Texas Instruments LM4040C25IDCKT

Overview

LM4040C25IDCKT from Texas Instruments is a precision 2.5V shunt voltage reference in SC-70-5 package, rated for –40°C to 85°C operation, with ±0.5% initial accuracy (25°C), 100 ppm/°C temperature coefficient, 35 μVRMS wideband noise, and stable operation down to 45 μA cathode current. It serves as a compact, low-power reference in analog-to-digital converter biasing and sensor signal conditioning circuits.

For engineers reviewing the LM4040C25IDCKT datasheet, LM4040C25IDCKT pinout, LM4040C25IDCKT application, or LM4040C25IDCKT equivalent, this page delivers verified specifications, validated pin functions, confirmed industrial-temperature performance, and real-world substitution guidance - all aligned to TI's SLOS456Q production data sheet.

Technical Context

The LM4040C25IDCKT operates as a two-terminal shunt reference, sinking cathode current (IZ) to maintain a precise 2.5V reverse breakdown voltage across its terminals. Its Zener-zap trimmed silicon design achieves grade-C accuracy without external components, and it remains stable under all capacitive loads - eliminating need for output capacitance.

It features low dynamic impedance (0.9 Ω typical at 1 mA), thermal hysteresis of 0.08%, and long-term stability of 120 ppm over 1000 hours. The device draws minimal quiescent current (45 μA typical), enabling use in battery-powered instrumentation where power budget and voltage precision are co-constrained.

Key Specifications

Pinout & Package

LM4040C25IDCKT uses the 5-pin SC-70 (DCK) package (2.00 mm × 1.25 mm), optimized for space-constrained PCB layouts. Pin 1 is Anode (ground reference), Pin 3 is Cathode (voltage output node), Pins 4 and 5 are No-Connect (NC), and Pin 2 is the floating or anode-tied terminal for EMI mitigation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM4040C25IDCKT, LM4040C25IDBZR offers identical electrical performance in a mechanically simpler package, while REF3025AIDBZR trades shunt simplicity for lower drift and noise - but demands additional supply margin and passive components.

Availability

LM4040C25IDCKT is available at Aetrix Electronics and suitable for industrial analog input modules, portable data loggers, field transmitters, and energy infrastructure metering requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for LM4040C25IDCKT 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 and embedded processing technologies, with decades of expertise in precision voltage references and industrial-grade signal chain solutions.

The LM4040 series was designed specifically for cost-sensitive, space-constrained applications demanding stable, low-power, two-terminal voltage references - especially in sensor interfaces, programmable logic controllers, and portable instrumentation.

FAQ

What is the operating temperature range for LM4040C25IDCKT?

The LM4040C25IDCKT is characterized for operation from –40°C to +85°C ambient temperature. This industrial-grade range is explicitly defined in TI's SLOS456Q datasheet Section 6.3 and applies to all electrical characteristics in the LM4040C25I variant. It does not support the extended –40°C to +125°C range offered by the Q-suffix variants like LM4040C25Q.

Does LM4040C25IDCKT require an output capacitor?

No, LM4040C25IDCKT is stable with all capacitive loads and requires no output capacitor for operation. This is confirmed in the "Features" section and Section 3 ("Description") of the TI datasheet, which states: "Stable with all capacitive loads; no output capacitor required." Adding one does not harm performance but provides no benefit.

What is the minimum cathode current needed for LM4040C25IDCKT to regulate properly?

The LM4040C25IDCKT requires a minimum cathode current of 45 μA (typical) to maintain regulation. Per Section 6.9 of the datasheet, this value is specified at 25°C and increases to 80 μA across the full –40°C to +85°C range. Below this threshold, the output voltage deviates significantly from 2.5V.

How does the pin configuration of LM4040C25IDCKT differ from the SOT-23 version?

LM4040C25IDCKT uses the 5-pin SC-70 (DCK) package with Pin 1 = Anode, Pin 2 = NC (optional anode tie), Pin 3 = Cathode, and Pins 4–5 = NC. In contrast, the SOT-23 variant (e.g., LM4040C25IDBZR) uses only 3 pins: Pin 1 = Cathode, Pin 2 = Anode, Pin 3 = NC - with no optional EMI pin and different physical orientation.

Can LM4040C25IDCKT be used in place of LM4040A25IDCKT?

Yes, LM4040C25IDCKT can replace LM4040A25IDCKT in applications tolerant of ±0.5% initial accuracy instead of ±0.1%. However, the C-grade part exhibits higher voltage drift (100 ppm/°C vs. 100 ppm/°C same spec, but A-grade has tighter distribution) and wider tolerance bands - so system-level accuracy validation is required before substitution.