ICE2HS01G Datasheet, PDF (18/29 Pages) Infineon Technologies AG – High Performance Resonant Mode Controller

High Performance Resonant Mode Controller
ICE2HS01G
Functional description
3.8 Mains Input Voltage Sense
The operation range of mains input voltage needs to be specified for LLC resonant converter. In addition, the input voltage
information is used to determines whether the SR turned on delay is added or not. The typical circuit of mains input voltage
sense and process is shown Figure 16.
Figure 16 Mains input voltage sense
With the current source I_hys connected between VINS and Ground, an adjustable hysteresis between the on and off input
voltage can be created as
V_HYS = R_INSH ⋅ I_hys
[4]
The mains input voltage is divided by R_INS1 and R_INS2. A current source I_hys is connected from VINS pin to ground in the IC.
If the on and off threshold for mains voltage is V_mainon and V_mainoff, the resistors can be decided as
R_INSH
=
V-----_{m---a--i--n--o---n---–-----V----m----a--i-n--o---f-f}
I_hys
[5]
R_INSL
=
R_INSH
⋅
-------------V-----^I-^N----^S--^O---^N--------------
V_mainoff – V_INSON
[6]
The blanking time for leaving brown-out is around 450µs and for entering brown-out is around 47µs. For example,
if R_INS1=6.2MΩ and R_INS2=27kΩ, the turn-on bus voltage is 350V and the turn-off bus voltage is 288V.
3.9 Over load protection
In the typical application circuit, a voltage divider with R_FT1 and R_FT2, is connected to the collector of optocoupler,
and this divided voltage is delivered to LOAD pin. This is used to determine the feedback voltage threshold for
over load protection. During operation, if V_LOAD > 1.8V, and this condition last longer than an adjustable blanking
time of T_OLP, the IC will immediately stop delivering all the driving signals, and only after an adjustable restart time
T_restart , IC will restart with soft start. This allows the system to face a sudden power surge for a short period of time
without triggering the protection.
The Timer pin is used to set the blanking time T_OLP and restart time T_restart for over load protection. The RC parallel
circuit, C_T and R_T, is connected to this pin. When the voltage on load pin is higher than V_load, an internal current
source of I_BL starts charging the external capacitor C_T. This current source turns off only when the capacitor
voltage, V_TL reaches V_TLH or when V_LOAD decreases below 1.8V. Once V_TL exceeds 4.0V, the overload/openloop
protection is triggered by turning off the GATE signal. From this time, C_T slowly discharges through the external
resistance R_T. When V_T drops below 0.5V, the IC restarts its operation with soft-start. The charging time and the
Version 2.0
18
11 May 2010