UC3845BD1013TR

DC DC Switching Controllers Overview

The UC3845BD1013TR is a current-mode PWM controller manufactured by STMicroelectronics, designed for off-line and DC-to-DC converters. It operates in Boost or Flyback topologies with a maximum switching frequency of 500 kHz. The device features an internal oscillator trimmed for precise frequency control and under-voltage lockout thresholds of 8.5 V (on) and 7.9 V (off). It supports a maximum duty cycle of 48% via an internal toggle flip-flop that blanks the output every other clock cycle. Powered by a supply voltage range of 7.6 V to 30 V, it provides a single positive isolated output through a high-current totem-pole driver suitable for N-channel MOSFETs.

DC DC Switching Controllers Feature Summary

• Implements fixed-frequency current mode control schemes with minimal external component requirements
• Features an internal toggle flip-flop mechanism to limit maximum duty cycle below 50 percent
• Includes a precision internally trimmed reference and under-voltage lockout with hysteresis
• Provides cycle-by-cycle latching PWM protection and automatic feed-forward compensation

DC DC Switching Controllers Applications

• Off-line power supplies
• DC-to-DC converter designs
• Boost topology circuits
• Flyback transformer-based power stages

DC DC Switching Controllers Procurement Notes

Verify the specific suffix BD1013TR against official STMicroelectronics documentation to confirm package type and tape-and-reel specifications. Ensure compatibility with the required operating temperature range of negative forty degrees Celsius to one hundred fifty degrees Celsius junction temperature. Cross-reference datasheet revision levels to validate pinout consistency and electrical parameter tolerances before finalizing procurement orders.

DC DC Switching Controllers Selection Notes

Select this component when designing systems requiring a maximum duty cycle strictly limited to less than fifty percent. The UC3845 variant differs from the UC3842/UC3843 series by utilizing an internal toggle flip-flop to achieve this constraint. Verify that the lower under-voltage lockout thresholds align with the available auxiliary winding voltages in the target application circuit design.

DC DC Switching Controllers Part Context

This part belongs to the UC284xB family of current-mode PWM controllers. While sharing core architecture with the UC3845B, the UC3845BD1013TR specifies surface-mount packaging in an eight-pin SOIC format. It shares functional similarities with the UC2845BD1013TR but targets commercial temperature ranges rather than extended industrial environments.

DC DC Switching Controllers Replacement Considerations

Public confirmed substitute part numbers include TL2845BDR-8 from Texas Instruments.