Texas Instruments LT1004IDRE4-2-5

Overview

LT1004IDRE4-2-5 from Texas Instruments is a two-terminal micropower band-gap voltage reference IC delivering 2.5 V nominal output with ±20 mV initial accuracy, 20 ppm/°C average temperature coefficient, and 0.2–0.6 Ω reference impedance at 100 µA-designed for precision low-power systems including portable test instruments and battery-operated current-loop transmitters.

For engineers reviewing the LT1004IDRE4-2-5 datasheet, LT1004IDRE4-2-5 pinout, LT1004IDRE4-2-5 application, or LT1004IDRE4-2-5 equivalent, this page provides verified specifications, SOIC-8 package terminal mapping, real-world use cases in cold-junction compensation and micropower 5-V regulation, and validated alternative parts for industrial-grade voltage reference selection.

Technical Context

The LT1004IDRE4-2-5 operates as a two-terminal shunt reference requiring only an external current-limiting resistor to establish its bias point. Its internal band-gap core delivers stable 2.5 V output across −40°C to +85°C, with low 60–120 µV broadband noise (10 Hz–10 kHz) and minimal 10 mV voltage change over 1–20 mA operating current range.

It replaces LM285/LM385 series references with improved initial accuracy and temperature stability while maintaining identical pinout and functional compatibility. The device draws as little as 8 µA minimum reference current and supports up to 20 mA maximum reverse current without degradation.

Key Specifications

Pinout & Package

LT1004IDRE4-2-5 is housed in an 8-pin SOIC (D package), 3.91 mm × 4.90 mm body, 1.75 mm max height, RoHS-compliant with NiPdAu lead finish. Pins 6 and 8 are internally connected cathodes; pins 1, 3, 4, 6, 7, and 8 are no-connect (NC) except for cathode bonding. Only pins 2 (Anode) and 5 (Cathode) are functional terminals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM385BIMX-2.5, LT1004IDRE4-2-5 offers tighter accuracy and industrial temperature support; compared with REF3025AIDBZR, it retains two-terminal simplicity and ultra-low current operation but trades off initial tolerance for ease of integration in space-constrained shunt topologies.

Availability

LT1004IDRE4-2-5 is available at Aetrix Electronics and suitable for portable meter reference, battery-operated systems, and current-loop instrumentation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LT1004IDRE4-2-5 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 company headquartered in Dallas, Texas, specializing in analog and embedded processing technologies with over 90 years of innovation in precision analog ICs.

The LT1004 series was designed as a micropower shunt reference family targeting portable, battery-sensitive, and industrial-grade instrumentation where low power, small size, and stable voltage references are essential.

FAQ

What is the operating temperature range for the LT1004IDRE4-2-5?

The LT1004IDRE4-2-5 is characterized for operation from −40°C to +85°C, meeting industrial-grade environmental requirements. This range is confirmed in the ordering information table and electrical characteristics section of the SLVS022M datasheet, where all "Full range" parameters for the LT1004I grade are explicitly defined across this span. The device maintains its 2.47–2.53 V reference voltage and 20 ppm/°C temperature coefficient within this interval.

Is LT1004IDRE4-2-5 pin-compatible with LM385-2.5?

Yes, LT1004IDRE4-2-5 is a pin-for-pin replacement for LM385-2.5 and LM285-2.5, as stated in the datasheet's description section. Both devices use identical SOIC-8 packaging with Anode on Pin 2 and Cathode on Pin 5, and share the same NC pin configuration. No PCB layout changes are required when upgrading, though improved initial accuracy (±20 mV vs ±30 mV) and lower temperature coefficient (20 ppm/°C vs 50 ppm/°C) provide immediate performance gains.

What is the minimum current required for LT1004IDRE4-2-5 to regulate properly?

The LT1004IDRE4-2-5 requires a minimum reference current of 8–12 µA across its operating temperature range, as specified in the "IZ(min)" row of the electrical characteristics table. Below this threshold, the device exits regulation and output voltage collapses. Designers must size the series current-setting resistor to ensure ≥12 µA at the lowest expected supply voltage and highest junction temperature to guarantee stable 2.5 V output.

Can LT1004IDRE4-2-5 be used in a 3.3 V system?

Yes, LT1004IDRE4-2-5 can operate in a 3.3 V system when configured as a shunt reference with appropriate current limiting. With a 3.3 V supply and 2.5 V reference, the series resistor must drop 0.8 V. For example, at 100 µA bias, a 8 kΩ resistor achieves regulation. The device's 8–12 µA minimum current ensures reliable startup even at reduced headroom, and its low 0.2 Ω impedance prevents significant voltage droop under light loading.

Does LT1004IDRE4-2-5 require an output capacitor for stability?

Yes, the datasheet recommends a minimum 100 pF capacitor from Cathode (Pin 5) to Anode (Pin 2) to ensure stability, especially under dynamic load conditions. Figure 15 (Transient Response) shows clean step response only with proper capacitive bypassing. Larger values (e.g., 1 nF) further reduce noise but increase turn-on time; 100 pF strikes optimal balance between stability, noise suppression, and speed for most micropower applications using LT1004IDRE4-2-5.