Moteur de recherche de fiches techniques de composants électroniques |
|
TEA1791T Fiches technique(PDF) 3 Page - NXP Semiconductors |
|
TEA1791T Fiches technique(HTML) 3 Page - NXP Semiconductors |
3 / 11 page TEA1791T_1 © NXP B.V. 2009. All rights reserved. Product data sheet Rev. 01 — 3 February 2009 3 of 11 NXP Semiconductors TEA1791T GreenChip synchronous rectifier controller 7. Functional description 7.1 Introduction The TEA1791T is the controller for synchronous rectification to be used in discontinuous conduction mode and quasi-resonant flyback converters. 7.2 Start-up and UnderVoltage LockOut (UVLO) The IC leaves the undervoltage lockout state and activates the synchronous rectifier circuitry as soon as the voltage on the VCC pin is above 8.5 V (typ). As soon as the voltage drops below 8.0 V (typ), the undervoltage lockout state is reentered and the SR driver output is actively kept low. 7.3 Synchronous rectification After a negative voltage ( −310 mV typ) is sensed on the SRSENSE pin, the driver output voltage is driven HIGH and the external MOSFET is switched on. As soon as the SRSENSE voltage rises to −55 mV the driver output voltage is regulated to maintain the −55 mV on the SRSENSE pin. As soon as the SRSENSE voltage is above −12 mV, the driver output is pulled to ground. After switch-on of the SR MOSFET, the input signal on the SRSENSE pin is blanked for 2 µs (typ). This eliminates false switch-off due to high frequency ringing at the start of the secondary stroke. Because the driver output voltage is reduced as soon as the voltage on the SRSENSE pin is −55 mV, the external power switch can be switched off quickly when the current through the switch reaches zero. With this zero current switch-off, no separate standby mode is needed to maintain high efficiency during the no-load operation. The zero current is detected by sensing a −12 mV level on the SRSENSE pin (see Figure 3). |
Numéro de pièce similaire - TEA1791T |
|
Description similaire - TEA1791T |
|
|
Lien URL |
Politique de confidentialité |
ALLDATASHEET.FR |
ALLDATASHEET vous a-t-il été utile ? [ DONATE ] |
À propos de Alldatasheet | Publicité | Contactez-nous | Politique de confidentialité | Echange de liens | Fabricants 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 |