Electronic Components Datasheet Search
  English  ▼

X  

Preview PDF HTML

AN2644 Datasheet(PDF) 57 Page - STMicroelectronics

Part # AN2644
Description  An introduction to LLC resonant
PDF  64 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  STMICROELECTRONICS [STMicroelectronics]
Direct Link  http://www.st.com
Logo STMICROELECTRONICS - STMicroelectronics

AN2644 Datasheet(HTML) 57 Page - STMicroelectronics

Back Button AN2644 Datasheet HTML 53Page - STMicroelectronics AN2644 Datasheet HTML 54Page - STMicroelectronics AN2644 Datasheet HTML 55Page - STMicroelectronics AN2644 Datasheet HTML 56Page - STMicroelectronics AN2644 Datasheet HTML 57Page - STMicroelectronics AN2644 Datasheet HTML 58Page - STMicroelectronics AN2644 Datasheet HTML 59Page - STMicroelectronics AN2644 Datasheet HTML 60Page - STMicroelectronics AN2644 Datasheet HTML 61Page - STMicroelectronics Next Button
Zoom Inzoom in Zoom Outzoom out
 57 / 64 page
background image
AN2644
Power MOSFET effective Coss and half-bridge midpoint's transition times
57/64
Figure 36.
Schematization of Q2 turn-off transient
This charge will be partly stored in CStray and partly in Coss. The charge in CStray will
obviously be CStray·Vin, then the one stored in Coss will be given by (Equation 47)
substituting Vin in VHB:
Equation 51
A linear capacitance CHB equivalent to CHB(Vin) will have the same total charge QT stored in
it when its voltage equals Vin. Then it is possible to write:
Equation 52
which yields:
Equation 53
The capacitance value defined by (Equation 53) has to be used in calculations related to
transition time of the node HB, as far as ZVS is concerned.
As previously stated, to achieve ZVS the transition of the node HB must be completed within
the deadtime TD inserted between the transitions from one state to the other of either
switch, that is, TT ≤ TD. Combining (Equation 46) and (Equation 48) and solving for TT:
Equation 54
Depending on the data available, (Equation 54) can be used for finding either the minimum
value of IR0 (called IRmin in the text) or the maximum value of CHB or the minimum value of
TD .
t
ICHB
IR0
QT
IQ2
t
IR0
Tf
TT
VHB
t
Vin
Actual
Approx.
t
ICHB
IR0
QT
IQ2
t
IR0
Tf
TT
VHB
t
Vin
Actual
Approx.
Qoss V
in
()
20 V
inCoss25
=
Q
T
C
StrayVin
20 V
inCoss25
C
HBVin
=
+
=
C
HB
C
Stray
20
V
in
------------C
oss25
+
=
T
T
T
f
2
-----
C
StrayVin
20 V
inCoss25
+
I
R0
---------------------------------------------------------------------
T
f
2
-----
C
HBVin
I
R0
-------------------
T
D
≤
+
=
+
=



Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64


Datasheet Download

Go To PDF Page


Link URL



Does ALLDATASHEET help your business so far?  [ DONATE ] 

About Alldatasheet   |   Advertisement   |   Contact us   |   Privacy Policy   |   Link to Datasheet    |   Link Exchange   |   Manufacturer List
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com