 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
FSFR18003 Datasheet(PDF) 10 Page - Fairchild Semiconductor |
|
||||||||||||||||||||||||||||||
FSFR18003 Datasheet(HTML) 10 Page - Fairchild Semiconductor |
|
|
10 / 16 page  © 2007 Fairchild Semiconductor Corporation www.fairchildsemi.com FSFR2100 • 1.0.0 10 cycles, which adds 40kHz to the initial frequency of the external soft-start circuit, as shown in Figure 20. Thus, the initial frequency of the soft-start is given as: min 5.2 5.2 ( ) 100 40 ( ) ISS SS kk f kHz RR ΩΩ =+ × + (3) It is typical to set the initial frequency of soft-start 2~3 times the resonant frequency (fO) of the resonant network. The soft-start time is determined by the RC time constant as: SS SS SS TR C =⋅ (4) f s time Control loop take over 40kHz f ISS Figure 20. Frequency Sweeping of Soft-start 4. Control Pin : The FSFR-series has a control pin that can be used for protection, cycle skipping, and remote on/off. Figure 21 shows the internal block diagram for control pin. OLP LVcc good CON LVcc OVP + - + - -Q Q R S Auto-restart protection + - 0.6V/0.4V 5V LVcc I delay 2 Stop switching Figure 21. Internal Block of Control Pin Protection : When the control pin voltage exceeds 5V, protection is triggered. Detailed applications are described in the protection section. Pulse Skipping : FSFR-series stops switching when the control pin voltage drops below 0.4V and resumes switching when the control pin voltage rises above 0.6V. To use pulse-skipping, the control pin should be connected to the opto-coupler collector pin. The frequency that causes pulse skipping is given as: ( ) kHz 100 x R k 16 . 4 R k 2 . 5 max min SKIP + = (5) Figure 22. Control Pin Configuration for Pulse Skipping Remote On / Off : When an auxiliary power supply is used for standby, the main power stage using FSFR- series can be shut down by pulling down the control pin voltage, as shown in Figure 23. R1 and C1 are used to ensure soft-start when switching resumes. OP1 R min FPS Main Output Main Off Aux Output R1 C1 OP1 Figure 23. Remote On / Off Circuit 5. Protection Circuits : The FSFR-series has several self-protective functions, such as Overload Protection (OLP), Over-Current Protection (OCP), Abnormal Over- Current Protection (AOCP), Over-Voltage Protection (OVP), and Thermal Shutdown (TSD). OLP, OCP, and OVP are auto-restart mode protections, while AOCP and TSD are latch-mode protections, as shown in Figure 24. Auto-restart Mode Protection: Once a fault condition is detected, switching is terminated and the MOSFETs remain off. When LVcc falls to the LVcc stop voltage of 11V, the protection is reset. The FPS resumes normal operation when LVcc reaches the start voltage of 14V. |
Similar Part No. - FSFR18003 |
|
Similar Description - FSFR18003 |
|
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.NET |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| 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 |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
