SLUS270G March 1999 – May 2020 UCC2800 , UCC2801 , UCC2802 , UCC2803 , UCC2804 , UCC2805
PRODUCTION DATA
- 1 Features
- 2 Applications
- 3 Description
- 4 Revision History
- 5 Description (continued)
- 6 Device Comparison Table
- 7 Pin Configuration and Functions
- 8 Specifications
-
9 Detailed Description
- 9.1 Overview
- 9.2 Functional Block Diagram
- 9.3
Feature Description
- 9.3.1 Detailed Pin Description
- 9.3.2 Undervoltage Lockout (UVLO)
- 9.3.3 Self-Biasing, Active Low Output
- 9.3.4 Reference Voltage
- 9.3.5 Oscillator
- 9.3.6 Synchronization
- 9.3.7 PWM Generator
- 9.3.8 Minimum Off-Time Setting (Dead-Time Control)
- 9.3.9 Leading Edge Blanking
- 9.3.10 Minimum Pulse Width
- 9.3.11 Current Limiting
- 9.3.12 Overcurrent Protection and Full Cycle Restart
- 9.3.13 Soft Start
- 9.3.14 Slope Compensation
- 9.4 Device Functional Modes
- 10Application and Implementation
- 11Power Supply Recommendations
- 12Layout
- 13Device and Documentation Support
- 14Mechanical, Packaging, and Orderable Information
9.3.9 Leading Edge Blanking
A 100-ns leading edge blanking interval is applied to the current sense input circuitry of the UCC280x devices. This internal feature has been incorporated to eliminate the requirement for an external resistor-capacitor filter network to suppress the switching spike associated with turnon of the power MOSFET. This 100-ns period must be adequate for most switch-mode designs but can be lengthened by adding an external R/C filter. Note that the 100-ns leading edge blanking is also applied to the cycle-by-cycle current limiting function in addition to the overcurrent fault comparator.
Figure 9-13 Current Sense Filter Required With Older PWM ICs
Figure 9-14 Current Sense Waveforms With Leading Edge Blanking