Texas Instruments LM4040A50IDCKR

Overview

LM4040A50IDCKR from Texas Instruments is a precision micropower shunt voltage reference with 5.0V nominal output, ±0.1% initial accuracy (A grade), 100ppm/°C temperature coefficient, 35μVRMS wideband noise, and stable operation from 45μA to 15mA cathode current - used in high-accuracy analog input modules and data-acquisition front-ends.

For engineers reviewing the LM4040A50IDCKR datasheet, LM4040A50IDCKR pinout, LM4040A50IDCKR application, or LM4040A50IDCKR equivalent, key selection criteria include initial tolerance at 25°C, thermal drift over –40°C to 85°C, dynamic impedance under varying load current, noise performance in low-power signal chains, and SC-70 package compatibility with space-constrained PCB layouts.

Technical Context

The LM4040A50IDCKR operates as a two-terminal shunt reference, sinking cathode current to maintain a precise 5.0V reverse breakdown voltage across its terminals. Its Zener-zap trimmed bandgap core delivers tight initial accuracy without external components, and it remains stable with all capacitive loads - eliminating need for output capacitance.

Designed for industrial temperature operation (–40°C to +85°C), it achieves 100ppm/°C max temperature coefficient via on-die compensation and exhibits low 0.3Ω typical dynamic impedance at 1mA, enabling high PSRR in ratiometric ADC systems and low-error sensor excitation circuits.

Key Specifications

Pinout & Package

LM4040A50IDCKR is packaged in a 5-pin SC-70 (DCK) outline measuring 2.00mm × 1.25mm. The device has three functional terminals and two no-connect pins.

Key Features

Applications

Equivalent & Alternatives

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

Compared with REF3050AIDBZR and ADR3450ARJZ-R7, LM4040A50IDCKR provides the lowest minimum operating current and capacitor-free stability - making it optimal for ultra-low-power, space-constrained, and cost-sensitive industrial analog designs where ±0.1% initial accuracy is sufficient.

Availability

LM4040A50IDCKR is available at Aetrix Electronics and suitable for analog input modules, field transmitters, and energy infrastructure monitoring requiring stable component supply with guaranteed long-term manufacturability.

Supply support for LM4040A50IDCKR 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 company delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The LM4040 series was designed specifically for high-accuracy, low-power shunt reference applications - targeting data acquisition, sensor signal conditioning, and portable instrumentation where size, stability, and micropower operation are critical.

FAQ

What is the maximum operating temperature range for LM4040A50IDCKR?

The LM4040A50IDCKR is characterized for operation from –40°C to +85°C (industrial temperature range). It is not rated for the extended –40°C to +125°C range - that specification applies only to Q-grade variants like LM4040C50Q. Using LM4040A50IDCKR beyond +85°C risks exceeding its specified electrical parameters and long-term reliability limits.

Does LM4040A50IDCKR require an external output capacitor?

No, LM4040A50IDCKR is stable with all capacitive loads and does not require an external output capacitor. This is confirmed in the official TI datasheet Section 3 ("Description") and Section 8.2 ("Typical Applications"). Adding capacitance will not degrade performance but provides no benefit - simplifying design and reducing BOM count in space-constrained applications.

What is the cathode current range for proper regulation of LM4040A50IDCKR?

LM4040A50IDCKR regulates correctly within a cathode current range of 45μA (minimum, typical) to 15mA (maximum, absolute rating). Operation below 45μA may cause loss of regulation or increased output drift; operation above 15mA exceeds absolute maximum ratings and risks permanent damage. Designers must select the series current-limiting resistor to maintain I_Z within this window across all input voltage and load conditions.

How does the pin configuration of LM4040A50IDCKR differ from the SOT-23 version?

LM4040A50IDCKR uses a 5-pin SC-70 (DCK) package with Cathode on Pin 3, Anode on Pin 1, and NC on Pins 4 and 5. In contrast, the SOT-23 (DBZ) variant has only 3 pins: Cathode on Pin 1, Anode on Pin 2, and a third pin marked "*" (must float or tie to anode). The DCK layout accommodates tighter routing in dense layouts but requires attention to unused pins - they must remain unconnected unless EMI mitigation dictates grounding Pin 2.

Can LM4040A50IDCKR replace LM4040B50IDCKR in an existing design?

Yes, LM4040A50IDCKR can directly replace LM4040B50IDCKR because both share identical pinout, package, and electrical behavior except for initial accuracy (±0.1% vs. ±0.2%) and temperature coefficient (both 100ppm/°C max). No PCB or schematic changes are needed - the upgrade improves reference precision at no cost penalty, provided the tighter tolerance adds value to the system's overall accuracy budget.