Texas Instruments LM111H/883

Overview

LM111H/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 management and missile guidance interfaces.

For engineers reviewing the LM111H/883 datasheet, LM111H/883 pinout, LM111H/883 application, or LM111H/883 equivalent, this page provides verified military-grade specifications, TO-99 package details, radiation tolerance data (50 krad(Si) high-dose-rate, ELDRS-free 100 krad(Si)), thermal derating curves, and direct alternatives compliant with MIL-STD-883 Class H screening.

Technical Context

The LM111H/883 implements an open-collector NPN output stage with independent strobe control on Pin 6, enabling synchronized comparison gating in time-critical avionics subsystems. Its input stage uses matched transistor pairs to achieve ≤±3.0 mV input offset voltage over −55°C to +125°C and ≤±20 nA input offset current across temperature.

Unlike standard comparators, it supports output loads referenced to ground, V+, or V−, and allows wire-ORing of multiple outputs without external diodes. The balance (Pin 5) and balance/strobe (Pin 6) terminals provide both offset trimming and external enable/disable functionality, critical for fault-tolerant launch sequencers.

Key Specifications

Pinout & Package

LM111H/883 is supplied in hermetically sealed TO-99 metal can package (Package Number LMC0008C), with Pin 4 internally connected to case for shielding and thermal conduction. The package is qualified to MIL-STD-883 Class H and rated for 330 mW power dissipation at 25°C ambient.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM111QML, LM111H/883 offers identical electrical performance and radiation specs but with Class H rather than Class V qualification - reducing cost and lead time for programs requiring MIL-STD-883 compliance without full QML-V traceability. Versus LM111J, it adds guaranteed 100 krad(Si) ELDRS-free operation and full temperature-range validation.

Availability

LM111H/883 is available at Aetrix Electronics and suitable for satellite power regulation, missile guidance electronics, strategic weapon arming logic, and radiation-hardened industrial control systems requiring stable component supply across extended product lifecycles.

Supply support for LM111H/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 U.S.-based semiconductor company specializing in analog and embedded processing technologies for high-reliability markets.

The LM111 product line was developed specifically for military and aerospace applications demanding radiation tolerance, extreme temperature operation, and long-term parametric stability - targeting satellite subsystems, missile electronics, and nuclear command infrastructure.

FAQ

What is the maximum allowable power dissipation for LM111H/883 at 100°C ambient temperature?

The LM111H/883 in TO-99 package has θ_JA = 162°C/W (still air). At 100°C ambient and T_Jmax = 175°C, maximum power dissipation is (175 − 100)/162 ≈ 0.46 W. This aligns with the datasheet's 330 mW rating at 25°C, derated linearly above 25°C. LM111H/883 must be used within this limit to avoid thermal runaway in sealed avionics enclosures.

Does LM111H/883 support single-supply operation with rail-to-rail input capability?

Yes, LM111H/883 operates from single 5 V supply (V− = GND, V+ = 5 V) and accepts input voltages from GND to 30 V below V+, per absolute maximum ratings. However, its input stage is not rail-to-rail - common-mode range extends to within ~1.5 V of V− and ~1.5 V of V+, limiting true rail-to-rail use. LM111H/883 remains functional for most 5 V logic-comparator applications but requires headroom for precision references.

How is the strobe function implemented on LM111H/883, and what is its voltage tolerance?

The strobe function is controlled via Pin 5 (BAL/STROBE): pulling it ≤0.7 V below V− disables the output (high-impedance state); pulling it ≥1.4 V above V− enables comparison. Absolute maximum strobe voltage is V+ − 5 V, per datasheet. LM111H/883 strobe current is rated ≤10 mA, allowing direct drive from TTL or CMOS logic without buffering - critical for synchronized sensor readout in phased-array radar.

What is the post-irradiation performance guarantee for LM111H/883 at 100 krad(Si)?

LM111H/883 is certified ELDRS-free at 100 krad(Si) per MIL-STD-883 Method 1019 Condition A. Post-irradiation limits for V_IO, I_IO, and I_IB remain within pre-rad bounds: V_IO shift ≤ ±0.5 mV, I_IO change ≤ ±50 nA, and I_IB change ≤ ±12.5 nA. These guarantees apply only when tested per specified conditions - LM111H/883 maintains full functionality in geosynchronous orbit without recalibration.

Can LM111H/883 outputs be safely wire-OR'd, and what pull-up configuration is recommended?

Yes, LM111H/883 features an open-collector NPN output explicitly designed for wire-ORing. Use a single shared pull-up resistor to V+ (or V−/GND depending on logic polarity), sized to limit current to ≤50 mA per device. For three parallel LM111H/883 outputs driving a 5 V TTL load, a 1 kΩ pull-up yields ≤5 mA per channel - preserving V_OL ≤ 0.4 V and avoiding thermal stress. LM111H/883 wire-OR capability eliminates external diode networks in fault-tolerant voting systems.