 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
C3216X5R0J476M Datasheet(PDF) 10 Page - National Semiconductor (TI) |
|
|
||||||||||||||||||||||||||||||
C3216X5R0J476M Datasheet(HTML) 10 Page - National Semiconductor (TI) |
|
|
10 / 22 page  A second criteria before finalizing the C in bypass capacitor is the RMS current capability. The necessary RMS current rat- ing of the input capacitor to a buck regulator can be estimated by With this high AC current present in the input capacitor, the RMS current rating becomes an important parameter. The maximum input capacitor ripple voltage and RMS current oc- cur at 50% duty cycle. Select an input capacitor rated for at least the maximum calculated I Cin(RMS). Additional bulk capacitance with higher ESR may be required to damp any resonance effects of the input capacitance and parasitic inductance. Output Capacitor Selection In general, 22 µF to 100 µF high quality dielectric (X5R, X7R) ceramic capacitor rated at twice the maximum output voltage is sufficient given the optimal high frequency characteristics and low ESR of ceramic dielectrics. Although, the output ca- pacitor can also be of electrolytic chemistry for increased capacitance density. Two output capacitance equations are required to determine the minimum output capacitance. One equation determines the output capacitance (C O) based on PWM ripple voltage. The second equation determines C O based on the load tran- sient characteristics. Select the largest capacitance value of the two. The minimum capacitance, given the maximum output volt- age ripple ( ΔV OUT) requirement, is determined by the follow- ing equation: Where the peak to peak inductor current ripple ( Δi L) is equal to: R ESR is the total output capacitor ESR, L is the inductance value of the internal power inductor, where L = 2.2 µH, and f SW = 1 MHz. Therefore, per the design example: The minimum output capacitance requirement due to the PWM ripple voltage is: Three miliohms is a typical R ESR value for ceramic capacitors. The following equation provides a good first pass capacitance requirement for a load transient: Where I step is the peak to peak load step (for this example I step = 10% to 90% of the maximum load), VFB = 0.8V, and ΔV o_tran is the maximum output voltage deviation, which is ±20 mV. Therefore the capacitance requirement for the given design parameters is: In this particular design the output capacitance is determined by the load transient requirements. Table 1 lists some examples of commercially available ca- pacitors that can be used with the LMZ10503. www.national.com 10 |
Similar Part No. - C3216X5R0J476M |
|
Similar Description - C3216X5R0J476M |
|
|
|
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 |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
