L4937N

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

The L4937N is a monolithic dual voltage regulator designed for microcomputer-controlled systems, particularly in automotive applications. It features two low-dropout outputs: Output 1 provides a precise 5V standby voltage with ±2% tolerance and 50mA current capability, while Output 2 tracks the standby output and delivers up to 500mA. The device includes an integrated power-on reset circuit that senses the standby output voltage, with delay timing defined by an external capacitor. It operates with a transient supply voltage up to 40V and maintains very low quiescent current, less than 250µA, in standby mode. Protection features include thermal shutdown and short-circuit protection.

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

• Dual low-dropout linear regulators with independent current capabilities of 50mA and 500mA
• Integrated power-on reset function triggered by standby output voltage sensing
• Output 2 tracking capability allowing synchronized operation with the primary 5V standby rail
• Robust protection mechanisms including thermal shutdown and short-circuit limiting

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

• Microcomputer-controlled system power supplies
• Automotive electronic control units (ECUs)
• Standby power management circuits
• Systems requiring precise voltage regulation with reset functionality

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

Verify component authenticity through authorized STMicroelectronics distributors or certified partners. Confirm package integrity and pin alignment against the Heptawatt-7 specification. Check manufacturing date codes and RoHS compliance status as the part may be discontinued. Ensure storage conditions meet moisture sensitivity level requirements before soldering. Request original datasheets and test reports to validate performance parameters.

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

Select this component when designing systems requiring a dedicated 5V standby rail alongside a higher-current main supply. The L4937N is suitable for applications needing integrated reset generation without additional discrete components. Consider the 40V transient voltage rating for automotive environments. Evaluate thermal dissipation requirements given the Heptawatt-7 package and expected load currents. Verify that the external capacitor for reset delay meets timing specifications.

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

The L4937N belongs to STMicroelectronics' family of multifunction voltage regulators tailored for embedded control systems. It integrates multiple functions typically requiring separate ICs, simplifying board layout. The device complements other L49xx series regulators offering similar dual-output architectures. Its design focuses on reducing component count and improving reliability in space-constrained automotive and industrial modules.

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

The L4937NPD is a documented variant within the same product line. Verify pin compatibility and electrical parameter equivalence before substitution. Confirm that any alternative device matches the specific reset threshold and tracking characteristics required by the design.