Texas Instruments LM4040C25ILPR

Overview

LM4040C25ILPR from Texas Instruments is a precision micropower shunt voltage reference delivering a fixed 2.5 V output with ±0.5% initial accuracy (C grade), 100 ppm/°C temperature coefficient, 35 μV_RMS wideband noise, and stable operation from 45 μA to 15 mA cathode current. It serves as a low-drift, low-noise reference in high-resolution ADCs, sensor signal conditioning, and industrial analog input modules.

For engineers reviewing the LM4040C25ILPR datasheet, LM4040C25ILPR pinout, LM4040C25ILPR application, or LM4040C25ILPR equivalent, key selection criteria include its guaranteed 2.5 V output tolerance over –40°C to +85°C, no-output-capacitor-required stability, SC-70 package footprint, and compatibility with high-impedance bias networks in portable and space-constrained systems.

Technical Context

The LM4040C25ILPR operates as a two-terminal shunt reference, sinking cathode current (I_Z) to maintain a precise 2.5 V reverse breakdown voltage across its terminals. Its Zener-zap trimmed bandgap core ensures tight initial tolerance and low thermal drift without external components.

It achieves stable regulation across capacitive loads up to 10 nF and supports wide operating current (45 μA–15 mA) while maintaining low dynamic impedance (<0.9 Ω at 1 mA) and low long-term drift (120 ppm after 1000 h). The device is characterized for industrial temperature range (–40°C to +85°C) and qualified per TI's standard reliability testing.

Key Specifications

Pinout & Package

LM4040C25ILPR is packaged in a 5-pin SC-70 (DCK) package measuring 2.00 mm × 1.25 mm. Pin 1 = Anode (ground reference), Pin 2 = Cathode (output/reference node), Pins 4–5 = No Internal Connection (NC).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL4050C25IDBZR, LM4040C25ILPR offers superior temperature stability (100 vs. 50 ppm/°C max) at the cost of slightly higher noise; compared with REF3025AIDBZR, it provides true shunt operation with zero input headroom requirement but trades 0.3% tighter initial accuracy for simpler biasing and smaller footprint.

Availability

LM4040C25ILPR is available at Aetrix Electronics and suitable for industrial analog input modules, field transmitters, and portable data-acquisition systems requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.

Supply support for LM4040C25ILPR 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 power management ICs with decades of precision reference design heritage.

The LM4040 family was engineered for cost-sensitive, space-constrained applications demanding high accuracy, low power, and robustness-especially in industrial sensing, test equipment, and portable instrumentation.

FAQ

What is the maximum cathode current rating for LM4040C25ILPR?

The absolute maximum cathode current for LM4040C25ILPR is 25 mA, but the recommended operating range is 45 μA to 15 mA. Exceeding 15 mA may increase self-heating and degrade long-term stability; operation above 25 mA risks permanent damage per TI's Absolute Maximum Ratings table.

Does LM4040C25ILPR require an output capacitor for stability?

No, LM4040C25ILPR is inherently stable with all capacitive loads and does not require an output capacitor. Its design eliminates the need for external stabilization components, reducing BOM count and PCB area-critical for compact sensor nodes and modular analog input designs.

What is the thermal hysteresis specification for LM4040C25ILPR?

LM4040C25ILPR exhibits 0.08% thermal hysteresis, defined as the voltage difference measured at 25°C after cycling to –40°C versus after cycling to +125°C. This low hysteresis ensures repeatable reference performance during thermal cycling in field-deployed industrial equipment.

Can LM4040C25ILPR be used in automotive applications?

LM4040C25ILPR is rated for –40°C to +85°C (industrial grade), not the extended –40°C to +125°C required for most automotive under-hood applications. For automotive use, TI's LM4040C25Q (Q-grade) variant is specified and qualified-LM4040C25ILPR itself is not AEC-Q200 qualified.

How does the 100 ppm/°C temperature coefficient impact LM4040C25ILPR output over temperature?

With a 100 ppm/°C max temperature coefficient, LM4040C25ILPR contributes ≤±6.5 mV drift over its full –40°C to +85°C operating range (ΔT = 125°C), calculated as 2.5 V × 100 ppm/°C × 125°C = ±31.25 mV worst-case-but datasheet overtemperature tolerance for C grade is ±1.15%, or ±28.75 mV, which bounds actual deviation.