ICE2HS01G Datasheet, PDF (16/29 Pages) Infineon Technologies AG – High Performance Resonant Mode Controller

High Performance Resonant Mode Controller
ICE2HS01G
Functional description
as well. The resistor R_CL can be adjusted to find the suitable reducing speed of SR on time. The relationship between CS
voltage and CL voltage is shwon in Figure 14.
7.5
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
30
40
50
60
70
80
90
Rs r d(k Ω)
Figure 13 SR on time versus SRD resistance
Figure 14 Relationship between V_CS and V_CL
3.7.2
Turn-on delay
When the input voltage is too high, the LLC converter secondary switches are working in CCM condition. Certain recovery
time of the MOSFET body diode is required depending on the turn-off current. For better performance, the other MOSFET
should be turned on after the recovery phase. The turn-on delay function is built in ICE2HS01G for such purpose. When the
VINS pin voltage is higher than Vres pin, the SR MOSFETs are turned on 250ns after the corresponding primary MOSFETs
are turned on.
3.7.3
Turn-off delay
The SR on time control determines the conduction time for secondary switches and the duration is actually link to resonant
parameters and output load. However, the SR on time can not be longer than the primary gate signals, which otherwise will
cause damage to the system. Therefore, SR gate will be turned off by two conditions: the primary gate signal or the SR on
time oscillator, the one comes first will determine the actual SR duation.
However, the delay from IC gate signal to secondary SR switches can be longer than those delay to primary SR swithes. The
function turn-off delay is used to adjust this difference. Instead of using the primary gate signal (PHG/PLG) to turn off SR
gate, a signal with certain advance time to primary gate signal is used to generate SR gate off signal. And this certain advance
time is adjustable through delay pin resistor.
Version 2.0
16
11 May 2010