UC3843ADX

DC DC Switching Controllers Overview

The UC3843ADX is a current-mode PWM controller manufactured by onsemi, designed for offline and DC-to-DC converter applications. It operates within an input voltage range of 10V to 30V, featuring a start-up threshold of approximately 16V and a turn-off threshold of 10V. The device supports switching frequencies up to 500 kHz, determined by external timing components. It includes an internally trimmed bandgap reference providing a stable 5.1V output. The controller offers pulse-by-pulse current limiting, under-voltage lockout with hysteresis, and a high-current totem-pole output capable of sourcing and sinking 1A.

DC DC Switching Controllers Feature Summary

• Current-mode control architecture for enhanced load response and simplified compensation
• Integrated pulse-by-pulse current limiting for power switch protection
• Under-voltage lockout mechanism with defined hysteresis to prevent erratic operation
• High-current totem-pole output stage for direct MOSFET driving

DC DC Switching Controllers Applications

• Offline flyback converters
• Forward converters
• DC-to-DC step-down regulators

DC DC Switching Controllers Procurement Notes

Verify the specific suffix 'ADX' against official onsemi documentation to confirm package type and tape-and-reel specifications. Ensure compatibility with existing PCB footprints and thermal management requirements. Confirm RoHS compliance status as per the latest datasheet revision. Validate that the component meets all environmental operating temperature ranges required for the target application.

DC DC Switching Controllers Selection Notes

Select this controller when current-mode control is preferred for its inherent line feed-forward and cycle-by-cycle current limiting. It is suitable for designs requiring high efficiency and compact magnetic components due to support for frequencies up to 500 kHz. Consider the 1A peak output drive capability for driving medium-power MOSFETs without additional gate driver stages.

DC DC Switching Controllers Part Context

The UC3843 belongs to the UC3842/3/4/5 family of current-mode PWM controllers. This family is widely used in power supply designs due to its robust feature set and ease of implementation. The UC3843 specifically targets applications requiring single-ended output control with precise current regulation capabilities.

DC DC Switching Controllers Replacement Considerations

Compatible replacements include UC3843BD1G and UC3843BNG from onsemi, which share identical electrical characteristics. Other manufacturers offer pin-compatible alternatives such as the NCP4306 or STMicroelectronics L6562, though functional differences may exist.