Texas Instruments LM4040D25ILPR

Overview

LM4040D25ILPR from Texas Instruments is a precision micropower shunt voltage reference with a fixed 2.5V output, D-grade (±1.0% initial tolerance, 150ppm/°C tempco), rated for –40°C to 85°C operation, 45μA minimum cathode current, and 35μVRMS wideband noise - used in analog input modules and field transmitters requiring stable low-power biasing.

For engineers reviewing the LM4040D25ILPR datasheet, LM4040D25ILPR pinout, LM4040D25ILPR application, or LM4040D25ILPR equivalent, key selection criteria include initial accuracy vs. temperature coefficient trade-offs, cathode current range compatibility with series resistor design, stability under capacitive loads, and SOT-23-3 package thermal performance in space-constrained industrial PCBs.

Technical Context

The LM4040D25ILPR operates as a two-terminal shunt reference, sinking cathode current (IZ) to regulate voltage across its terminals without requiring an output capacitor. Its Zener-zap trimmed reverse breakdown voltage ensures fixed 2.5V output with guaranteed tolerance over temperature.

It delivers low dynamic impedance (≤1.1Ω at 1mA), low noise (35μVRMS, 10Hz–10kHz), and stable regulation across 45μA–15mA cathode current - enabling use in high-resolution ADC biasing, sensor excitation, and portable instrumentation where supply headroom is limited.

Key Specifications

Pinout & Package

LM4040D25ILPR is packaged in a 3-pin SOT-23 (DBZ) surface-mount package measuring 2.92mm × 1.30mm. The device uses a two-terminal shunt configuration with a third no-connect pin for mechanical robustness and thermal relief.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL4050C25IDBZR and MAX6008AEUR+T, the LM4040D25ILPR trades initial accuracy and noise performance for lower cost, wider cathode current range, and proven reliability in harsh industrial environments - making it optimal for cost-sensitive, thermally variable applications where ±1% system-level tolerance is acceptable.

Availability

LM4040D25ILPR is available at Aetrix Electronics and suitable for industrial analog input modules, field transmitters, energy infrastructure monitoring, and precision audio level detection requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for LM4040D25ILPR 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 reference design and high-volume manufacturing.

The LM4040 series was developed for cost-effective, space-efficient shunt reference needs in industrial, automotive, and instrumentation systems - emphasizing micropower operation, wide current range, and robust thermal performance without external components.

FAQ

What is the maximum cathode current rating for LM4040D25ILPR?

The absolute maximum cathode current for LM4040D25ILPR is 25mA, per TI's Absolute Maximum Ratings table. However, the recommended operating range is 45μA to 15mA - exceeding 15mA risks thermal overload in the SOT-23 package unless board-level heatsinking is implemented. Continuous operation above 15mA should be validated with junction temperature calculations using RθJA = 206°C/W.

Does LM4040D25ILPR require an output capacitor for stability?

No, LM4040D25ILPR does not require an output capacitor. Its internal design ensures stability with all capacitive loads, including direct connection to ADC reference inputs or op-amp bias nodes. This eliminates capacitor-related drift, aging, and PCB area - a key advantage over series references in space-constrained layouts.

How does the D-grade tolerance of LM4040D25ILPR impact system-level accuracy?

The D-grade ±1.0% initial tolerance of LM4040D25ILPR contributes directly to full-scale error in ADC-based systems. Combined with its 150ppm/°C tempco, total error over –40°C to 85°C is ≤±1.98%, or ±49.5mV at 2.5V. System calibration can correct initial offset, but tempco-induced drift remains - making it suitable for applications where end-of-line calibration is performed.

Can LM4040D25ILPR be used in automotive applications?

LM4040D25ILPR is qualified for –40°C to 85°C operation (industrial grade), not the full AEC-Q100 automotive temperature range (–40°C to 125°C). For under-hood or infotainment systems requiring 125°C operation, TI's LM4040D25Q variant (with Q suffix) is specified - the ILPR suffix confirms industrial temperature screening only.

What is the purpose of Pin 3 (NC) on LM4040D25ILPR?

Pin 3 on LM4040D25ILPR is a no-connect terminal with no internal bond wire. It serves mechanical and thermal functions - improving solder joint reliability and aiding heat dissipation in the SOT-23 package. TI recommends leaving it floating or connecting it to the anode (Pin 2) in high-EMI environments, but it must never be driven or loaded externally.