L4949DG

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

The L4949DG is a monolithic integrated 5.0 V low dropout (LDO) voltage regulator manufactured by onsemi, designed for microcomputer-controlled systems. It features an operating DC supply voltage range of 5 V to 28 V and can withstand transient supply voltages up to 40 V. The device provides an output current capability of up to 100 mA with a very low dropout voltage of less than 0.5 V. Key integrated functions include a power-on reset circuit that senses the output voltage and a programmable reset pulse delay via an external capacitor. Additionally, it incorporates an uncommitted voltage sense comparator for input monitoring.

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

• Integrates a power-on reset circuit that monitors the regulated output voltage to ensure system stability during startup or brown-out conditions.
• Includes an uncommitted voltage sense comparator capable of detecting input voltage levels, providing additional monitoring flexibility for system control.
• Features extremely low quiescent current in standby mode and high precision output voltage regulation to maintain efficiency and accuracy.
• Provides comprehensive protection mechanisms including thermal shutdown and short-circuit protection to safeguard the device under fault conditions.

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

• Microcomputer-controlled systems requiring stable 5V logic supplies
• Automotive electronic applications due to AEC-Q100 qualification
• Systems requiring input voltage monitoring via the sense comparator
• Circuits needing reliable power-on reset sequencing

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

Verify the specific suffix 'DG' against official onsemi documentation to confirm package type and temperature grade. Ensure the selected variant matches the required automotive qualification standards if used in vehicle electronics. Cross-reference the datasheet revision date to confirm feature availability, particularly regarding the reset delay programming and sense comparator functionality. Confirm lead-free and RoHS compliance status as specified in the product ordering information.

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

Select the L4949DG when a fixed 5V output with integrated reset and sensing capabilities is required. Consider this component for designs where board space is limited due to its monolithic integration of regulator, reset, and comparator functions. Evaluate the 100mA output current limit against peak load requirements. Verify that the input voltage range of 5V to 28V aligns with the system's power source characteristics.

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

The L4949 series belongs to onsemi's family of low dropout linear regulators designed for robust performance in demanding environments. These devices are specifically engineered for automotive and industrial applications where reliability and precise voltage regulation are critical. The integration of microprocessor control functions like reset and watchdog timers reduces the need for external components, simplifying the overall system design.

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

Consult official onsemi substitution guides for verified alternatives. Generic LDO replacements may lack the integrated reset and sense comparator features. Ensure any substitute part maintains compatibility with the 5V output requirement and the DIP-8 package if physical footprint constraints exist.