UC3856NG4

DC DC Switching Controllers Overview

The UC3856NG4 is an improved current-mode PWM controller manufactured by Texas Instruments, designed for high-performance power conversion applications. It supports multiple topologies including Boost, Buck, Flyback, Forward, Full Bridge, Half Bridge, and Push-Pull configurations. The device operates with a switching frequency of 200 kHz and features a maximum duty cycle of 47%. It provides two output channels with a drive capability of 1.5 A and includes a 5.1 V reference voltage. The unit functions within a supply voltage range of 7V to 40V and operates reliably across a temperature range of 0°C to +70°C.

DC DC Switching Controllers Feature Summary

• Integrated synchronous rectifier control for enhanced efficiency in appropriate topologies
• Clock synchronization capability allows for precise timing alignment in multi-controller systems
• Includes soft-start functionality to limit inrush current during startup sequences
• Supports frequency control for flexible system design and noise management

DC DC Switching Controllers Applications

• High-efficiency DC-DC converter designs utilizing synchronous rectification
• Power factor correction (PFC) pre-regulator circuits
• Industrial power supplies requiring robust current-mode control
• Telecommunications power systems using various isolated topologies

DC DC Switching Controllers Procurement Notes

Verify the specific suffix 'G4' indicates lead-free composition and RoHS compliance as per manufacturer standards. Confirm package dimensions match the 16-PDIP specification with a 0.300-inch width. Ensure the operating environment stays within the specified 0°C to +70°C thermal range. Check for moisture sensitivity handling requirements if the component has been exposed to ambient conditions beyond its shelf life limits.

DC DC Switching Controllers Selection Notes

Select this component when synchronous rectification is required alongside standard PWM control. The 200 kHz frequency offers a balance between size and efficiency. Verify that the 1.5 A output drive current meets the gate charge requirements of the external MOSFETs. Consider the 47% maximum duty cycle limitation when designing boost or flyback converters to ensure adequate headroom for regulation.

DC DC Switching Controllers Part Context

This part belongs to the UC3856 series of improved current-mode PWM controllers from Texas Instruments. It shares functional similarities with the UC1856 and UC2856 variants, differing primarily in temperature rating and manufacturing process. The NG4 suffix specifically denotes a lead-free, RoHS-compliant version packaged in a standard 16-pin PDIP housing suitable for through-hole mounting.

DC DC Switching Controllers Replacement Considerations

• UC3856N

DC DC Switching Controllers FAQ

Does the UC3856NG4 support synchronous rectification?

Yes, the datasheet confirms the integration of a synchronous rectifier driver, allowing for improved efficiency in compatible topologies.

What is the maximum duty cycle for this controller?

The maximum duty cycle is specified as 47%, which must be considered when selecting it for boost or flyback converter designs.