L4947L

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Overview

The L4947L is a monolithic integrated circuit in a Pentawatt package, designed as a very low drop regulator providing a fixed 5V output at up to 500mA. It features precise output voltage stability of ±4% over the full temperature range of –40°C to +125°C. The device incorporates a reset function with power-on delay defined by an external capacitor, along with robust protection against load dump (±80V), reverse voltage (–18V), short circuits, and thermal shutdown.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Feature Summary

• Provides stabilized supply voltage for automotive and industrial electronic systems with very low dropout characteristics.
• Includes a reset function that supervises output voltage, inhibiting microprocessors during out-of-regulation conditions and resetting them after a programmable delay.
• Offers comprehensive protection circuits including load dump, reverse voltage, short circuit, and thermal shutdown with hysteresis.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Applications

• Supplying microprocessor-based systems in automotive environments
• Industrial electronic system power supplies
• Applications requiring operation during battery cranking phases

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Procurement Notes

Verify component authenticity through authorized STMicroelectronics distributors or certified partners. Confirm the specific revision level matches design requirements, as specifications are subject to change without notice. Ensure proper handling procedures are followed due to ESD protection standards. Check current availability status as product lifecycle stages may affect long-term supply continuity.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Selection Notes

Select this component when a fixed 5V linear regulation is required with high current capability and integrated reset supervision. The Pentawatt package suits applications needing efficient heat dissipation. Consider the minimum 20μF external capacitor requirement for stability. Evaluate if the specific reset threshold voltages align with the target microprocessor's logic levels.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Part Context

The L4947L belongs to the L4947 series of very low drop regulators manufactured by STMicroelectronics. It utilizes a lateral PNP power transistor to achieve low dropout voltage. The device is part of a family designed specifically for harsh electrical environments found in automotive and industrial sectors, emphasizing reliability and protection features.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Replacement Considerations

The L4947R is a variant within the same series offering different reset threshold characteristics. Verify pin compatibility and electrical parameters before substitution. No other direct cross-references are documented in the provided datasheet.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators FAQ

What determines the power-on reset delay time?

The power-on reset delay time is defined by the value of the external capacitor connected to the reset function.

How does the device handle reverse voltage input?

The L4947L includes reverse voltage protection capable of withstanding up to –18V DC reverse input voltage.