Diodes Incorporated LM4041CQFTA

Overview

LM4041CQFTA from Diodes Incorporated is an AEC-Q100 Grade 1 qualified precision shunt voltage reference delivering a fixed 1.225 V output with ±0.5% initial tolerance at 25°C, 20 ppm/°C max temperature coefficient over –40°C to +125°C, 20 µV_RMS noise (10 Hz–10 kHz), and stable operation from 60 µA to 12 mA supply current - used in automotive sensor signal conditioning and battery monitoring circuits.

For engineers reviewing the LM4041CQFTA datasheet, LM4041CQFTA pinout, LM4041CQFTA application, or LM4041CQFTA equivalent, key selection criteria include automotive-grade reliability, low-noise micro-power operation, SOT23 package compatibility, and shunt topology suitability for space-constrained biasing and feedback networks.

Technical Context

The LM4041CQFTA implements a bandgap-based shunt reference architecture optimized for high stability under capacitive loading and wide current variation. It maintains regulation across 60 µA–12 mA reverse current while exhibiting only 20 ppm/°C typical TC and <2.5 mV drift over –40°C to +125°C.

No external capacitor is required for stability, and its dynamic impedance remains ≤2.0 Ω at 1 mA (120 Hz). The device supports both fixed 1.225 V output and adjustable variants via external resistor dividers, with cathode voltage sensitivity of –1.55 mV/V at 25°C.

Key Specifications

Pinout & Package

LM4041CQFTA uses the SOT23-3 package (JEDEC TO-236AB), with die attached to pin 1. Pin 1 (Anode) and pin 2 (Cathode) are internally connected; pin 1 must be left floating or tied to pin 2. Pin 3 is NC (No Connect).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM4041CFTA, LM4041CQFTA adds automotive qualification without sacrificing accuracy or noise; versus TLVH431ACDBVR, it delivers superior TC and simpler implementation for fixed 1.225 V use cases.

Availability

LM4041CQFTA is available at Aetrix Electronics and suitable for automotive sensor modules, battery management systems, and industrial data loggers requiring stable component supply with AEC-Q100 Grade 1 assurance.

Supply support for LM4041CQFTA 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 manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and precision analog solutions.

The LM4041 series targets automotive and industrial applications demanding precision, low power, and robust thermal performance - designed specifically for shunt reference roles in harsh-environment sensor and measurement systems.

FAQ

What is the maximum cathode voltage the LM4041CQFTA can regulate?

The LM4041CQFTA is a shunt reference and does not regulate cathode voltage directly; instead, it maintains 1.225 V across its terminals when reverse-biased. Its absolute maximum cathode-to-anode voltage is 15 V for the adjustable variant, but the fixed 1.225 V version operates within system voltage rails limited by external series resistor and load conditions - typical use keeps cathode voltage near 1.225 V.

Can LM4041CQFTA drive a 10 kΩ load directly?

No - as a shunt reference, LM4041CQFTA sinks current rather than sourcing it. To interface with a 10 kΩ load referenced to ground, the load must be placed between cathode and ground, with a series resistor from supply to cathode. At 1.225 V, a 10 kΩ load draws 122.5 µA; the series resistor must supply ≥182.5 µA (load + 60 µA min reference current) to maintain regulation.

Is pin 3 of LM4041CQFTA electrically connected internally?

No - pin 3 is designated NC (No Connect) in the SOT23-3 package. It is not bonded to the die and has no internal connection. It must remain unconnected on the PCB to avoid mechanical stress or unintended coupling; solder mask should fully cover this pad.

How does LM4041CQFTA compare to LM4040 in terms of temperature coefficient?

LM4041CQFTA specifies ≤100 ppm/°C max over –40°C to +125°C, with typical performance at ±20 ppm/°C. The LM4040C (1.225 V) has a tighter 50 ppm/°C max spec but lacks AEC-Q100 qualification and offers only commercial temperature range (–40°C to +85°C), making LM4041CQFTA more suitable for extended-temperature automotive applications despite slightly relaxed TC limits.