19.4
19.58
19.76
19.94
20.12
20.3
20.48
75
105
135
165
195
225
255
V
o
u
t,
V
AC Input Voltage, Vac
Full Load
Performance Data and Typical Characteristic Curves
10
SLUUBV6 – August 2018
Copyright © 2018, Texas Instruments Incorporated
Using the UCC28780EVM-021, 45-W, 20-V High-Density Silicon (Si) Based,
Active-Clamp Flyback Converter/Evaluation Module
5.3
VI Characteristics
Figure 7. V
OUT
Line Regulation
Figure 8. V
OUT
Load Regulation
5.4
Switching Frequency
Figure 9. Switching Frequency Over Input at Full Load
Figure 10. Maximum switching frequency about 500kHz at
high line and entering ABM
CH1 = PWML, CH4 = Transformer Primary Winding Current, CH3 = Switch Node Voltage
5.5
Key Switching Waveforms and Operation Mode Load Current
This section shows typical operation modes in
along with typical load currents in this design and
with Vin = 115Vac as an example.
•
AAM: Adaptive Amplitude Modulation
•
ABM: Adaptive Burst Mode
•
LPM: Lower Power Mode
•
SBP: Standby Power Mode
Table 4. Operation Mode and Load Current
Mode
AAM
AAM to ABM
ABM End
LPM
SBP
Typical Load Current
1.50 A to 2.25 A
1.30 A to 1.60 A
0.15 A to 0.18 A
0.05 A to 0.15 A
< 0.08 A
Typical Load %
67% to 100%
58% to 71%
6.7% to 8%
2.2% to 6.7%
< 3.5%