Texas Instruments LT1009ID

Overview

LT1009ID from Texas Instruments is a precision 2.5-V shunt voltage reference IC in SOIC-8 package, rated for –40°C to +85°C operation, with ±10 mV initial tolerance (±0.4%), 20 ppm/°C max average temperature coefficient, 0.6 Ω max dynamic impedance at 1 mA, and adjustable ±5% output via ADJ pin. It serves as a stable reference in 5-V system monitoring, 8-bit ADC/DAC circuits, and industrial power-supply feedback loops.

For engineers reviewing the LT1009ID datasheet, LT1009ID pinout, LT1009ID application, or LT1009ID equivalent, this page delivers verified electrical specs, thermal limits, adjustment behavior, package dimensions, and real-world use cases - all confirmed for the LT1009ID variant with industrial temperature grade and SOIC-D packaging.

Technical Context

The LT1009ID operates as a two-terminal shunt reference with a third ADJ terminal enabling ±5% output voltage trimming without degrading temperature coefficient. Its internal architecture uses on-chip laser trimming to achieve tight initial tolerance and low αVZ, eliminating external trim networks required by legacy references like LM136.

It functions across 400 µA–10 mA cathode current, maintains stable 2.5 V output under varying load and temperature, and exhibits 1.4 Ω full-range dynamic impedance. The device draws no quiescent current when unpowered and supports reverse-voltage protection up to 20 mA.

Key Specifications

Pinout & Package

LT1009ID is housed in an 8-pin SOIC (D) package per JEDEC MS-012, with 1.75 mm max height, 3.9 mm body width, and 1.27 mm lead pitch. Pin 1 is located at top-left corner with notch marking; pins 1–4 on top row, 5–8 on bottom row (left-to-right).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM136-2.5, LT1009ID delivers 5× lower temperature coefficient and eliminates trim hardware; versus TL431ACDR, it offers 2.5× better initial accuracy and 2.5× lower drift - making LT1009ID optimal for high-stability 8-bit measurement and control systems.

Availability

LT1009ID is available at Aetrix Electronics and suitable for industrial power-supply monitors, 8-bit data acquisition systems, and 5-V embedded reference applications requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for LT1009ID 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 delivering analog, embedded processing, and logic solutions with emphasis on reliability, precision, and industrial-grade qualification.

The LT1009 series was designed specifically for high-accuracy voltage referencing in measurement, control, and power-conversion systems where long-term stability and minimal thermal drift are critical.

FAQ

What is the maximum operating junction temperature for LT1009ID?

The LT1009ID has a maximum operating virtual junction temperature of 150°C. This limit is defined in the Absolute Maximum Ratings table and applies across its full industrial temperature range (–40°C to +85°C ambient). Thermal design must ensure that power dissipation - calculated as (TJ(max) – TA)/θJA - stays within safe margins, especially given its 97°C/W junction-to-ambient thermal resistance in SOIC-D package.

Can LT1009ID replace LM136-2.5 without circuit modifications?

Yes, LT1009ID is explicitly specified as directly interchangeable with LM136-2.5 in the datasheet. Both share identical pinout (SOIC-8), same cathode/anode/adjust functionality, and compatible voltage/current characteristics. No PCB changes or schematic updates are needed - the LT1009ID simply removes the need for external trim components while improving accuracy and thermal stability.

What is the purpose of the NC pins on LT1009ID?

The LT1009ID has four no-connect (NC) pins: pins 1, 2, 3, and 6. These pins have no internal silicon connection and serve only mechanical or package-integrity roles. They must be left unconnected - neither tied to ground nor routed - to avoid unintended coupling or parasitic effects. Their presence accommodates shared SOIC-8 footprint across TI's reference portfolio.

How does the ADJ pin affect LT1009ID's temperature coefficient?

The ADJ pin on LT1009ID enables ±5% output adjustment without altering the temperature coefficient. As stated in the datasheet, "This does not affect temperature coefficient." The internal trimming ensures αVZ remains ≤20 ppm/°C across the full adjustment range, preserving stability in calibrated systems where fine-tuning compensates for board-level errors without sacrificing thermal performance.

Is LT1009ID RoHS compliant and lead-free?

Yes, LT1009ID is RoHS compliant and features NiPdAu (NIPDAU) lead finish, as confirmed in TI's Package Option Addendum. It meets JEDEC J-STD-020 moisture sensitivity Level-1 (unlimited floor life at ≤30°C/60% RH) and is qualified for lead-free reflow per IPC/JEDEC J-STD-020, with peak reflow temperature of 260°C.