Texas Instruments LM4040C41ILP

Overview

LM4040C41ILP from Texas Instruments is a precision micropower shunt voltage reference with 4.096V nominal 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 analog-to-digital converters and sensor signal conditioning circuits.

For engineers reviewing the LM4040C41ILP datasheet, LM4040C41ILP pinout, LM4040C41ILP application, or LM4040C41ILP equivalent, this page delivers verified electrical specs, package mapping to SOT-23-3 (LP), thermal performance data, and validated alternative parts for industrial-grade precision voltage referencing.

Technical Context

The LM4040C41ILP operates as a two-terminal shunt reference, sinking cathode current (IZ) to maintain a stable 4.096V reverse breakdown voltage across its cathode-anode terminals. Its Zener-zap trimmed bandgap architecture achieves tight initial tolerance and low thermal drift without external capacitors.

It features low dynamic impedance (0.3–0.9Ω at 1mA), supports all capacitive loads, and is characterized over –40°C to +85°C ambient temperature. The device uses fuse-based wafer-level trimming to achieve C-grade 0.5% accuracy and maintains long-term stability of 120ppm after 1000 hours.

Key Specifications

Pinout & Package

LM4040C41ILP is packaged in a 3-pin TO-92 (LP) through-hole package measuring 4.83mm × 3.68mm. Pin 1 is Cathode, Pin 2 is Anode (ground), Pin 3 is NC (No Internal Connection), though TI recommends leaving Pin 3 floating or connecting it to the anode in high-EMI environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM4040C41ILP, LM4040C41IDBZR offers identical performance in a smaller SMT package but demands PCB redesign, while REF3040AIDBZR improves accuracy and drift at the cost of topology flexibility and supply dependency.

Availability

LM4040C41ILP is available at Aetrix Electronics and suitable for energy infrastructure metering, industrial analog input modules, field transmitter calibration, and portable data-acquisition systems requiring stable component supply with guaranteed long-term availability.

Supply support for LM4040C41ILP 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 technologies, with decades of heritage in precision reference design.

The LM4040 family was engineered for cost-sensitive, high-reliability industrial and instrumentation applications demanding micropower operation, robust thermal performance, and production-ready accuracy without calibration.

FAQ

What is the output voltage tolerance of LM4040C41ILP at room temperature?

The LM4040C41ILP has a maximum initial output voltage tolerance of ±0.5% at 25°C, corresponding to ±20.5mV around the 4.096V nominal value. This specification is guaranteed per TI's C-grade characterization and applies under IZ = 100μA test condition.

Can LM4040C41ILP operate with zero external capacitance?

Yes, LM4040C41ILP is inherently stable with all capacitive loads and requires no output capacitor for proper operation. Its design eliminates the need for external bypassing, simplifying layout and reducing bill-of-materials cost in space-constrained designs.

What is the minimum cathode current needed for LM4040C41ILP to regulate properly?

The LM4040C41ILP requires a minimum cathode current of 45μA (typical) at 25°C to maintain regulation. Over the full –40°C to +85°C range, the guaranteed minimum is 80μA - critical for low-power sensor biasing and battery-backed applications.

How does the thermal hysteresis of LM4040C41ILP affect system calibration?

LM4040C41ILP exhibits 0.08% thermal hysteresis, meaning its output voltage may differ by up to ±3.3mV at 25°C depending on prior thermal history (e.g., cycling to –40°C vs. +125°C). This must be accounted for in high-accuracy calibration routines requiring repeatability after environmental stress.

Is LM4040C41ILP compatible with lead-free soldering processes?

Yes, LM4040C41ILP in TO-92 (LP) package is rated for standard lead-free reflow profiles per JEDEC J-STD-020. Its package construction supports peak temperatures up to 260°C for 10 seconds, making it suitable for modern RoHS-compliant manufacturing lines.