Texas Instruments LM4040D25IDCKRG4

Overview

LM4040D25IDCKRG4 from Texas Instruments is a precision micropower shunt voltage reference delivering a fixed 2.5 V output with ±25 mV (1.0%) initial tolerance at 25°C, 150 ppm/°C temperature coefficient, 35 μVRMS wideband noise, and stable operation from 45 μA to 15 mA cathode current in the SC-70-5 package. It serves as a compact, low-noise reference for high-resolution ADCs and sensor signal conditioning in industrial field transmitters.

For engineers reviewing the LM4040D25IDCKRG4 datasheet, LM4040D25IDCKRG4 pinout, LM4040D25IDCKRG4 application, or LM4040D25IDCKRG4 equivalent, key selection criteria include its D-grade accuracy, extended –40°C to 85°C operating range, no-output-capacitor requirement, and SC-70 footprint compatibility with space-constrained analog front-ends.

Technical Context

The LM4040D25IDCKRG4 operates as a two-terminal shunt reference, sinking cathode current (IZ) to maintain a precise 2.5 V reverse breakdown voltage across its terminals. Its Zener-zap trimmed silicon design achieves 1.0% initial accuracy and 150 ppm/°C thermal drift over temperature, with dynamic impedance under 1.1 Ω at 1 mA enabling stable regulation under varying load conditions.

It requires no external capacitor for stability and supports all capacitive loads - a critical advantage in noisy industrial environments where layout constraints preclude added filtering. The device's low 45 μA minimum cathode current enables use in battery-powered instrumentation without compromising reference stability.

Key Specifications

Pinout & Package

LM4040D25IDCKRG4 is packaged in a 5-pin SC-70 (DCK) outline measuring 2.00 mm × 1.25 mm. This surface-mount package supports automated assembly and offers thermal performance suitable for industrial ambient conditions.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM4040C25IDCKR and TLVH431ACDBVR, LM4040D25IDCKRG4 trades absolute accuracy for lower cost and zero external components - ideal for cost-optimized industrial sensors where 1% tolerance is sufficient and board space is constrained.

Availability

LM4040D25IDCKRG4 is available at Aetrix Electronics and suitable for industrial field transmitters, energy infrastructure monitoring systems, and analog input modules requiring stable component supply with guaranteed long-term manufacturability.

Supply support for LM4040D25IDCKRG4 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 and embedded processing technologies, with decades of expertise in precision reference design and high-reliability industrial ICs.

The LM4040 series was engineered specifically for cost-sensitive, space-constrained analog signal chains in industrial automation, process control, and test equipment - prioritizing micropower operation, no-capacitor stability, and robust thermal performance.

FAQ

What is the operating temperature range for LM4040D25IDCKRG4?

The LM4040D25IDCKRG4 is characterized for operation from –40°C to +85°C ambient temperature. This industrial-grade range supports deployment in factory-floor controllers, outdoor utility meters, and HVAC sensor nodes without derating. Its 150 ppm/°C temperature coefficient ensures predictable drift behavior across this full span, and thermal hysteresis remains below 0.08% after cycling between extremes. The device does not support the extended –40°C to +125°C range offered by Q-grade variants like LM4040D25Q.

Does LM4040D25IDCKRG4 require an output capacitor?

No, LM4040D25IDCKRG4 is inherently stable with all capacitive loads and requires no output capacitor for proper operation. This eliminates a common source of layout-induced instability and reduces bill-of-materials count in compact designs such as handheld test equipment and modular I/O cards. The internal Zener-zap trimmed structure and low dynamic impedance (<1.1 Ω) ensure phase margin remains adequate even when driving long PCB traces or ADC input capacitance directly.

How does the 1.0% initial tolerance of LM4040D25IDCKRG4 impact system accuracy?

The ±25 mV (1.0%) initial tolerance of LM4040D25IDCKRG4 directly contributes to DC offset error in the signal chain - for example, causing up to ±1 LSB error in a 12-bit 2.5 V full-scale ADC. In systems where absolute accuracy is critical, this error is typically compensated via one-time factory calibration. However, in cost-sensitive applications like industrial 4–20 mA transmitters, the D-grade tolerance is intentionally selected to balance performance against BOM cost and size, especially when combined with digital correction algorithms.

What is the minimum cathode current needed for LM4040D25IDCKRG4 to regulate properly?

The LM4040D25IDCKRG4 requires a minimum cathode current of 45 μA (typical) at 25°C to maintain regulation within specification. At temperature extremes (–40°C or +85°C), the minimum rises to 80 μA. This ultra-low requirement enables use with high-value pull-up resistors (e.g., 100 kΩ from 5 V) or direct drive from micropower op-amps, making it suitable for battery-operated wireless sensors and energy-harvesting nodes where quiescent current must remain sub-100 μA.

Can LM4040D25IDCKRG4 replace LM4040D25IDBVR in a design?

LM4040D25IDCKRG4 and LM4040D25IDBVR share identical electrical specifications and D-grade performance, but differ in package: DCKRG4 uses SC-70-5 (5-pin), while DBVR uses SOT-23-3 (3-pin). Pin compatibility is not maintained - the SC-70 variant has two NC pins and a dedicated anode pin, whereas the SOT-23 version integrates anode and cathode on adjacent pins with no NCs. Layout redesign and solder paste stencil updates are required for substitution; electrical validation is recommended due to minor parasitic differences.