L4938EPD

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

The L4938EPD is a monolithic integrated dual voltage regulator designed for microcomputer-controlled systems, particularly in automotive applications. It features two low dropout outputs: Output 1 provides 5 V ± 2% with 400 mA capability, while Output 2 offers a high-precision 5 V ± 1% standby output with 100 mA capability. The device includes power-on reset and input voltage sense functions. Key electrical parameters include an operating DC supply voltage range of 5 V to 28 V, with transient tolerance up to 40 V. Quiescent current is extremely low at 65 μA, rising to less than 90 μA in standby mode. The reset threshold is adjustable from 3.8 V to 4.7 V.

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

• Dual low dropout voltage regulation with independent main and high-precision standby outputs
• Integrated power-on reset function with adjustable threshold levels
• Input voltage sensing capability with negative transient protection down to -5 V
• Ultra-low quiescent current consumption optimized for battery-powered automotive environments

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

• Microcomputer-controlled systems in automotive electronics
• Power management for engine control units requiring standby modes
• Voltage regulation for embedded controllers with reset monitoring needs

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

Verify component authenticity through authorized STMicroelectronics distributors or certified partners. Confirm the specific suffix matches the required pinout and thermal characteristics. Check for obsolescence status as indicated in official product lifecycle documents. Ensure compliance with automotive quality standards relevant to your application region. Validate package integrity upon receipt to prevent handling damage.

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

Select this component when designing automotive microcontroller power supplies requiring dual regulated rails. Choose the EPD variant for the specific package configuration offered. Consider the 400 mA main output for primary logic loads and the 100 mA precision output for sensitive reference circuits. Evaluate the adjustable reset threshold against your microcontroller's brown-out requirements. Verify that the 40 V transient rating exceeds your system's maximum expected line spikes.

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

The L4938 series belongs to STMicroelectronics' portfolio of advanced voltage regulators tailored for automotive environments. These devices integrate multiple power management functions into a single monolithic IC to reduce board space and complexity. The L4938EPD specifically addresses the need for reliable power sequencing and monitoring in harsh electromagnetic and thermal conditions typical of vehicle interiors.

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

Official documentation lists the L4938EPD as obsolete. Consult STMicroelectronics for qualified replacement part numbers within the same family or updated generations. Ensure any substitute maintains compatible pinouts, voltage ratings, and automotive qualification standards.