Texas Instruments LM4040C50ILPR

Overview

LM4040C50ILPR from Texas Instruments is a precision micropower shunt voltage reference delivering a fixed 5.0 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 voltage基准 in high-resolution ADCs, industrial sensor signal chains, and portable energy infrastructure monitoring systems.

For engineers reviewing the LM4040C50ILPR datasheet, LM4040C50ILPR pinout, LM4040C50ILPR application, or LM4040C50ILPR equivalent, key selection criteria include its guaranteed 5.0 V output tolerance over –40°C to 85°C, minimal 45 μA startup current, no-output-capacitor-required stability, and SOT-23-3 package compatibility with space-constrained PCB layouts.

Technical Context

The LM4040C50ILPR operates as a two-terminal shunt reference, sinking cathode current (I_Z) to maintain a precise 5.0 V reverse breakdown voltage (V_Z) across its terminals. Its Zener-zap trimmed silicon design achieves tight initial tolerance without external components.

It exhibits low dynamic impedance (≤0.9 Ω at 1 mA), thermal hysteresis of 0.08%, and long-term stability of 120 ppm over 1000 hours - enabling consistent performance in analog front-ends where drift directly impacts measurement fidelity.

Key Specifications

Pinout & Package

LM4040C50ILPR is packaged in a 3-pin SOT-23 (DBZ) surface-mount package measuring 2.92 mm × 1.30 mm. The device uses a two-terminal shunt configuration with an 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 REF3050AIDBZR, the LM4040C50ILPR offers the lowest operating current and simplest two-terminal interface, making it optimal for shunt-based, low-voltage, and space-constrained designs - though it trades off some noise and tempco performance.

Availability

LM4040C50ILPR is available at Aetrix Electronics and suitable for data-acquisition systems, energy infrastructure monitoring, and field transmitter designs requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.

Supply support for LM4040C50ILPR 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 connectivity technologies with decades of precision reference design heritage.

The LM4040 family was engineered for cost-sensitive, high-accuracy analog signal conditioning - delivering micropower shunt reference performance in compact packages for industrial, automotive, and portable instrumentation.

FAQ

What is the maximum cathode current rating for LM4040C50ILPR?

The absolute maximum cathode current for LM4040C50ILPR is 25 mA per the datasheet Absolute Maximum Ratings table. However, the recommended operating range is 45 μA to 15 mA. Exceeding 15 mA may increase self-heating and degrade long-term stability; sustained operation above 25 mA risks permanent damage. Always verify power dissipation (P = V_Z × I_Z) remains within thermal limits for the SOT-23 package.

Does LM4040C50ILPR require an output capacitor for stability?

No, LM4040C50ILPR does not require an output capacitor. Its internal design ensures stability with all capacitive loads - including 0 μF - eliminating the need for external bypass capacitors. This simplifies layout, reduces BOM count, and avoids potential resonance issues. TI explicitly states "no output capacitor required" in the Features section and confirms stability across the full operating current range.

What is the operating temperature range specified for LM4040C50ILPR?

LM4040C50ILPR is characterized for operation over the industrial temperature range of –40°C to +85°C. This is confirmed by the "I" suffix in the part number (LM4040C50Ixxx) and verified in Section 4 (Device Comparison Table) and Section 6.3 (Recommended Operating Conditions) of the datasheet. It is not rated for the extended –40°C to +125°C range (Q-grade variants).

How does the NC pin (Pin 3) function in LM4040C50ILPR?

The NC pin (Pin 3) on LM4040C50ILPR has no internal connection and is electrically inactive. TI recommends leaving it floating in standard applications. However, in high-EMI environments - such as near transformers or switching power supplies - connecting Pin 3 to the anode (Pin 2) reduces noise susceptibility. This is a layout-level EMI mitigation technique, not a functional requirement for basic operation.

Can LM4040C50ILPR be used as a replacement for LM4040B50ILPR?

Yes, LM4040C50ILPR can replace LM4040B50ILPR in most applications, but with a trade-off: C grade offers ±0.5% initial accuracy versus B grade's tighter ±0.2%. Both share identical 5.0 V output, 100 ppm/°C tempco, SOT-23 package, and operating range. Use LM4040C50ILPR where cost sensitivity outweighs the need for 0.3% extra accuracy - e.g., non-calibrated industrial sensors - but retain B grade for metrology-grade systems.