Analog Devices Inc. LT1637IMS8#PBF

Overview

LT1637IMS8#PBF from Analog Devices (formerly Linear Technology) is a micropower, rail-to-rail input/output operational amplifier with Over-The-Top® input stage enabling operation with inputs up to 44V above V– and ≥3V below V+, ±25mA input fault tolerance, 25mA output drive, and shutdown capability reducing quiescent current to 3µA. It operates from 2.7V to 44V total supply and is specified over –40°C to 85°C for industrial applications including battery monitoring and high-side current sensing.

For engineers reviewing the LT1637IMS8#PBF datasheet, LT1637IMS8#PBF pinout, LT1637IMS8#PBF application, or LT1637IMS8#PBF equivalent, key selection criteria include its reverse-battery protection (25V), input common-mode range extending beyond V+, rail-to-rail output swing into 25mA loads, and guaranteed performance on 3V/5V/±15V supplies without external compensation for ≤200pF loads.

Technical Context

The LT1637IMS8#PBF integrates dual complementary input stages (NPN and PNP) enabling seamless operation across –15V to +44V common-mode voltage relative to V–, with no phase reversal for inputs 5V below VEE or 44V above VEE. Its Over-The-Top architecture allows direct sensing of voltages exceeding the positive rail-critical for high-side current monitoring in automotive and industrial power systems.

Internal compensation ensures stability driving ≥200pF capacitive loads; optional 0.22µF + 150Ω network extends stable operation to 4700pF. Shutdown control via SHDN pin (operable up to 32V above V–) reduces supply current to 3µA while maintaining high-impedance output and sub-nA input bias current even under extreme common-mode conditions.

Key Specifications

Pinout & Package

LT1637IMS8#PBF is housed in an 8-lead MSOP package (3mm × 3mm × 0.8mm), optimized for space-constrained industrial and portable designs. Thermal resistance θ_JA = 250°C/W reflects compact thermal path design requiring minimal PCB copper area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LT1490AIMS8#PBF and ADA4091-2ARMZ, the LT1637IMS8#PBF uniquely combines 44V Over-The-Top input operation, 25mA output drive, and shutdown in a micropower package-making it irreplaceable for high-side current sensing in 12–48V industrial systems requiring both robustness and low standby power.

Availability

LT1637IMS8#PBF is available at Aetrix Electronics and suitable for battery monitoring, high-side current sensing, and Over-The-Top comparator applications requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for LT1637IMS8#PBF 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 acquired Linear Technology in 2017, inheriting its legacy of high-performance analog ICs for precision, power, and signal integrity applications.

The LT1637IMS8#PBF belongs to Linear's Over-The-Top® op amp family, engineered specifically for high-voltage industrial sensing where inputs exceed the positive supply-enabling simplified, cost-effective high-side current and voltage monitoring.

FAQ

What is the maximum input common-mode voltage for LT1637IMS8#PBF when operating on a 3V supply?

The LT1637IMS8#PBF supports an input common-mode voltage range from –0.4V to 44V relative to V–, regardless of supply voltage. On a 3V supply (V+ = 3V, V– = 0V), this means inputs can extend from –0.4V to 44V-enabling direct sensing of voltages far above the 3V rail, such as 24V or 48V bus lines, without external level-shifting circuitry. This behavior is enabled by its Over-The-Top® input architecture.

Does LT1637IMS8#PBF require external compensation for driving capacitive loads?

The LT1637IMS8#PBF is internally compensated and stable driving ≥200pF capacitive loads under all output conditions. For loads exceeding 200pF-up to 4700pF-a simple external network consisting of a 0.22µF capacitor in series with a 150Ω resistor connected from OUT to ground restores full stability and phase margin. This compensation is optional and only needed for large cable capacitances or heavy capacitive filtering in sensor interfaces.

How does the shutdown feature of LT1637IMS8#PBF affect output state and leakage?

When the SHDN pin of LT1637IMS8#PBF is pulled ≥1.2V above V–, the amplifier enters shutdown mode: supply current drops to ≤3µA, output becomes high-impedance (leakage <1µA), and input bias current falls below 0.1nA-even with inputs at 44V above V–. The output does not short or clamp; it floats, preserving system isolation. Recovery time is 45µs (t_ON) with full rail-to-rail functionality restored.

Can LT1637IMS8#PBF be used in split-supply configurations like ±15V?

Yes, the LT1637IMS8#PBF is fully specified for split-supply operation including ±15V and ±22V. Its absolute maximum ratings allow total supply voltage up to 44V, and electrical characteristics-including input offset voltage (≤350µV), CMRR (≥110dB), and output swing (±14.9V)-are guaranteed across –40°C to 85°C under ±15V conditions. Reverse supply protection applies independently to each rail.

What package type and footprint does LT1637IMS8#PBF use, and are there thermal considerations?

The LT1637IMS8#PBF uses an 8-lead MSOP package (3mm × 3mm × 0.8mm) with exposed pad connected to V–. Its junction-to-ambient thermal resistance is θ_JA = 250°C/W, indicating moderate self-heating under full 25mA output drive. For continuous high-current operation, designers should provide ≥100mm² of 2-oz copper connected to the exposed pad and V– plane to maintain junction temperature within the –40°C to 85°C operating range.