LX1681IDM

DC DC Switching Controllers Overview

The LX1681IDM is a monolithic voltage-mode PWM controller IC designed for flexible, low-cost buck regulator implementations. It operates with a fixed switching frequency of 190kHz and requires a 5V supply voltage. The device features one positive output configured as a transistor driver within an 8-SOIC package. It supports adjustable output voltages between 1.25V and 4.5V via resistor dividers. Operating temperature ranges from 0°C to 70°C (TA). The component includes current limit and soft start control features, utilizing MOSFET RDS(ON) sensing with a 1µs delay to eliminate ringing errors.

DC DC Switching Controllers Feature Summary

• Implements non-synchronous buck step-down regulation with minimal external components
• Provides hiccup-mode fault protection to reduce average power during short-circuit conditions
• Utilizes internal MOSFET RDS(ON) voltage drop sensing for cost-effective current limiting

DC DC Switching Controllers Applications

• Flexible low-cost DC-DC switching controller designs
• Buck regulator supplies requiring adjustable output voltages
• Applications needing integrated hiccup-mode short-circuit protection

DC DC Switching Controllers Procurement Notes

Verify the specific suffix IDM against the manufacturer's official documentation to confirm the exact package type and tape/reel specifications. Confirm that the component status aligns with project requirements, as availability may be limited. Ensure that the operating temperature range meets the environmental constraints of the target application. Cross-reference the datasheet revision date to validate parameter accuracy before integration.

DC DC Switching Controllers Selection Notes

Select this component when a non-synchronous buck topology is required for cost-sensitive designs. The fixed switching frequency simplifies filter design compared to variable frequency controllers. Consider the 1µs sensing delay when evaluating high-speed transient response needs. Verify that the 5V Vcc requirement fits within the available system power rails. Evaluate the 8-SOIC package dimensions against PCB space constraints.

DC DC Switching Controllers Part Context

The LX1681IDM belongs to the LX1681/1682 family of voltage-mode PWM controllers manufactured by Microsemi Corporation. This series is engineered for efficient step-down conversion with reduced external component counts. The LX1681 variant specifically provides non-synchronous control, distinguishing it from the synchronous LX1682 model which offers higher efficiency through integrated drivers.

DC DC Switching Controllers Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.