Analog Devices Inc. LT1637CS8#TRPBF

Overview

LT1637CS8#TRPBF 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–, even on 3V supplies. It delivers 1.1MHz gain-bandwidth, 0.4V/µs slew rate, ±25mA output drive, and shutdown mode reducing supply current to 3µA - ideal for battery-powered sensor conditioning and high-side current sensing in industrial monitoring systems.

For engineers reviewing the LT1637CS8#TRPBF datasheet, LT1637CS8#TRPBF pinout, LT1637CS8#TRPBF application, or LT1637CS8#TRPBF equivalent, key selection criteria include its reverse-supply protection (25V), input common-mode range extending beyond V+, rail-to-rail output swing into 25mA loads, and guaranteed performance over –40°C to 85°C in the SO-8 package.

Technical Context

The LT1637CS8#TRPBF employs a dual-input-stage architecture (NPN + PNP) enabling seamless operation across its full 0V to 44V input common-mode range relative to V–, including voltages exceeding V+. Its Over-The-Top® topology eliminates phase reversal for inputs up to 5V below VEE or 44V above VEE, independent of VCC.

Internal compensation supports stable unity-gain operation into capacitive loads up to 4700pF when using optional 0.22µF + 150Ω output network. Shutdown is activated by pulling SHDN ≥1.2V above V–, forcing output into high-impedance state and reducing quiescent current to ≤3µA while maintaining <0.1nA input bias current.

Key Specifications

Pinout & Package

LT1637CS8#TRPBF is housed in an 8-lead plastic SO (SO-8) package per JEDEC MS-012, with θ_JA = 190°C/W and maximum junction temperature of 150°C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC6081CMS8#PBF and AD8603ARZ-REEL7, the LT1637CS8#TRPBF uniquely combines 44V-over-V– input tolerance, reverse-battery immunity, and shutdown current <3µA - making it irreplaceable in high-voltage, battery-reversal-exposed, or ultra-low-power always-on monitoring nodes.

Availability

LT1637CS8#TRPBF is available at Aetrix Electronics and suitable for battery monitoring, high-side current sensing, Over-The-Top comparator circuits, and portable sensor signal conditioning requiring stable component supply across industrial temperature ranges.

Supply support for LT1637CS8#TRPBF 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 and maintains its legacy precision analog portfolio, emphasizing high-reliability, high-performance signal conditioning ICs for demanding industrial and aerospace applications.

The LT1637 product line was designed specifically for ruggedized, wide-supply, high-common-mode industrial signal acquisition - addressing gaps in micropower op amps unable to handle inputs beyond the supply rails or survive reverse battery conditions.

FAQ

What is the maximum input voltage range supported by the LT1637CS8#TRPBF relative to V–?

The LT1637CS8#TRPBF supports an input common-mode voltage range from 0V to 44V relative to V–, regardless of V+ supply level. This Over-The-Top® capability allows direct connection to signals up to 44V above the negative rail - for example, measuring battery voltage at the positive terminal while powered from a lower-voltage auxiliary rail. The specification is guaranteed across the full –40°C to 85°C operating temperature range.

Does the LT1637CS8#TRPBF require external compensation for driving capacitive loads?

The LT1637CS8#TRPBF is internally compensated for stable operation into ≥200pF. For capacitive loads exceeding 200pF - such as long PCB traces or LCD panel inputs - optional external compensation using a 0.22µF capacitor in series with a 150Ω resistor between OUT and GND is required to maintain stability up to 4700pF. This network must be placed close to the device output pin to minimize parasitic inductance.

How does the shutdown function operate on the LT1637CS8#TRPBF, and what is its leakage behavior?

The LT1637CS8#TRPBF enters shutdown when the SHDN pin is driven ≥1.2V above V–, reducing supply current to ≤3µA and output leakage current to <1µA. Input bias current drops below 0.1nA, preserving high-impedance sensing during sleep. The SHDN pin tolerates voltages up to 32V above V–, enabling direct interface with higher-voltage control logic without level shifters.

Can the LT1637CS8#TRPBF drive a 10kΩ load rail-to-rail on a 3V supply?

Yes - the LT1637CS8#TRPBF delivers true rail-to-rail output swing into 10kΩ loads on 3V supplies: VOH ≥2.94V (no load) and ≥2.25V (5mA source), VOL ≤8mV (no load) and ≤325mV (5mA sink). This performance enables direct interfacing with 3V ADC references or microcontroller GPIOs without level-shifting, maintaining full 3V dynamic range for optimal signal-to-noise ratio.

Is reverse supply protection active in shutdown mode for the LT1637CS8#TRPBF?

Yes - reverse supply protection remains fully active in shutdown mode. When V+ is reversed to –25V relative to V–, the LT1637CS8#TRPBF draws <1nA total supply current, preventing damage or system backfeed. This behavior is inherent to the internal protection architecture and does not depend on SHDN pin state, making it reliable for battery-powered equipment subject to accidental polarity reversal during field maintenance.