Infineon TLE4274GV50 5V Low-Dropout Voltage Regulator: Features and Application Circuits

In the realm of power management for automotive and industrial electronics, the demand for robust, reliable, and efficient voltage regulation is paramount. The Infineon TLE4274GV50 stands out as a quintessential solution, a 5V low-dropout (LDO) voltage regulator engineered to meet the stringent requirements of these demanding environments. This integrated circuit provides a stabilized 5V output from a higher input voltage, ensuring critical microcontrollers, sensors, and logic circuits operate with a clean and stable power supply.

Key Features of the TLE4274GV50

The TLE4274GV50 is packed with features that make it a preferred choice for designers. Its core characteristic is its very low dropout voltage, typically 200 mV at a full load current of 450 mA. This allows it to continue regulating the output voltage effectively even when the input voltage dips very close to 5V, maximizing useful battery life and operational range.

Beyond basic regulation, the device incorporates a suite of comprehensive protection features. These include:

Overcurrent Protection: Safely limits the output current in case of a short circuit or overload.

Overtemperature Protection: Shuts down the regulator if the junction temperature exceeds safe limits, preventing thermal damage.

Reverse Polarity Protection: Withstands a reversed input voltage of up to -40V for a limited time, a critical feature for automotive applications where jump-starting is common.

Overvoltage Protection (Load Dump): Can endure transient input voltages as high as 45V, protecting both the regulator and the load from voltage spikes typical in automotive electrical systems.

Furthermore, the IC offers excellent low quiescent current performance, both in normal operation and in its low-power standby mode, which is controlled by a dedicated enable pin. Additional functionalities like a reset output with a configurable delay time provide a defined signal to a microcontroller upon power-up or during a voltage drop (brown-out), ensuring a safe and controlled system start-up sequence.

Typical Application Circuits

The TLE4274GV50 is designed for simplicity of use, requiring only a few external components for most applications. A standard application circuit is straightforward.

1. Basic Regulation Circuit:

The most common setup involves connecting input and output capacitors. A ceramic or electrolytic capacitor (e.g., 10µF to 100µF) on the input side (VIN) is essential for stabilizing the input supply and filtering high-frequency noise. Similarly, a capacitor on the output side (VQ) is required for loop stability and improving transient response. The value, typically between 10µF and 47µF, should be chosen based on the application's load transient requirements. The enable pin (EN) can be tied directly to VIN for always-on operation or driven by a logic signal from a microcontroller to enter low-power standby mode.

2. Circuit with External Reset Delay Configuration:

A key advantage of this LDO is its integrated reset generator. The timing of the reset signal is set by an external capacitor (CR) connected to the CDELAY pin. The value of this capacitor directly determines the delay time between the output voltage reaching a stable 5V and the reset signal going high. This allows designers to tailor the start-up sequence to the specific needs of the downstream microcontroller.

3. High-Current and Thermal Considerations:

For applications drawing the full 450 mA current, proper PCB layout is crucial. The ground pin must be connected to a large copper plane to aid heat dissipation. The use of an external pass transistor is not required, as the device integrates a powerful output stage. However, if the power dissipation (calculated as (VIN - VQ) IQ) becomes excessive, a heatsink may be necessary to keep the junction temperature within safe limits.

ICGOODFIND Summary

The Infineon TLE4274GV50 is a highly integrated, robust, and feature-rich 5V LDO regulator. Its exceptional combination of low dropout voltage, extensive protection mechanisms (reverse polarity, overvoltage, overtemperature), and a programmable reset output makes it an ideal, single-chip power management solution for harsh electrical environments, particularly in automotive electronics. Its simple application design minimizes external component count, reducing both board space and overall system cost.

Keywords: Low-Dropout (LDO) Regulator, Automotive Grade, Reverse Polarity Protection, Reset Generator, Load Dump Protection