SLUAAF9
September 2021
UCC28782
Trademarks
1
Initial Board Visual Inspection and Start-up Check
2
Typical System Operating Waveforms
2.1
SBP2 Mode
2.2
SBP1 Mode
2.3
LPM mode
2.4
LPM to ABM Mode Transition
2.5
ABM Mode
2.6
ABM to AAM Mode Transition
2.7
AAM Mode
3
Typical System Protection Waveforms
3.1
Over-Power Protection (OPP)
3.2
Output Overvoltage Protection (OVP)
3.3
Output Short-Circuit Protection (SCP)
4
Common Issues and Solutions
4.1
VDD Boost Converter Survival Mode
4.1.1
Survival Mode Due To Boost Inductor DCR Too High.
4.1.2
System Stays In Survival Mode When the Output Voltage is Low Such as 3.3V/5V/9V
4.2
10% Load Efficiency Might not Meet spec. in USB-PD Application, Especially at 5 V/9 V Output Condition
4.3
Transient
4.3.1
BIN/BSW Pin Damage During LPM to ABM Mode Transition
4.3.2
SR MOSFET VDS Overstress at Survival Mode
4.3.3
SR MOSFET Vds Voltage Overstress Due to PWMH Partial Turn On At Load Transition
5
References
5
References
Texas Instruments,
UCC28782 High Density Active Clamp Flyback Controller with EMI Dithering, X-Cap Discharge, and Bias Power Management
data sheet.
Texas Instruments,
Debugging UCC28780 ACF Converter Start-up Issues
application note.
Texas Instruments,
Using the UCC28782EVM-030 65-W USB-C PD High-Density Active-Clamp Flyback Converter
user guide.