 |
Moteur de recherche de fiches techniques de composants électroniques |
|
|
Moteur de recherche de fiches techniques de composants électroniques |
|
FAN2013MPX Fiches technique(PDF) 6 Page - Fairchild Semiconductor |
|
||||||||||||||||||||||||||||||
FAN2013MPX Fiches technique(HTML) 6 Page - Fairchild Semiconductor |
|
|
6 / 9 page  © 2006 Fairchild Semiconductor Corporation www.fairchildsemi.com FAN2013 Rev. 1.0.0 6 Block Diagram Figure 10. Block Diagram Operation Description The FAN2013 is a step-down pulse-width modulated (PWM) current mode converter with a fixed switching fre- quency of 1.3MHz. At the rising edge of each clock cycle, the P-channel transistor is turned on until the PWM comparator trips or the current limit is reached. During the ON time, the inductor current ramps up and is monitored by the internal current-mode control loop. After a minimum dead time, the N-channel transistor is turned ON and the inductor current ramps down. As the clock cycle is completed, the N-channel switch is turned OFF and the next clock cycle starts. The duty cycle is given by the ratio of output voltage and input voltage. The converter runs at minimum duty cycle when output voltage is at minimum and input voltage is at maximum, and at 100% duty cycle when the input voltage approaches the output voltage, as described below. 100% Duty Cycle Operation As the input voltage approaches the output voltage and the duty cycle exceeds the typical 95%, the converter turns the P-channel transistor continuously on. In this mode, the output voltage is equal to the input voltage, minus the voltage drop across the P-channel transistor: VOUT = VIN – ILOAD × (RDS_ON + RL) where RDS_ON = P-channel switch ON resistance ILOAD = Output current RL = Inductor DC resistance UVLO and Soft Start The internal voltage reference, VREF, and the IC remain reset until VIN reaches the 3.7V UVLO threshold. The FAN2013 has an internal soft-start circuit that limits the in-rush current during start-up. This prevents possi- ble voltage drops of the input voltage and eliminates the output voltage overshoot. The soft-start is implemented as a digital circuit, increasing the switch current in four steps to the P-channel current limit (3.5A). Typical start- up time for a 40µF output capacitor with a load current of 2.0A is 800µs. Output Over-Voltage Protection When output voltage, VOUT, reaches approximately 7% above the nominal value, the device turns OFF the P- channel switch and turns ON part of the N-channel tran- sistor with a built-in current limit of about 400mA. When VOUT reaches the hysteresis of about 2%, the device starts switching normally in closed loop. If output voltage is pulled up by an external voltage source with a current limit higher than typical 400mA, the output voltage stays up at the external voltage source level. The over-voltage protection is designed to limit the out- put voltage excursion in case of a transient response from full load to a minimum load. Output Short-Circuit Protection The switch peak current is limited cycle by cycle to a typ- ical value of 3.5A. In the event of an output voltage short circuit, the device operates with a frequency of 400kHz and minimum duty cycle, making the average typical input current .45A. Thermal Shutdown When the die temperature exceeds 150°C, a reset occurs and remains in effect until the die cools to 130°C, when the circuit is allowed to restart. FB ERROR AMP REF FB IS CURRENT SENSE DIGITAL SOFT START UNDER VOLTAGE LOCKOUT LOGIC CONTROL MOSFET DRIVER OSC SLOPE COMPENSATION COMP OVER VOLTAGE COMP IS GND SW PVIN PG GND 0.8V PG COMP GND REF FB VIN EQ 1 |
Numéro de pièce similaire - FAN2013MPX |
|
Description similaire - FAN2013MPX |
|
|
|
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 |
French ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
