Texas Instruments LM4040C50IDCKR

Overview

LM4040C50IDCKR from Texas Instruments is a precision micropower shunt voltage reference with 5.0V 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-noise voltage reference in analog input modules and portable data-acquisition systems.

For engineers reviewing the LM4040C50IDCKR datasheet, LM4040C50IDCKR pinout, LM4040C50IDCKR application, or LM4040C50IDCKR equivalent, key selection criteria include its SC-70-5 package, –40°C to 85°C industrial temperature range, no-output-capacitor requirement, and compatibility with high-EMI environments via optional pin 3 connection.

Technical Context

The LM4040C50IDCKR operates as a two-terminal shunt reference, sinking cathode current (IZ) to maintain a stable 5.0V reverse breakdown voltage across its cathode-anode terminals. Its Zener-zap trimmed architecture achieves ±0.5% initial tolerance at 25°C and maintains tight regulation over 45μA–15mA IZ and –40°C to 85°C ambient.

It features low dynamic impedance (0.9Ω typical at 1mA), thermal hysteresis of 0.08%, and long-term stability of 120ppm after 1000 hours. The device requires no external capacitor and remains stable with all capacitive loads - a critical advantage for space-constrained, low-power sensor signal chains.

Key Specifications

Pinout & Package

LM4040C50IDCKR is packaged in a 5-pin SC-70 (DCK) package measuring 2.00mm × 1.25mm. Pin 1 is Anode (ground reference), Pin 2 is Cathode (voltage output node), Pin 3 is NC (no internal connection; float or tie to anode in high-EMI environments), and Pins 4–5 are NC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM4040C50IDCKR, LM4040C50IDBZR offers identical performance in a larger SOT-23 package without EMI-mitigation pin, while MAX6008AEUR+T delivers superior accuracy and noise at the cost of higher minimum cathode current - making LM4040C50IDCKR optimal for ultra-low-power, space-constrained, or EMI-prone applications.

Availability

LM4040C50IDCKR is available at Aetrix Electronics and suitable for analog input modules, portable data-acquisition systems, and field transmitters requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for LM4040C50IDCKR 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 specializing in analog and embedded processing technologies, with leadership in precision analog ICs and industrial-grade components.

The LM4040 series was designed for high-accuracy, low-power shunt reference applications in industrial, automotive, and portable instrumentation - prioritizing micropower operation, small footprint, and robustness across temperature and load variations.

FAQ

What is the operating temperature range for LM4040C50IDCKR?

The LM4040C50IDCKR is characterized for operation over the industrial temperature range of –40°C to +85°C. This range is explicitly specified in TI's official datasheet for the "I" suffix variant (LM4040C50I), and the DCK package designation confirms this grade. It is not rated for the extended –40°C to +125°C range used by "Q" grade variants like LM4040C50Q.

Does LM4040C50IDCKR require an external output capacitor?

No, LM4040C50IDCKR does not require an external output capacitor. Its internal design ensures stability with all capacitive loads, including direct connection to ADC input capacitors or long PCB traces. This eliminates BOM cost and layout complexity - a key advantage confirmed in TI's datasheet Section 3 and Section 8.2.

What is the purpose of Pin 3 on LM4040C50IDCKR?

Pin 3 on LM4040C50IDCKR is a no-connect (NC) terminal with no internal bond. TI recommends floating it or connecting it to the Anode (Pin 1) in high-EMI environments - such as near transformers or switching regulators - to reduce noise coupling into the reference node, as documented in Figure 5-2 and Table 5-1 of the datasheet.

How does the 100ppm/°C temperature coefficient affect LM4040C50IDCKR accuracy?

The 100ppm/°C temperature coefficient means LM4040C50IDCKR's output voltage drifts by up to ±0.05V over a 100°C span (e.g., –40°C to +60°C). Combined with its ±0.5% initial tolerance (±25mV at 5.0V), total worst-case error remains within ±0.55% across its full –40°C to +85°C operating range - verified in TI's overtemperature tolerance calculations in Section 6.5 footnote (2).

Can LM4040C50IDCKR be used in battery-powered applications?

Yes, LM4040C50IDCKR is specifically optimized for battery-powered applications. With a typical minimum cathode current of 45μA and stable operation down to that level, it enables multi-year operation from coin cells or primary lithium batteries in portable meters, sensors, and IoT edge nodes - a core design goal stated in TI's product description and Section 3.