Texas Instruments INA118PB

Overview

INA118PB from Texas Instruments is a precision, low-power instrumentation amplifier designed for high-accuracy signal conditioning in sensor front-ends. It delivers 50 µV maximum input offset voltage, 0.5 µV/°C max drift, and 110 dB minimum CMR at G = 1000, operating from ±2.25 V to ±18 V supplies with only 350 µA quiescent current - making it ideal for battery-powered pressure transmitters and industrial analog input modules.

For engineers reviewing the INA118PB datasheet, INA118PB pinout, INA118PB application, or INA118PB equivalent, key selection considerations include its laser-trimmed gain-setting architecture (G = 1 + 50 kΩ/R_G), ±40 V input overvoltage protection, 70 kHz bandwidth at G = 100, and verified performance across –40°C to +85°C in both PDIP and SOIC packages.

Technical Context

The INA118PB uses a three-op-amp topology with JFET-input stages and internal 25 kΩ/40 kΩ resistor networks to achieve precise gain control and high common-mode rejection. Its current-feedback input circuitry enables stable wideband operation up to 800 kHz at G = 1 while maintaining low noise (10 nV/√Hz at 1 kHz) and robust input protection.

Gain is set by a single external resistor (RG) between pins 1 and 8, directly determining amplification via G = 1 + 50 kΩ/R_G. Input common-mode range extends from (V–) + 2 V to (V+) – 2 V, and output swing reaches (V+) – 0.8 V / (V–) + 0.35 V under 10 kΩ load - enabling reliable operation in single-supply (4.5 V to 36 V) and dual-supply configurations.

Key Specifications

Pinout & Package

INA118PB is available in 8-pin plastic DIP (PDIP) and SOIC (SO-8) packages. Both variants share identical pin functions and spacing per JEDEC MS-012 and MO-153 standards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA118PB, INA828 offers superior noise and CMR for precision industrial sensing, while INA333 trades supply flexibility for ultra-low power in portable medical devices - neither is a drop-in replacement outside their specified operating conditions.

Availability

INA118PB is available at Aetrix Electronics and suitable for pressure transmitter design, temperature transmitter calibration, and electrocardiogram (ECG) front-end development requiring stable component supply across extended production lifecycles.

Supply support for INA118PB 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

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in precision signal chain components.

The INA118PB belongs to TI's precision instrumentation amplifier product line, engineered specifically for high-accuracy, low-power sensor signal conditioning in industrial process control, medical diagnostics, and test equipment.

FAQ

What is the maximum gain achievable with the INA118PB?

The INA118PB supports gains from 1 to 10,000 using the external resistor RG per the equation G = 1 + 50 kΩ/R_G. At G = 10,000, RG = 5 Ω - requiring careful layout to minimize parasitic resistance. The INA118PB maintains 70 kHz bandwidth at G = 100 and 7 kHz at G = 1000, with gain error ≤1% at maximum gain.

Does the INA118PB require external components for basic operation?

Yes - the INA118PB requires an external gain-setting resistor (RG) between pins 1 and 8 to define amplification. For stable operation, 0.1 µF decoupling capacitors on V+ and V– pins are recommended. The Ref pin must be driven by a low-impedance source (e.g., ground or DAC output) to preserve CMR; a series resistance >12 Ω degrades CMR to ~80 dB.

Can the INA118PB operate from a single 5-V supply?

Yes - the INA118PB operates with V+ = 5 V and V– = 0 V. In this configuration, the linear input common-mode range is 0.2 V to 4.8 V, and output swing reaches 60 mV to 2 V (typical). The device maintains 350 µA quiescent current and 110 dB CMR at G = 1000, making it viable for low-voltage portable instrumentation where the INA118PB's ±40 V input protection remains active even with unpowered supplies.

How does the INA118PB handle input overvoltage conditions?

The INA118PB incorporates JFET-based input protection that withstands ±40 V applied to either input - even with supplies disconnected. During overload, internal circuitry limits input current to ~6 mA, preventing damage to the front-end amplifiers. This protection is intrinsic and requires no external components, unlike discrete solutions that add noise and reduce bandwidth.

What is the temperature range specification for the INA118PB?

The INA118PB is specified for operation from –40°C to +85°C ambient temperature. All key parameters - including offset voltage (±50 µV max), drift (0.5 µV/°C max), CMR (110 dB min at G = 1000), and quiescent current (±350 µA) - are guaranteed across this full industrial temperature range, ensuring reliability in factory-floor and outdoor deployed systems.