Analog Devices Inc. LT1168CS8#TRPBF

Overview

LT1168CS8#TRPBF from Analog Devices (acquired Linear Technology) is a micropower, laser-trimmed precision instrumentation amplifier requiring only one external resistor to set gains from 1 to 10,000. It delivers 10nV/√Hz input voltage noise at 1kHz, 40µV max input offset voltage, and 90dB CMRR at G=1 while consuming just 530µA max supply current across ±2.3V to ±18V supplies - ideal for high-accuracy bridge sensor conditioning in portable medical devices and industrial weigh scales.

For engineers reviewing the LT1168CS8#TRPBF datasheet, LT1168CS8#TRPBF pinout, LT1168CS8#TRPBF application, or LT1168CS8#TRPBF equivalent, key selection criteria include its single-resistor gain programming, 0.4% max gain error at G=10, 20ppm max gain nonlinearity, ESD-hardened inputs (13kV HBM), and IEC 1000-4-2 Level 4 compliance with two 5kΩ external resistors.

Technical Context

The LT1168CS8#TRPBF implements a three-op-amp topology with laser-trimmed 24.7kΩ internal resistors (R1/R2) and superbeta NPN input transistors (Q1/Q2), enabling picoampere bias currents (250pA max) and precise gain accuracy via RG = 49.4kΩ/(G−1). Its transconductance-scaling architecture maintains bandwidth stability across gain settings - 400kHz at G=1, 1kHz at G=1000 - without proportional roll-off.

Input common-mode range extends to within 1.4V of the positive rail and 1.9V of the negative rail at G=1, shrinking predictably with gain due to IR drop across R1/R2. The REF pin (Pin 5) establishes output reference level, with series resistance >6Ω degrading CMRR to 80dB; buffered REF is recommended for single-supply operation.

Key Specifications

Pinout & Package

LT1168CS8#TRPBF is housed in an 8-lead plastic SOIC (S8) package, 3.9mm × 4.9mm footprint, 1.27mm pitch, RoHS-compliant and lead-free (#PBF).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD620ARZ and INA128UA, LT1168CS8#TRPBF offers superior micropower operation (530µA vs >1mA), guaranteed IEC 1000-4-2 Level 4 compliance, and tighter gain accuracy - making it optimal for next-generation portable and industrial sensor nodes demanding long life and robust EMC.

Availability

LT1168CS8#TRPBF is available at Aetrix Electronics and suitable for bridge amplifiers, strain gauge interfaces, and medical instrumentation requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LT1168CS8#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, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing technologies, serving industrial, automotive, communications, and healthcare markets.

The LT1168CS8#TRPBF belongs to ADI's precision instrumentation amplifier product line, designed specifically for high-accuracy, low-power sensor signal conditioning in harsh electromagnetic environments and battery-operated equipment.

FAQ

What is the maximum gain achievable with LT1168CS8#TRPBF?

The LT1168CS8#TRPBF supports gains from 1 to 10,000 using a single external resistor RG, calculated as G = 1 + (49.4kΩ/RG). At G=10,000, RG = 4.94Ω (standard 1% value 4.99Ω yields G≈9980). The LT1168CS8#TRPBF maintains 20ppm gain nonlinearity at G=10 and 40ppm at G=1000 when loaded with RL ≥2kΩ.

Does LT1168CS8#TRPBF require external components for basic operation?

Yes - the LT1168CS8#TRPBF requires only one external resistor (RG) between Pins 1 and 8 to set gain; no additional capacitors, trim pots, or compensation networks are needed for stable operation. For IEC 1000-4-2 Level 4 compliance, two 5kΩ resistors must be added between each input and ground, as specified in the LT1168CS8#TRPBF datasheet.

Can LT1168CS8#TRPBF operate from a single supply?

Yes - the LT1168CS8#TRPBF supports single-supply operation from +4.6V to +36V (±2.3V to ±18V dual equivalent). For optimal performance, the REF pin (Pin 5) must be biased above the negative rail (e.g., to VCC/2), and one input should remain ≥2.5V above ground. The LT1168CS8#TRPBF input common-mode range at G=1 extends from –VS+1.9V to +VS–1.4V.

What is the input bias current specification for LT1168CS8#TRPBF?

The LT1168CS8#TRPBF features 250pA maximum input bias current, achieved via superbeta NPN input transistors and laser-trimmed current sources. This ultra-low bias enables accurate amplification of high-impedance sources (e.g., >100MΩ thermistors or piezoresistive sensors) without introducing significant offset voltage errors - a key advantage over FET-input alternatives with higher 1/f noise.

How does LT1168CS8#TRPBF handle capacitive loads on its output?

The LT1168CS8#TRPBF is internally compensated to drive capacitive loads up to 1000pF in any gain configuration without oscillation or overshoot. This eliminates the need for series isolation resistors typically required with op-amps driving ADC inputs or long PCB traces. Stability is verified per Figure 16 in the LT1168CS8#TRPBF datasheet, showing <5% overshoot at 1000pF with G=1 to G=1000.