STMicroelectronics LM4040DECT-3.0

Overview

LM4040DECT-3.0 from STMicroelectronics is a precision micropower shunt voltage reference delivering a stable 3.0 V output with ±1% initial accuracy at 25 °C, 70 ppm/°C max temperature coefficient, and ultra-low 10 µA operating current. It operates across -40 to +125 °C and is packaged in SOT323-5L for space-constrained industrial sensing and portable data acquisition systems.

For engineers reviewing the LM4040DECT-3.0 datasheet, LM4040DECT-3.0 pinout, LM4040DECT-3.0 application, or LM4040DECT-3.0 equivalent, key selection criteria include shunt reference stability under capacitive loads, low-frequency noise (10 µVp-p), minimum regulation current (12 µA at -40°C), and thermal hysteresis (120 ppm).

Technical Context

The LM4040DECT-3.0 functions as a two-terminal shunt reference, sinking current through its cathode to maintain precise 3.0 V across its terminals. Its bandgap-based core achieves high stability without requiring external biasing, and it remains functional with capacitive loads up to 1 µF per stability analysis.

It exhibits low dynamic impedance (0.15–0.3 Ω) and minimal voltage drift over temperature and operating current-ΔVk/ΔIk ≤ 4 mV across 1–15 mA and ΔVk/ΔT ≤ 70 ppm/°C-enabling use in high-resolution ADC references and battery-monitoring circuits where supply headroom is limited.

Key Specifications

Pinout & Package

SOT323-5L package: 1.35 mm × 1.25 mm × 0.95 mm body, 5-pin outline with 2 NC pins; optimized for high-density PCB layouts and reflow compatibility.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431ACDBVR and MAX6003EUR+T, LM4040DECT-3.0 offers the lowest operating current (10 µA) and smallest SOT323-5L footprint-critical for ultra-low-power, space-limited designs-while trading off initial accuracy and TC for cost and size efficiency.

Availability

LM4040DECT-3.0 is available at Aetrix Electronics and suitable for portable battery monitoring, industrial data acquisition, medical sensor calibration, and automotive cabin controller designs requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for LM4040DECT-3.0 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, MCU, power, and sensing solutions for industrial, automotive, and consumer markets.

The LM4040 series belongs to ST's precision analog portfolio, engineered specifically for low-power, high-stability shunt reference applications in harsh-environment instrumentation and portable electronics.

FAQ

What is the minimum cathode current required for regulation at -40 °C?

The LM4040DECT-3.0 requires a minimum cathode current of 12 µA at -40 °C to maintain regulation, as specified in Table 3 of the DS13886 datasheet. This value increases to 25 µA for 3.0 V versions across the full -40 to +125 °C range when Ik > 3.0 V, ensuring stable operation in cold-start industrial environments.

Can LM4040DECT-3.0 drive a 100 nF capacitor directly without oscillation?

Yes-Figure 11 (Stability plane vs. Cout) in the DS13886 datasheet confirms stable operation with up to 1 µF output capacitance at Ik ≥ 10 µA. At 100 nF and Ik = 12 µA, the device operates well within the stable region, eliminating need for series resistance or isolation components in filtering networks.

How does the NC pin configuration affect PCB layout?

Pins 2, 4, and 5 in the SOT323-5L package are unconnected and must either remain floating or be tied to the anode (Pin 3). This allows flexible routing-e.g., using Pin 2 as a thermal relief pad or grounding adjacent traces-without electrical impact, while maintaining mechanical stability during reflow soldering.

Is the 3.0 V output trimmed at wafer or package level?

The 3.0 V output is laser-trimmed at the wafer level during final test, as confirmed by ST's LM4040 characterization methodology in Section 3 of DS13886. This ensures ±1% initial accuracy (LM4040D grade) is achieved prior to packaging, with post-package shifts controlled by the 70 ppm/°C TC specification.