumentation. Its robust electrical and environmental ratings, flexible packages, and best-in-class precision set a new standard for general-purpose op amps in instrument design, sensor interfaces, and active filtering. For applications where accuracy, efficiency, and compactness are decisive, LT1112IS8 provides a reliable path to performance and value.