Electronic Components Datasheet Search
  English  ▼
ALLDATASHEET.COM

X  

FAN7930C Datasheet(PDF) 13 Page - Fairchild Semiconductor

Part # FAN7930C
Description  Critical Conduction Mode PFC Controller
Download  22 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  FAIRCHILD [Fairchild Semiconductor]
Direct Link  http://www.fairchildsemi.com
Logo FAIRCHILD - Fairchild Semiconductor

FAN7930C Datasheet(HTML) 13 Page - Fairchild Semiconductor

Back Button FAN7930C Datasheet HTML 9Page - Fairchild Semiconductor FAN7930C Datasheet HTML 10Page - Fairchild Semiconductor FAN7930C Datasheet HTML 11Page - Fairchild Semiconductor FAN7930C Datasheet HTML 12Page - Fairchild Semiconductor FAN7930C Datasheet HTML 13Page - Fairchild Semiconductor FAN7930C Datasheet HTML 14Page - Fairchild Semiconductor FAN7930C Datasheet HTML 15Page - Fairchild Semiconductor FAN7930C Datasheet HTML 16Page - Fairchild Semiconductor FAN7930C Datasheet HTML 17Page - Fairchild Semiconductor Next Button
Zoom Inzoom in Zoom Outzoom out
 13 / 22 page
background image
© 2010 Fairchild Semiconductor Corporation
www.fairchildsemi.com
FAN7930C • Rev. 1.0.0
13
valley position of MOSFET voltage stress. For valley
detection, a minor delay by the resistor and capacitor is
needed. A capacitor increases the noise immunity at the
ZCD pin. If ZCD voltage is higher than 1.5V, an internal
ZCD comparator output becomes HIGH and LOW when
the ZCD goes below 1.4V. At the falling edge of
comparator output, internal logic turns on the MOSFET.
Figure 29.
Auxiliary Voltage Threshold
When no ZCD signal is available, the PFC controller
cannot turn on the MOSFET, so the controller checks
every switching off time and forces MOSFET turn on
when the off time is longer than 150μs. This is called the
restart timer, which triggers MOSFET turn-on at startup
and may be used at the input voltage zero-cross period.
s
150
μ
Figure 30.
Restart Timer at Startup
Because the MOSFET turn-on depends on the ZCD
input, switching frequency may increase to higher than
several megahertz due to the miss-triggering or noise
on the nearby ZCD pin. If the switching frequency is
higher than needed for critical conduction mode (CRM),
operation mode shifts to continuous conduction mode
(CCM). In CCM, unlike CRM where the boost inductor
current is reset to zero at the next switch on; inductor
current builds up at every switching cycle and can be
raised to very high current that exceeds the current
rating of the power switch or diode. This can seriously
damage the power switch and result in burn down. To
avoid this, maximum switching frequency limitation is
embedded. If ZCD signal is applied again within 3.3μs
after the previous rising edge of gate signal, this signal
is ignored internally and FAN7930C waits for another
ZCD signal. This slightly degrades the power factor
performance at light load and high input voltage.
Figure 31.
Maximum Switching Frequency
Limit Operation
5. Control: The scaled output is compared with the
internal reference voltage and sinking or sourcing
current is generated from the COMP pin by the
transconductance amplifier. The error amplifier output is
compared with the internal sawtooth waveform to give
proper turn-on time based on the controller.
Figure 32.
Control Circuit
Unlike a conventional voltage-mode PWM controller,
FAN7930C turns on the MOSFET at the falling edge of
ZCD signal. On-instance is determined by the external
signal and the turn-on time lasts until the error amplifier
output (VCOMP) and sawtooth waveform meet. When
load is heavy, output voltage decreases, scaled output
decreases, COMP voltage increases to compensate low
output, turn-on time lengthens to give more inductor
turn-on time, and increased inductor current raises the
output voltage. This is how PFC negative feedback
controller regulates output.
The maximum of VCOMP is limited to 6.5V, which dictates
the maximum turn-on time, and switching stops when
VCOMP is lower than 1.0V.


Similar Part No. - FAN7930C

ManufacturerPart #DatasheetDescription
logo
ON Semiconductor
FAN7930C ONSEMI-FAN7930C Datasheet
982Kb / 22P
   Critical Conduction Mode PFC Controller
December-2017, Rev. 3
FAN7930CMX-G ONSEMI-FAN7930CMX-G Datasheet
982Kb / 22P
   Critical Conduction Mode PFC Controller
December-2017, Rev. 3
More results

Similar Description - FAN7930C

ManufacturerPart #DatasheetDescription
logo
Fairchild Semiconductor
AN-6961 FAIRCHILD-AN-6961 Datasheet
434Kb / 8P
   Critical Conduction Mode PFC Controller
FAN7930B FAIRCHILD-FAN7930B Datasheet
944Kb / 22P
   Critical Conduction Mode PFC Controller
FAN7529 FAIRCHILD-FAN7529 Datasheet
1Mb / 20P
   Critical Conduction Mode PFC Controller
FAN7529 FAIRCHILD-FAN7529_07 Datasheet
1Mb / 20P
   Critical Conduction Mode PFC Controller
FAN7530 FAIRCHILD-FAN7530_07 Datasheet
1Mb / 20P
   Critical Conduction Mode PFC Controller
logo
ON Semiconductor
FAN7930B ONSEMI-FAN7930B Datasheet
1Mb / 22P
   Critical Conduction Mode PFC Controller
September-2017, Rev. 2
logo
Alpha & Omega Semicondu...
AOZ7111 AOSMD-AOZ7111 Datasheet
912Kb / 15P
   Critical Conduction Mode PFC Controller
logo
Fairchild Semiconductor
FAN7530 FAIRCHILD-FAN7530 Datasheet
2Mb / 20P
   Critical Conduction Mode PFC Controller
logo
ON Semiconductor
FAN7930C ONSEMI-FAN7930C Datasheet
982Kb / 22P
   Critical Conduction Mode PFC Controller
December-2017, Rev. 3
logo
Fairchild Semiconductor
FAN7930MX FAIRCHILD-FAN7930MX Datasheet
1Mb / 22P
   FAN7930 Critical Conduction Mode PFC Controller
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22


Datasheet Download

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ] 

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   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