Texas Instruments LM4040C41ILPR

Overview

LM4040C41ILPR from Texas Instruments is a precision micropower shunt voltage reference with a fixed 4.096V output, ±0.5% initial accuracy (C grade), 100ppm/°C temperature coefficient, 35μVRMS wideband noise, and stable operation from 45μA to 15mA cathode current. It serves as a compact, low-drift reference in high-resolution ADCs and sensor signal chains for industrial process control.

For engineers reviewing the LM4040C41ILPR datasheet, LM4040C41ILPR pinout, LM4040C41ILPR application, or LM4040C41ILPR equivalent, key selection criteria include its 4.096V output matching common 12-bit DAC/ADC full-scale ranges, C-grade accuracy–cost balance, SOT-23-3 package compatibility with space-constrained PCB layouts, and guaranteed operation from –40°C to +85°C.

Technical Context

The LM4040C41ILPR operates as a two-terminal shunt reference, sinking cathode current (IZ) to maintain a precise 4.096V reverse breakdown voltage across its terminals. Its Zener-zap trimmed silicon design achieves ±0.5% initial tolerance at 25°C and maintains stability over –40°C to +85°C via a 100ppm/°C tempco.

It requires no external capacitor, exhibits low dynamic impedance (≤0.9Ω at 1mA), and delivers low-noise performance (35μVRMS, 10Hz–10kHz) - enabling direct use in precision analog front-ends without post-regulation filtering.

Key Specifications

Pinout & Package

LM4040C41ILPR is packaged in a 3-pin SOT-23 (DBZ) case measuring 2.92mm × 1.30mm, optimized for high-density PCB layouts and reflow assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM4040C41IDBVR, the LM4040C41ILPR shares identical electrical behavior but differs only in packaging format - making it a direct form-fit replacement for hand-soldered or low-volume builds. Against REF3040AIDBVR, the LM4040C41ILPR trades 0.3% initial accuracy and 10ppm/°C tempco for 5μA lower minimum current and ~30% lower unit cost in volume production.

Availability

LM4040C41ILPR is available at Aetrix Electronics and suitable for industrial analog input modules, energy infrastructure metering, and field transmitter signal conditioning requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for LM4040C41ILPR 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and personal electronics markets.

The LM4040 series was designed specifically for precision shunt reference applications demanding low drift, micropower operation, and robustness across industrial temperature ranges - targeting data acquisition, sensor conditioning, and closed-loop control systems.

FAQ

What is the exact output voltage tolerance of the LM4040C41ILPR at 25°C?

The LM4040C41ILPR has a ±0.5% initial output voltage tolerance at 25°C, corresponding to ±20.48mV around the nominal 4.096V output. This is specified in the C-grade electrical characteristics table (Section 6.15 of the TI datasheet) and confirmed by TI's wafer-sort trimming process.

Does the LM4040C41ILPR require an external output capacitor?

No, the LM4040C41ILPR does not require an external output capacitor. Its internal design ensures stability with all capacitive loads, including direct connection to ADC reference inputs or op-amp feedback networks - a key advantage over many series references that mandate minimum capacitance for phase margin.

What is the minimum cathode current needed for regulation in the LM4040C41ILPR?

The LM4040C41ILPR requires a minimum cathode current of 45μA (typical) to maintain regulation. At temperatures up to +85°C, this increases to 80μA (max), as specified in Section 6.15 of the TI datasheet. Below this threshold, the output voltage deviates significantly from 4.096V.

Which package type is used by the LM4040C41ILPR?

The LM4040C41ILPR uses the SOT-23-3 (DBZ) package - a 3-pin surface-mount outline measuring 2.92mm × 1.30mm. Pin 1 is Cathode, Pin 2 is Anode, and Pin 3 is NC (no internal connection), per TI's Pin Configuration and Functions diagram (Figure 5-1).

Can the LM4040C41ILPR operate reliably at 125°C ambient temperature?

No, the LM4040C41ILPR is rated for operation from –40°C to +85°C only. For extended temperature operation up to +125°C, TI offers the LM4040C41Q variant (e.g., LM4040C41QDBZR); the 'I' suffix in LM4040C41ILPR explicitly denotes the industrial temperature grade.