Electronic Components Datasheet Search |
|
SC4911 Datasheet(PDF) 7 Page - Semtech Corporation |
|
SC4911 Datasheet(HTML) 7 Page - Semtech Corporation |
7 / 14 page 7 2006 Semtech Corp. www.semtech.com SC4911 POWER MANAGEMENT 48V TO 12V FLYBACK CONVERTER AS AUXILIARY SUPPLY Figure 2 shows a simple bias supply using the SC4911. This 36 - 72V input flyback power supply employs primary side regulation from the transformer bias winding, which eliminates the need of opto coupler and secondary reference error amplifier. This is best for low cost applications requiring isolation and narrow load variation range on the secondary. During the start-up, the input source trickle charges the capacitor C1 through start-up resistor R1. As long as voltage across C1 reaches the Vcc turn-on threshold, the SC4911 turns on abruptly and start driving the gate of MOSFET Q1. After the SC4911 starts up the primary bias winding supplies the primary circuitry. Typical Applications The output of the T1 bias winding is rectified, filtered by C1 and is fed to the FB through feedback resistor R5 and R7. The output voltage on the secondary is proportional to the bias voltage by the turns ratio of the output to the bias winding. C7 and R9 are for frequency compensation. An additional small capacitor could be used from COMP to GND if it is needed. The LUVLO pin monitors the input voltage via resistor R2 and R4 to determine turn-on and turn-off of the converter. Capacitor C5 helps filter out the noise from the input line. Figure 2. 48V to 12V Flyback Converter as Auxiliary Supply R1 100K C7 47nF Vin = 48V Vpri = 12V R4 100K R2 2.7MEG C5 100pF R9 4.7K C8 1000pF D1 1N5819 Vo = 12V Q1 Si2320DS U1 SC4911 1 2 3 4 5 6 7 8 LUVLO RT FB COMP ILIM GND OUT VCC T1 3 5 8 10 2 1 R8 1.00 C3 10uF D2 1N5819 R7 100K R5 383K R3 68 R6 51 C4 0.1uF C6 150pF C1 10uF C2 100uF R10 100K |
Similar Part No. - SC4911 |
|
Similar Description - SC4911 |
|
|
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 |