Electronic Components Datasheet Search |
|
AP7217C Datasheet(PDF) 7 Page - Diodes Incorporated |
|
AP7217C Datasheet(HTML) 7 Page - Diodes Incorporated |
7 / 9 page AP7217C 1.25V 600mA CMOS LDO AP7217C Rev. 3 7 of 9 OCTOBER 2009 DS31424 www.diodes.com © Diodes Incorporated Application Note Input Capacitor A 1 µF ceramic capacitor is recommended to connect between IN and GND pins to decouple input power supply glitch and noise. The amount of the capacitance may be increased without limit. A lower ESR (Equivalent Series Resistance) capacitor allows the use of less capacitance, while higher ESR type requires more capacitance. This input capacitor must be located as close as possible to the device to assure input stability and less noise. For PCB layout, a wide copper trace is required for both IN and GND. Output Capacitor The output capacitor is required to stabilize and help the transient response of the LDO. The AP7217C is designed to have excellent transient response for most applications with a small amount of output capacitance. The AP7217C is stable with any small ceramic output capacitors of 1.0 µF or higher value, and the temperature coefficients of X7R or X5R type. Additional capacitance helps to reduce undershoot and overshoot during transient. For PCB layout, the output capacitor must be placed as close as possible to OUT and GND pins, and keep the leads as short as possible. ENABLE/SHUTDOWN Operation The AP7217C (SOP-8L-EP) is turned on by setting the EN pin high, and is turned off by pulling it low. If this feature is not used, the EN pin should be tied to IN pin to keep the regulator output on at all time. To ensure proper operation, the signal source used to drive the EN pin must be able to swing above and below the specified turn-on/off voltage thresholds listed in the Electrical Characteristics section under VIL and VIH. Thermal Considerations Thermal Shutdown Protection limits power dissipation in AP7217C. When the operation junction temperature exceeds 140°C, the Over Temperature Protection circuit starts the thermal shutdown function and turns the pass element off. The pass element turn on again after the junction temperature cools by 30°C. For continuous operation, do not exceed absolute maximum operation junction temperature 125°C. The power dissipation definition in device is: PD = (VIN − VOUT) x IOUT + VIN x IQ The maximum power dissipation depends on the thermal resistance of IC package, PCB layout, the rate of surroundings airflow and temperature difference between junctions to ambient. The maximum power dissipation can be calculated by following formula: PD(MAX) = ( TJ(MAX) - TA ) / θJA Where TJ(MAX) is the maximum operation junction temperature 125°C, TA is the ambient temperature and the θJA is the junction to ambient thermal resistance. Current Limit Protection When output current at OUT pin is higher than current limit threshold, the current limit protection will be triggered and clamp the output current to approximately 750mA to prevent over-current and to protect the regulator from damage due to overheating. Short circuit protection When VOUT pin is shorted to GND or VOUT voltage is less than 200mV, short circuit protection will be triggered and clamp the output current to approximately 70mA. Vin Vout C Co ESR Iin IN AP7217C GND Iq OUT Iout |
Similar Part No. - AP7217C |
|
Similar Description - AP7217C |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | 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 |