SLUUBZ3C EVM User's guide

SLUUBZ3C May 2020 – October 2022 LMG2610 , UCC28782

8.8 Key Switching Waveforms and Operation Mode Load Current

This section shows typical operation modes in Table 8-1 along with typical load currents in this design and with Vin = 115Vac and Vo = 20V as an example.

AAM: Adaptive Amplitude Modulation
ABM: Adaptive Burst Mode
LPM: Low Power Mode
SBP1: First Standby Power Mode
SBP2: Second Standby Power Mode

Table 8-1 Operation Mode and Load Current at 20-V Output and 115Vac Input

Mode	AAM	ABM	LPM	SBP1	SBP2	Survival
Burst Frequency, f_BUR	Not Applicable	> 25kHz (2 to 9 pulses)	about 25kHz (2 pulses)	8.5kHz to 25kHz (2 pulses)	< 8.5kHz (2 pulses)	about 8 pulses
Typical Load Current	1.8 A to 3.25 A	0.5 A to 1.8 A	0.2 A to 0.5 A	0.1 A to 0.2 A	< 0.1 A	Not Applicable

Figure 8-9 Typcial Waveform in AAM Operation Yellow = PWML, Red = PWMH, Green = Transformer Primary Winding Current (0.2 V/A), Blue = Switch Node Voltage

Figure 8-11 Typical Waveform in ABM Operation Yellow = PWML, Red = Vgs of SR MOSFET, Green = Transformer Primary Winding Current (0.2 V/A), Blue = Switch Node Voltage

Figure 8-10 Typical Waveform in ABM Operation Yellow = PWML, Red = PWMH, Green = Transformer Primary Winding Current (0.2 V/A), Blue = Switch Node Voltage

Figure 8-12 Typical Waveform in LPM Operation Yellow = PWML, Red = PWMH, Green = Transformer Primary Winding Current (0.2 V/A), Blue = Switch Node Voltage

Figure 8-13 Typical Waveform in SBP1 Operation Yellow = PWML, Red = PWMH, Green = Transformer Primary Winding Current (0.2 V/A), Blue = Switch Node Voltage

Figure 8-14 Typical Waveform in SBP2 Operation Yellow = PWML, Red = PWMH, Green = Transformer Primary Winding Current (0.2 V/A), Blue = Switch Node Voltage