Texas Instruments LM4040B41IDCKR

Overview

LM4040B41IDCKR from Texas Instruments is a precision micropower shunt voltage reference with 4.096 V nominal output, ±0.2% initial accuracy (B 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 compact, low-drift reference in high-resolution ADC/DAC biasing and sensor signal conditioning circuits.

For engineers reviewing the LM4040B41IDCKR datasheet, LM4040B41IDCKR pinout, LM4040B41IDCKR application, or LM4040B41IDCKR equivalent, key selection criteria include output tolerance over –40°C to 85°C, dynamic impedance below 0.9 Ω at 1 mA, thermal hysteresis of 0.08%, long-term stability of 120 ppm, and SC-70 package compatibility with space-constrained PCB layouts.

Technical Context

The LM4040B41IDCKR operates as a two-terminal shunt reference, sinking cathode current to maintain a precise 4.096 V reverse breakdown voltage across its terminals. Its Zener-zap trimmed silicon design delivers tight initial tolerance and low drift without requiring external capacitors or series resistors for basic operation.

It features low dynamic impedance (≤0.9 Ω), minimal voltage variation with cathode current (≤6 mV over 1–15 mA), and robust stability with all capacitive loads - enabling direct integration into analog front-ends where supply headroom is limited and load capacitance varies.

Key Specifications

Pinout & Package

LM4040B41IDCKR is packaged in a 5-pin SC-70 (DCK) package measuring 2.00 mm × 1.25 mm. Pin 1 is Anode (ground reference), Pin 3 is Cathode (output/reference node), Pins 4 and 5 are No Connect (NC). Pin 2 is the "*" terminal, which must float or be tied to the anode to suppress EMI in noisy environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM4040C41IDCKR, the LM4040B41IDCKR provides tighter initial tolerance for improved absolute accuracy in calibration-critical roles; compared with REF3040AIDBZR, it offers simpler two-terminal operation and lower minimum operating current but lacks series regulator advantages like load regulation and reverse-polarity protection.

Availability

LM4040B41IDCKR is available at Aetrix Electronics and suitable for data-acquisition systems, energy infrastructure monitoring, and field transmitter designs requiring stable component supply with guaranteed long-term availability and traceable lot-level documentation.

Supply support for LM4040B41IDCKR 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 expertise in precision analog ICs.

The LM4040 series was designed specifically for high-accuracy, low-power shunt reference applications in portable instrumentation, industrial sensing, and automotive subsystems where space, power, and stability are critical.

FAQ

What is the operating temperature range for LM4040B41IDCKR?

The LM4040B41IDCKR is characterized for operation from –40°C to +85°C (industrial temperature range). Its electrical specifications - including initial accuracy, temperature coefficient, and dynamic impedance - are guaranteed across this full range, making it suitable for deployment in outdoor metering and factory automation equipment without derating.

Does LM4040B41IDCKR require an external output capacitor?

No, LM4040B41IDCKR is stable with all capacitive loads and does not require an external output capacitor. This eliminates a common BOM item and layout constraint, especially beneficial in space-limited applications like handheld test gear and modular sensor nodes where board real estate is at a premium.

How does the * pin (Pin 2) function on LM4040B41IDCKR?

The * pin (Pin 2) on LM4040B41IDCKR is an EMI suppression terminal. It must either float or be connected directly to the anode (Pin 1). TI recommends tying it to the anode only in high-noise environments - such as near switching power supplies or motor drives - to reduce sensitivity to electromagnetic interference without affecting normal regulation performance.

What is the minimum cathode current needed for LM4040B41IDCKR to regulate properly?

The LM4040B41IDCKR requires a minimum cathode current of 45 μA (typical) to maintain regulation. At 25°C, regulation is guaranteed down to 75 μA; over the full –40°C to +85°C range, the guaranteed minimum is 80 μA. This ultra-low requirement supports use with high-value bias resistors or micro-power microcontrollers.

Can LM4040B41IDCKR replace LM4040A41IDCKR in a design?

Yes, LM4040B41IDCKR can replace LM4040A41IDCKR in most designs, though with relaxed initial accuracy: LM4040A41IDCKR offers ±0.1%, while LM4040B41IDCKR offers ±0.2%. Both share identical pinout, package, temperature coefficient, noise, and operating current range - so no PCB or schematic changes are needed unless the system demands sub-0.1% absolute accuracy at 25°C.