Texas Instruments LM111J/883

Overview

LM111J/883 from Texas Instruments is a radiation-hardened voltage comparator designed for high-reliability aerospace and defense systems. It delivers 200 nA max input bias current, ±30 V differential input range, 50 mA output sink capability, and operates from single 5V to dual ±15V supplies. Its strobe function, offset null capability, and ground-isolated inputs/outputs enable use in precision threshold detection within satellite power sequencing and missile guidance analog signal chains.

For engineers reviewing the LM111J/883 datasheet, LM111J/883 pinout, LM111J/883 application, or LM111J/883 equivalent, this device is selected for radiation-tolerant comparator functions requiring wide supply range, TTL/DTL/RTL-compatible output drive, and operation across –55°C to +125°C with MIL-STD-883 Class B screening.

Technical Context

The LM111J/883 implements an open-collector NPN output stage with internal strobe control and balance terminals for offset adjustment. Its input stage uses matched transistor pairs to achieve low input offset voltage (±3.0 mV) and ultra-low input bias current (≤150 nA over temperature), enabling high-impedance sensing without loading source circuits.

It supports three supply configurations: single-ended (5V to ground), split-rail (±15V), and asymmetric rails (e.g., +29.5V/–0.5V). The output can switch loads referenced to V+, ground, or V–, and multiple comparators may be wire-OR'ed via their collector outputs.

Key Specifications

Pinout & Package

LM111J/883 is supplied in an 8-pin TO-99 metal can package (Package Number LMC0008C), with Pin 4 internally connected to the case for thermal and EMI grounding. The package provides hermetic sealing and radiation tolerance essential for space-grade applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage comparator applications.

Compared with LM111QML, LM111J/883 offers identical radiation hardness and temperature range but with Class B (not Class V) screening-making it appropriate for non-flight subsystems. Versus LM111H/883, it adds guaranteed ELDRS-free performance and extended cold-temperature operation, critical for orbital deployment.

Availability

LM111J/883 is available at Aetrix Electronics and suitable for satellite power sequencing, missile guidance analog monitoring, and radiation-tolerant test equipment requiring stable component supply across extended lifecycle programs.

Supply support for LM111J/883 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 heritage in high-reliability military and space-grade components.

The LM111 product line was developed specifically for radiation-hardened analog signal conditioning in mission-critical aerospace systems, emphasizing parametric stability under extreme thermal and ionizing radiation stress.

FAQ

What is the maximum allowable differential input voltage for LM111J/883?

The LM111J/883 supports a differential input voltage range of ±30 V, as specified in Absolute Maximum Ratings. This allows direct comparison of signals referenced to different supply rails or high-voltage sensor outputs without external attenuation, provided common-mode voltage remains within limits (±15 V typical, up to ±28 V depending on supply configuration).

Does LM111J/883 require external pull-up resistors on its output?

Yes, LM111J/883 features an open-collector NPN output (Pin 6) and requires an external pull-up resistor to V+ or another logic rail. Typical values range from 1 kΩ to 10 kΩ depending on speed and load requirements. This architecture enables wire-OR'ing of multiple comparators and flexible logic-level translation.

How is the strobe function implemented on LM111J/883?

The strobe function is accessed via Pin 5 (Balance/Strobe). When pulled low, it disables the output transistor, forcing the collector into high-impedance state regardless of input conditions. This allows synchronized sampling or blanking during critical intervals, such as ADC conversion windows or reset phases in guidance control loops.

What is the purpose of Pin 4 on LM111J/883?

Pin 4 is internally connected to the TO-99 metal can case. It serves as a thermal conduction path and EMI shield reference point. TI recommends connecting Pin 4 to system ground or chassis ground to minimize noise coupling and improve thermal dissipation, especially in high-density or high-radiation environments where parasitic coupling must be minimized.

Can LM111J/883 operate from a single 5V supply?

Yes, LM111J/883 is explicitly characterized for single 5V operation per its datasheet features. With V+ = 5V and V– = ground, it maintains full functionality including input common-mode range (0 V to 3.5 V), output saturation voltage (≤0.4 V at 8 mA), and strobe/offset null capabilities-making it compatible with modern low-voltage digital systems while retaining radiation tolerance.