Diodes Incorporated LM4040D30FTA

Overview

LM4040D30FTA from Diodes Incorporated is a precision 3.0V shunt voltage reference in SOT23 package, rated for ±1% initial tolerance at +25°C, 60µA–15mA operating current, and −40°C to +125°C temperature range. It delivers stable reference voltage for analog-to-digital conversion, battery monitoring, and portable power management circuits where space-constrained PCB layout and low-power operation are critical.

For engineers reviewing the LM4040D30FTA datasheet, LM4040D30FTA pinout, LM4040D30FTA application, or LM4040D30FTA equivalent, key selection criteria include reverse breakdown voltage accuracy, temperature coefficient (≤100 ppm/°C), dynamic output impedance (≤1.2 Ω), noise performance (35 µVRMS), and capacitive load stability without external compensation.

Technical Context

The LM4040D30FTA operates as a two-terminal bandgap-based shunt reference, requiring only an external series resistor to regulate voltage across a load. Its internal architecture maintains regulation by sinking variable current through the cathode-anode path while holding reverse breakdown voltage tightly at 3.0V under varying load and supply conditions.

It achieves thermal stability via curvature-compensated bandgap design, with typical temperature coefficient of 20 ppm/°C (−40°C to +125°C) and thermal hysteresis of 0.08%. The device tolerates unlimited capacitive loads and exhibits low dynamic impedance (0.4 Ω at 1mA, 120Hz), enabling use in high-precision feedback loops without oscillation risk.

Key Specifications

Pinout & Package

The LM4040D30FTA is housed in a RoHS-compliant SOT23 surface-mount package (3-pin, 2.9 mm × 1.3 mm footprint). Pin 1 is Anode, Pin 2 is Cathode, and Pin 3 is NC (no connect) but electrically tied to Pin 2 internally; it must be left floating or connected to Pin 2 per layout guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL431ACDBVR and MAX6003EUR+T, the LM4040D30FTA offers superior temperature range (−40°C to +125°C), wider operating current (60µA–15mA), and guaranteed capacitive-load stability - making it optimal for ruggedized, space-constrained, and wide-temperature embedded systems.

Availability

LM4040D30FTA is available at Aetrix Electronics and suitable for battery-powered equipment, precision power supplies, and portable instrumentation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LM4040D30FTA 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 for industrial, computing, consumer, and communications markets.

The LM4040 series belongs to Diodes' precision analog portfolio, designed specifically for space-constrained, low-power, high-stability voltage reference applications in portable and harsh-environment electronics.

FAQ

What is the minimum operating current for LM4040D30FTA at +25°C?

The LM4040D30FTA requires a minimum reverse current of 62 µA at +25°C to maintain regulation within specification. This value increases to 70 µA over the full −40°C to +125°C range, ensuring reliable startup and stability in cold-weather or high-temperature deployments.

Can LM4040D30FTA drive a 1µF ceramic capacitor directly?

Yes - the LM4040D30FTA is explicitly designed to remain stable with unlimited capacitive loading, including 1µF ceramic capacitors. No series resistance or isolation is required, unlike many other shunt references that oscillate or exhibit ringing under such conditions.

How does the 1% initial tolerance impact system calibration?

A ±1% initial tolerance at +25°C translates to ±30 mV absolute error at 3.0V output. In systems using 12-bit ADCs with 3.3V full-scale range, this introduces ≤12 LSB of fixed offset error - correctable via one-point factory calibration or compensated digitally in firmware.

Is LM4040D30FTA pin-compatible with earlier SC70-5 variants?

No - the LM4040D30FTA uses the SOT23-3 package (3-pin), while SC70-5 variants (e.g., LM4040D30H5TA) have five pins and different pin mapping. The SC70-5 versions are end-of-life; migration to SOT23 requires PCB layout revision and verification of thermal performance due to differing thermal resistance (θJA = 380°C/W).