Texas Instruments LM4040D50ILPR

Overview

LM4040D50ILPR from Texas Instruments is a precision micropower shunt voltage reference delivering a fixed 5.0 V output with ±1.0% initial accuracy (D grade), 150 ppm/°C temperature coefficient, 35 μV_RMS wideband noise, and stable operation from 45 μA to 15 mA cathode current - used in high-accuracy analog input modules and field transmitters requiring low-drift, low-noise biasing.

For engineers reviewing the LM4040D50ILPR datasheet, LM4040D50ILPR pinout, LM4040D50ILPR application, or LM4040D50ILPR equivalent, key selection criteria include industrial temperature range (–40°C to +85°C), SOT-23-3 package compatibility, no-output-capacitor operation, and tight tolerance under varying load and thermal conditions.

Technical Context

The LM4040D50ILPR operates as a two-terminal shunt reference: cathode accepts input current while anode connects to system ground, establishing a precise 5.0 V reverse breakdown voltage across its terminals. Its Zener-zap trimmed silicon design ensures stable regulation without external capacitors, even with heavy capacitive loads.

It features low dynamic impedance (≤1.1 Ω at 1 mA), minimal thermal hysteresis (0.08%), and long-term stability of 120 ppm over 1000 hours - enabling reliable performance in portable instrumentation and energy infrastructure monitoring where supply headroom is constrained and thermal cycling occurs.

Key Specifications

Pinout & Package

LM4040D50ILPR is packaged in a 3-pin SOT-23 (DBZ) surface-mount package measuring 2.92 mm × 1.30 mm. The device has no power supply pins - it functions as a two-terminal shunt element with optional third 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 TL4050C50IDBZR and MAX6005EUR+T, the LM4040D50ILPR offers the lowest cost-per-unit for industrial-grade 5 V referencing with proven SOT-23 reliability, while trading off some accuracy and noise performance for broader design flexibility and EMI mitigation capability via Pin 3.

Availability

LM4040D50ILPR is available at Aetrix Electronics and suitable for analog input modules, field transmitters, and data-acquisition systems requiring stable component supply, consistent parametric performance, and long-term manufacturing continuity.

Supply support for LM4040D50ILPR 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 expertise in precision reference design.

The LM4040 series was engineered for cost-sensitive, space-constrained industrial and portable applications demanding micropower operation, capacitor-free stability, and guaranteed performance across extended temperature ranges.

FAQ

What is the maximum cathode current rating for LM4040D50ILPR?

The LM4040D50ILPR has an absolute maximum cathode current of 25 mA per its Absolute Maximum Ratings table. However, the recommended operating range is 45 μA to 15 mA. Exceeding 15 mA risks exceeding the device's power dissipation limit in SOT-23 packaging, especially at elevated ambient temperatures - sustained operation above this level may degrade long-term stability or cause thermal shutdown in adjacent circuitry.

Does LM4040D50ILPR require an output capacitor for stability?

No, the LM4040D50ILPR is explicitly designed to be stable with all capacitive loads and does not require an output capacitor. This is confirmed in both the Features list and Description section of the datasheet. Adding capacitance at the cathode improves noise rejection but is optional - unlike many bandgap references, the LM4040D50ILPR's Zener-based architecture inherently avoids phase-margin issues that necessitate external compensation.

Can LM4040D50ILPR be used in automotive applications?

The LM4040D50ILPR is specified for –40°C to +85°C (industrial grade), not the full automotive AEC-Q100 temperature range (–40°C to +125°C). While it may function in under-hood environments, Texas Instruments does not qualify or guarantee its performance beyond +85°C ambient. For automotive use, consider the LM4040D50Q variant (Q-grade, –40°C to +125°C) or automotive-qualified alternatives like MAX6005EUR+T.

What is the purpose of Pin 3 (NC) on LM4040D50ILPR?

Pin 3 on the LM4040D50ILPR is a no-connect terminal with no internal bond wire. Per the datasheet, it should remain floating in standard applications. However, TI recommends connecting Pin 3 to the anode (Pin 2) in high-EMI environments - such as near transformers or DC-DC converters - to reduce noise coupling into the reference node and improve PSRR at high frequencies.

How does the 150 ppm/°C temperature coefficient affect accuracy over temperature for LM4040D50ILPR?

With a 5.0 V nominal output and 150 ppm/°C max tempco, the LM4040D50ILPR contributes up to ±0.975% error over its full –40°C to +85°C range (ΔT = 125°C). Combined with its ±1.0% initial tolerance, total worst-case error is ±1.975% - verified in the datasheet's overtemperature tolerance calculation for D-grade devices. This is acceptable for industrial sensor interfaces but insufficient for metrology-grade systems requiring <±0.1% total error.