UC2845D

Power Supply Controllers, Monitors Overview

The UC2845D is a high-performance current mode PWM controller designed for offline and DC-DC converter applications. It features a fixed switching frequency of 250 kHz, with operation up to 500 kHz. The device includes an internally trimmed reference, undervoltage lockout with hysteresis, and a high-current totem-pole output capable of driving power MOSFETs. It supports flyback and boost topologies with a maximum duty cycle of 48%. Operating voltage ranges from 7.6 V to 30 V, with a working temperature range of -40°C to 85°C.

Power Supply Controllers, Monitors Feature Summary

• Current mode control architecture for precise cycle-by-cycle current limiting
• Integrated oscillator with automatic feed-forward compensation
• High-current totem-pole output stage optimized for MOSFET driving
• Undervoltage lockout mechanism ensures stable startup and operation

Power Supply Controllers, Monitors Applications

• Offline flyback converters
• Forward converters
• Boost DC-DC converters
• Battery chargers

Power Supply Controllers, Monitors Procurement Notes

Verify the manufacturer marking on the component body to distinguish between ON Semiconductor, STMicroelectronics, or Texas Instruments variants, as pinouts and electrical characteristics may differ slightly. Confirm the package type matches the design requirements, typically SOIC-8 for the 'D' suffix. Check for RoHS compliance status if environmental regulations apply to the end product.

Power Supply Controllers, Monitors Selection Notes

Select this controller when a fixed 250 kHz switching frequency is required for cost-effective designs with minimal external components. It is suitable for applications needing cycle-by-cycle current limit protection and high peak drive capability. Consider alternatives if variable frequency operation or synchronous rectification control is necessary.

Power Supply Controllers, Monitors Part Context

The UC2845D belongs to the UC184/284/384xA family of high-performance current mode controllers. These devices are industry-standard solutions for isolated and non-isolated power supplies. The 'D' suffix indicates a surface-mount plastic small outline package (SOIC). This series provides a robust foundation for general-purpose power conversion circuits.

Power Supply Controllers, Monitors Replacement Considerations

• UC2845BD1R2G
• UC2845BD1

Power Supply Controllers, Monitors FAQ

What is the guaranteed oscillator frequency for the UC2845D?

The oscillator frequency is guaranteed at 250 kHz.

Does the UC2845D support synchronous rectification?

No, the UC2845D is a standard PWM controller without integrated synchronous rectification drivers.