Diodes Incorporated LM4040B30FTA

Overview

LM4040B30FTA from Diodes Incorporated is a precision 3.0V shunt voltage reference in SOT23 package, featuring ±0.2% initial tolerance at +25°C, 20ppm/°C max temperature coefficient over –40°C to +125°C, and stable operation across 60µA–15mA cathode current. It serves as a compact, low-noise (35µVRMS, 10Hz–10kHz) reference for ADC/DAC biasing, portable power monitoring, and battery voltage regulation circuits.

For engineers reviewing the LM4040B30FTA datasheet, LM4040B30FTA pinout, LM4040B30FTA application, or LM4040B30FTA equivalent, key selection criteria include its guaranteed 3.0V reverse breakdown voltage at 100µA, no-output-capacitor-required stability, and SOT23 footprint compatibility with space-constrained embedded systems requiring long-term drift <120ppm over 1000 hours.

Technical Context

The LM4040B30FTA operates as a two-terminal shunt reference: anode connects to system ground, cathode to regulated node via series resistor. Its bandgap core delivers fixed 3.0V reverse breakdown with minimal dependence on operating current-ΔV_R/ΔI_R ≤ 0.4mV over 60µA–1mA and ≤2.7mV over 1mA–15mA at +25°C.

Thermal hysteresis is limited to 0.08%, and dynamic impedance remains ≤0.4Ω at 1mA/120Hz. The device tolerates capacitive loads without oscillation due to internal compensation, eliminating need for external output capacitance-a critical advantage in low-power sensor nodes and battery-backed data loggers.

Key Specifications

Pinout & Package

SOT23-3 package (JEDEC MO-215AA), 2.9mm × 1.3mm × 1.0mm body, lead-free and RoHS compliant. Pin 3 (anode) must be left floating or tied to pin 2 (cathode); pin 1 is cathode. Die attachment to pin 3 creates inherent electrical connection between pins 2 and 3-correct layout prevents unintended shorts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLVH431AIDBZR and MAX6003EUR+T, the LM4040B30FTA offers superior temperature stability (20ppm/°C vs. ≥75ppm/°C) and lower minimum operating current (60µA vs. ≥100µA), making it optimal for battery-critical, wide-temperature industrial sensing where fixed 3.0V accuracy is mandatory.

Availability

LM4040B30FTA is available at Aetrix Electronics and suitable for battery-powered instrumentation, portable communications devices, and precision data acquisition systems requiring stable component supply with full traceability and lifecycle management.

Supply support for LM4040B30FTA 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

Diodes Incorporated is a global semiconductor company specializing in discrete, analog, and mixed-signal solutions, with design centers in Asia, Europe, and the US, serving industrial, computing, consumer, and communications markets.

The LM4040 series targets precision analog subsystems demanding micro-power, high accuracy, and robust thermal performance-designed specifically for space-constrained, battery-sensitive applications where traditional three-terminal references are impractical.

FAQ

What is the minimum cathode current required for LM4040B30FTA to maintain regulation?

The LM4040B30FTA requires a minimum cathode current of 60µA at +25°C to achieve specified 3.0V output and ±0.2% tolerance. At –40°C to +125°C, this rises to 70µA. Below this threshold, reverse breakdown voltage drops nonlinearly and temperature coefficient degrades significantly-designers must size the series resistor to guarantee ≥70µA under worst-case low-VS and high-IL conditions.

Can LM4040B30FTA drive a 10nF capacitive load without instability?

Yes-the LM4040B30FTA is internally compensated to remain stable with capacitive loads up to at least 1µF, as confirmed by Diodes' typical characteristics showing flat impedance vs. frequency plots with 1.0µF tantalum. A 10nF load introduces negligible phase shift; no series resistance or isolation is needed, simplifying layout in high-frequency sensor interfaces.

How does the pin configuration differ between SOT23 and obsolete SC70-5 packages?

The LM4040B30FTA uses SOT23-3 with pins 1 (cathode), 2 (cathode), and 3 (anode). In contrast, the EOL SC70-5 (H5) variant has five pins: pins 1/2/5 as cathode, pin 3 as anode, and pin 4 unused. SOT23's 3-pin layout reduces routing complexity and eliminates unused terminals, while SC70-5 required careful pin 4 floating-making SOT23 the only supported package for new designs.

Is LM4040B30FTA qualified for automotive applications?

No-LM4040B30FTA is rated for industrial temperature range (–40°C to +125°C) but lacks AEC-Q100 qualification. For automotive use, Diodes offers the LM4040Q series (e.g., LM4040Q30FTA), which undergoes additional stress testing, PPAP documentation, and failure analysis per AEC-Q100 Rev G, with identical electrical specs but automotive-specific traceability and lot control.