Texas Instruments LT1004CD-2-5

Overview

LT1004CD-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 temperature coefficient, and 0.2 Ω typical reference impedance at 100 µA. It operates from 8 µA to 20 mA and serves as a precision reference in portable test instruments, battery-operated systems, and current-loop transmitters.

For engineers reviewing the LT1004CD-2-5 datasheet, LT1004CD-2-5 pinout, LT1004CD-2-5 application, or LT1004CD-2-5 equivalent, this page provides verified specifications, SOIC-8 package details, real-world use cases, and validated alternative options for low-power analog signal conditioning and precision biasing circuits.

Technical Context

The LT1004CD-2-5 implements a monolithic band-gap reference architecture with internal trimming to achieve tight initial tolerance and low thermal drift. Its two-terminal configuration simplifies integration into series-shunt regulator topologies and floating reference designs.

It features ultra-low quiescent current (as low as 8 µA), low dynamic impedance (≤1.5 Ω over full temperature range), and broadband noise of 60–120 µV RMS (10 Hz–10 kHz), enabling stable operation in high-resolution ADCs and low-noise instrumentation amplifiers without external buffering.

Key Specifications

Pinout & Package

LT1004CD-2-5 is housed in an 8-pin SOIC (D) package with 1.27 mm lead pitch and 1.75 mm max height. Pins 6 and 8 are internally connected cathodes; pins 1, 2, 3, and 7 are no-connect terminals. Only pins 4 (anode) and 5 (cathode) are functional.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM385BD-2-5, LT1004CD-2-5 delivers tighter initial accuracy and lower thermal drift at micropower levels; versus REF192GS, it trades absolute precision for ultra-low current consumption and two-terminal simplicity in space-constrained loops.

Availability

LT1004CD-2-5 is available at Aetrix Electronics and suitable for portable test instrumentation, battery-operated data loggers, and 4–20 mA loop transmitters requiring stable component supply with guaranteed long-term continuity.

Supply support for LT1004CD-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 since 1930.

The LT1004 series was designed specifically for micropower, two-terminal voltage referencing in portable and battery-critical systems-prioritizing low operating current, minimal board area, and robust performance across commercial temperature ranges.

FAQ

What is the maximum reverse current rating for LT1004CD-2-5?

The absolute maximum reverse current for LT1004CD-2-5 is 30 mA, as specified in the TI SLVS022M datasheet. Exceeding this value risks permanent damage. In normal operation, the device functions as a two-terminal shunt reference, sinking current through its cathode (pin 5) while maintaining 2.5 V across anode (pin 4) and cathode. The LT1004CD-2-5 must be biased with a current-limiting resistor to ensure operation within 8 µA–20 mA for stable regulation.

Can LT1004CD-2-5 replace LM385-2.5 in existing designs?

Yes, LT1004CD-2-5 is explicitly documented as a pin-for-pin replacement for the LM385 series with improved specifications. Both use SOIC-8 packages and share identical pin 4 (anode) and pin 5 (cathode) functionality. The LT1004CD-2-5 offers tighter initial accuracy (±20 mV vs ±30 mV), lower temperature coefficient (20 ppm/°C vs 50 ppm/°C), and lower reference impedance (0.2 Ω vs 2 Ω). No PCB changes are required, though layout review is recommended to confirm thermal relief on pins 6/8.

What is the minimum operating current to maintain regulation for LT1004CD-2-5?

The maximum minimum reference current (IZ(min)) for LT1004CD-2-5 is 12 µA across its full operating temperature range (0°C to 70°C). Below this threshold, regulation degrades and output voltage deviates from 2.5 V. At 25°C, regulation is maintained down to 8 µA. Designers must size the series current-limiting resistor to ensure ≥12 µA flows through the LT1004CD-2-5 under worst-case low-temperature, low-input-voltage conditions.

Does LT1004CD-2-5 require external capacitors for stability?

No, LT1004CD-2-5 is inherently stable and does not require external output capacitors for basic regulation. Its two-terminal architecture and internal compensation eliminate phase-margin concerns seen in three-terminal references. However, a 100 pF capacitor placed directly at the cathode (pin 5) is recommended in noisy environments to suppress RF pickup, and a 0.1 µF ceramic capacitor improves transient response in fast-switching applications like DAC reference buffers.

What is the long-term stability of LT1004CD-2-5 over time?

The LT1004CD-2-5 exhibits a long-term change in reference voltage of 20 ppm per kilohour (ppm/khr) when operated at 100 µA and 25°C, as measured per TI's characterization. This equates to approximately 175 ppm/year (≈0.44 mV drift at 2.5 V) under continuous operation. For mission-critical applications requiring sub-100 ppm/year stability, periodic recalibration or selection of a laser-trimmed reference like REF5025 is advised.