Texas Instruments LM185WG-1.2/883

Overview

LM185WG-1.2/883 from Texas Instruments is a radiation-qualified, 2-terminal micropower band-gap voltage reference diode delivering 1.223 V to 1.247 V reverse breakdown at 10 µA, with ≤1 Ω typical dynamic impedance and ±50 ppm/°C temperature coefficient across −55°C to +125°C. It operates over 10 µA–20 mA current range and is used in precision analog circuits requiring long-term stability under extreme environmental stress, such as space-grade instrumentation and military avionics.

For engineers reviewing the LM185WG-1.2/883 datasheet, LM185WG-1.2/883 pinout, LM185WG-1.2/883 application, or LM185WG-1.2/883 equivalent, this device serves as a low-noise, radiation-hardened reference for battery-powered thermometers, cold-junction compensators, and high-reliability 1.2 V calibration sources where supply current must remain below 30 µA and post-irradiation drift must stay within ±3% after 100 krad(Si).

Technical Context

The LM185WG-1.2/883 implements a band-gap reference architecture using only transistors and resistors-no capacitors or active compensation-enabling intrinsic low noise and excellent long-term stability. Its on-chip trimming achieves tight initial tolerance without external adjustment.

Designed for MIL-STD-883 Class B qualification, it undergoes full Group A testing across −55°C, 25°C, and +125°C, including functional, dynamic, and settling time validation. Radiation hardness is assured per Method 1019 at 100 krad(Si), with low-dose-rate testing performed at 10 mrad/s.

Key Specifications

Pinout & Package

Ceramic Flatpack (CFP), 10-pin, hermetically sealed package per MIL-PRF-38535; 2.33 mm max height, NAC0010A outline; lead 1 identified by notch or tab; RoHS-exempt, non-lead-finish construction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM185H-1.2/883, the LM185WG-1.2/883 offers superior thermal performance (θJA = 100°C/W) and hermetic reliability in compact CFP form; versus REF102CM, it trades pin count and flexibility for guaranteed survivability in nuclear and space radiation environments.

Availability

LM185WG-1.2/883 is available at Aetrix Electronics and suitable for spacecraft power monitors, military battery gauges, centigrade thermometers, and micropower cold-junction compensators requiring stable component supply under extended temperature and radiation stress.

Supply support for LM185WG-1.2/883 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, embedded processing, and high-reliability components for aerospace, defense, and industrial markets.

The LM185 family was developed specifically for military and space applications requiring ultra-stable, low-power voltage references with proven radiation tolerance and extended temperature operation.

FAQ

What is the maximum radiation dose the LM185WG-1.2/883 is qualified for?

The LM185WG-1.2/883 is radiation-qualified to 100 krad(Si) total ionizing dose per MIL-STD-883 Method 1019, with post-irradiation testing confirming ≤±3% change in reverse breakdown voltage at 10 µA. This rating applies to both biased and unbiased operation under low-dose-rate conditions (10 mrad/s), making LM185WG-1.2/883 suitable for low-Earth orbit missions and nuclear facility instrumentation where cumulative radiation exposure is critical.

Does the LM185WG-1.2/883 require external capacitors for stability?

No, the LM185WG-1.2/883 does not require external capacitors for stability. Its internal band-gap architecture and careful layout make it exceptionally tolerant of capacitive loading-functional up to 10 µF without oscillation or phase margin loss. This eliminates the need for board space and bill-of-materials overhead in compact, high-reliability designs such as missile seeker electronics and satellite telemetry modules where LM185WG-1.2/883 is commonly deployed.

What is the pin 1 identification method for the LM185WG-1.2/883 CFP package?

Pin 1 of the LM185WG-1.2/883 is identified by a notch or other mark located within the designated area on the package body per NAC0010A outline drawing; alternatively, a tab may be present on lead 1, either side. This marking is visible on the top surface of the ceramic flatpack and aligns with the standard MIL-PRF-38535 orientation convention used across qualified microcircuits-ensuring correct placement during manual or automated assembly of LM185WG-1.2/883 into high-integrity PCBs.

Can the LM185WG-1.2/883 operate from a 1.5 V battery?

Yes, the LM185WG-1.2/883 can operate directly from a 1.5 V alkaline cell, as demonstrated in Figure 17 of its datasheet. With a minimum operating current of 10 µA and forward voltage of −1.0 V to −0.4 V, it functions reliably even as battery voltage drops to 1.3 V. This capability enables LM185WG-1.2/883 to serve as the core reference in ultra-low-power field instruments-such as handheld calibration tools-where battery life must exceed five years without replacement.

Is the LM185WG-1.2/883 pin-compatible with the LM185H-1.2/883?

No, the LM185WG-1.2/883 is not pin-compatible with the LM185H-1.2/883. The LM185WG-1.2/883 uses a 10-pin ceramic flatpack (NAC0010A), whereas the LM185H-1.2/883 uses a 2-pin TO-206AA metal-can package (NDU0002A). Their terminal counts, physical footprints, and thermal interfaces differ fundamentally-requiring distinct PCB layouts and mounting procedures. When migrating between them, LM185WG-1.2/883 offers superior thermal performance and hermetic reliability, but demands redesign of the mechanical interface.