Infineon Technologies TLE4476D

Infineon TLE4476D Automotive Linear Regulator IC Product Summary

The Infineon TLE4476D is a highly integrated dual-output linear voltage regulator designed for demanding automotive and industrial environments. Housed in the PG-TO252-5-11 (DPAK) package, it offers two fixed positive output voltages—3.3V at 350mA and 5V at 430mA—making it a practical choice for microprocessor systems and automotive electronics requiring stable supply rails with compact form factor. The device’s dual-output configuration with independent Enable control for the 5V rail allows system designers to power peripherals or subsystems selectively, optimizing efficiency and system flexibility.

Main Functions and Protection Features of the Infineon TLE4476D

Infineon TLE4476D combines robust electrical performance with comprehensive safety protections. Its key attributes include:

Dual outputs: 3.3V (350mA) and 5V (430mA), each with ±4% accuracy.

Low dropout operation: Maximum dropout voltage of 0.7V at full load, supporting reliable performance even under low input voltage conditions.

Wide input voltage range: Operates from 4.5V (for 3.3V output) or 5.7V (for 5V output) up to 42V, supporting both cold crank and load dump scenarios typical in automotive applications.

Enable input for output 2: Allows ON/OFF switching of the 5V output, easily controlled via battery, ignition, or microcontroller logic.

Protection suite: Integrated overcurrent, overtemperature, overvoltage, reverse polarity, and short-circuit protection, as well as ESD protection in accordance with MIL Std. 883 (±2kV).

Automotive-grade reliability: AEC-Q100 qualification with a broad junction temperature range from -40°C to 170°C, ready to withstand extreme operating conditions.

Infineon TLE4476D Pin Assignment and Functional Diagram

Understanding the pin functions is essential for integration into circuit boards:

Input (I): Connects to supply voltage (up to 42V), requiring local ceramic filtering for stability.

Q1 (3.3V Output): Delivers up to 350mA; output requires ≥10μF/ESR <2Ω capacitor for regulation.

Ground (GND): Device reference point.

Q2 (5V Output): Supplies up to 430mA; output needs ≥10μF/ESR <3Ω capacitor.

Enable (EN): Logical input to activate or deactivate Q2; high-level enables the 5V rail.

Internally, the TLE4476D utilizes a bandgap reference and separate regulation circuitry for each output, managing power supply ripple rejection up to 60dB in the 20Hz–20kHz range.

Maximum Allowable Ratings for Infineon TLE4476D in Automotive Applications

The TLE4476D is engineered to handle transient and steady-state electrical stress levels encountered in automotive systems. Rated for input voltages of -42V to 42V (and up to 65V for less than 400ms during overvoltage events), both outputs are protected against voltage and current excursions. The junction can safely reach up to 170°C, a critical requirement under engine compartment placement or aggressive ambient conditions. It offers robust reverse polarity survival (up to 42V) and maintains ESD immunity up to ±2kV, minimizing application downtime and device damage.

Operational Limits and Thermal Considerations for Infineon TLE4476D

For optimal operation, the TLE4476D requires:

Input voltage: 4.5V to 42V (for 3.3V output), 5.7V to 42V (for 5V output).

Output currents: Up to 350mA for Q1 and 430mA for Q2.

Ambient and junction temperatures: -40°C to 170°C.

Thermal resistance is specified at 3K/W junction-to-case and 80K/W junction-to-ambient (with a specified PCB layout and heatsink area), supporting efficient heat dissipation strategies. Engineers should note that continuous operation at peak temperature affects device reliability, capped at 500-hour statistical lifetime in such conditions.

Electrical Specifications of the Infineon TLE4476D Dual Output Linear Regulators

Detailed electrical performance further clarifies suitability for precise applications:

3V Output (Q1): Typical voltage 3.3V (range: 3.17V–3.43V); load regulation 30mV; line regulation 20mV; current limit 350–900mA.

0V Output (Q2): Typical voltage 5V (range: 4.8V–5.2V); load and line regulation 50mV; current limit 430–900mA.

Dropout voltage: As low as 0.3V (typical), up to 0.7V at rated load.

Supply ripple rejection: 60dB across typical automotive frequencies.

Quiescent current: 100–150μA under normal conditions; up to 13mA with high load.

The Enable pin thresholds (ON: >1.8V, OFF: <1.0V) support versatile logic interfacing. Output stability depends on external capacitor ratings; selected capacitors must offer ≥10μF with ESR within designated limits for each rail.

Guidance for Integrating the Infineon TLE4476D in Applications

In real-world automotive or industrial applications, the TLE4476D facilitates robust and flexible solutions for powering microprocessors and companion ICs. Designers should connect input and output capacitors closely to the IC, ensuring stable operation across temperature and load variations. Series resistors at the input can help damp LC resonances, important for noise-sensitive environments. The selectable 5V output via EN input offers direct compatibility with battery or ignition signals as well as programmable microcontroller control, enabling tailored power-up/power-down sequences for subsystems.

Alternative or Equivalent Devices to Infineon TLE4476D

Given the obsolete status of Infineon TLE4476D, engineers and procurement specialists seeking comparable performance and footprint may consider the following approaches:

Identifying current Infineon OPTIREG™ series devices that meet automotive-grade dual output, low-dropout criteria.

Evaluating alternative automotive-grade dual-output linear regulators from other established vendors such as Texas Instruments, ON Semiconductor, or STMicroelectronics that offer similar output voltages, protection features, and packaging options.

Reviewing requirements for AEC-Q100 qualification, protection features, quiescent current, and dropout voltage to ensure compatibility in critical application scenarios.

Conclusion

: Infineon TLE4476D as a solution for high-reliability automotive voltage regulation

The Infineon TLE4476D dual linear voltage regulator remains a notable choice for automotive system designers when stable, protected, and independently switchable supply rails are required. Its range of robust protection mechanisms, flexibility of output control, and comprehensive automotive qualification enable deployment in harsh environments. Detailed understanding of its technical characteristics and integration guidelines allows engineers to leverage both performance and reliability, whether continuing with legacy designs or transitioning to new-generation equivalents in modern automotive electronics platforms.