Electronic Components Datasheet Search |
|
FPF2003 Datasheet(PDF) 10 Page - Fairchild Semiconductor |
|
FPF2003 Datasheet(HTML) 10 Page - Fairchild Semiconductor |
10 / 12 page 10 www.fairchildsemi.com FPF2000-FPF2007 Rev. H Application Information Typical Application Input Capacitor To limit the voltage drop on the input supply caused by transient in-rush currents when the switch turns-on into a discharged load capacitor or a short-circuit, a capacitor needs to be placed between VIN and GND. A 4.7µF ceramic capacitor, CIN, must be placed close to the VIN pin. A higher value of CIN can be used to further reduce the voltage drop experienced as the switch is turned on into a large capacitive load. Output Capacitor A 0.1µF capacitor COUT, should be placed between VOUT and GND. This capacitor will prevent parasitic board inductances from forcing VOUT below GND when the switch turns-off. For the FPF2000-FPF2002 and the FPF2004-FPF2006, the total output capacitance needs to be kept below a maximum value, COUT(max), to prevent the part from registering an over-current condition and turning-off the switch. The maximum output capacitance can be determined from the following formula, Due to the integral body diode in the PMOS switch, a CIN greater than COUT is highly recommended. A COUT greater than CIN can cause VOUT to exceed VIN when the system supply is removed. This could result in current flow through the body diode from VOUT to VIN. Power Dissipation During normal operation as a switch, the power dissipation is small and has little effect on the operating temperature of the part. The parts with the higher current limits will dissipate the most power and that will only be, If the part goes into current limit the maximum power dissipation will occur when the output is shorted to ground. For the FPF2000, FPF2001, FPF2004 and FPF2005, the power dissipation will scale by the Auto-Restart Time, tRESTART, and the Over Current Blanking Time, tBLANK, so that the maximum power dissipated is, When using the FPF2002 and FPF2006 attention must be given to the manual resetting of the part. Continuously resetting the part at a high duty cycle when a short on the output is present can cause the temperature of the part to increase. The junction temperature will only be allowed to increase to the thermal shutdown threshold. Once this temperature has been reached, toggling ON will not turn-on the switch until the junction temperature drops. For the FPF2003 and FPF2007, a short on the output will cause the part to operate in a constant current state dissipating a worst case power as calculated in (3) until the thermal shutdown activates. It will then cycle in and out of thermal shutdown so long as the ON pin is active and the short is present. Board Layout For best performance, all traces should be as short as possible. To be most effective, the input and output capacitors should be placed close to the device to minimize the effects that parasitic trace inductances may have on normal and short-circuit operation. Using wide traces for VIN, VOUT and GND will help minimize parasitic electrical effects along with minimizing the case to ambient thermal impedance. OFF ON ON VIN GND FPF2000 - FPF2007 FLAGB VOUT LOAD 1.8V-5.5V C1 = 4.7µF R1 = 100KΩ C2 = 0.1µF R2 = 500Ω COUT ILIM max () t BLANK min () × VIN -------------------------------------------------------------------- = (1) PILIM () 2 RDS × 0.2 () 2 0.7 × 28mW == = (2) Pmax () tBLANK tRESTART tBLANK + --------------------------------------------------- x VIN max () ()xI LIM max () == 10 80 10 + ------------------- 5.5 × 0.2 × 1.22mW = (3) = |
Similar Part No. - FPF2003 |
|
Similar Description - FPF2003 |
|
|
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 |