Electronic Components Datasheet Search |
|
XRP6670EVB Datasheet(PDF) 9 Page - Exar Corporation |
|
XRP6670EVB Datasheet(HTML) 9 Page - Exar Corporation |
9 / 13 page X XR RP P6 66 67 70 0 3 3A A 3 30 00 0k kH Hz z- -2 2..5 5M MH Hz z S Sy yn nc ch hr ro on no ou us s S Stte ep p D Do ow wn n R Re eg gu ulla atto or r © 2013 Exar Corporation 9/13 Rev. 1.0.1 voltages. Note that example inductors shown in tables 3 and 4 are Wurth shielded inductors. VOUT(V) ∆IL(p-p)(A) L(µH) Inductor Example 3.3 0.76 1.5 74437346015 2.8 0.81 1.5 74437346015 2.5 0.84 1.5 74437346015 1.8 0.76 1.5 74437346015 1.5 0.70 1.5 74437346015 1.2 0.62 1.5 74437346015 1.1 0.57 1.5 74437346015 Table 3: Suggested Inductor Values for f=1MHz, VIN=5V and IOUT=2.7A VOUT(V) ∆IL(p-p)(A) L(µH) Inductor Example 2.5 0.41 1.5 74437346015 1.8 0.54 1.5 74437346015 1.5 0.54 1.5 74437346015 1.2 0.51 1.5 74437346015 1.1 0.49 1.5 74437346015 Table 4: Suggested Inductor Values for f=1MHz, VIN=3.3V and IOUT=2.7A OUTPUT CAPACITOR COUT Select the output capacitor for voltage rating, capacitance COUT and Equivalent Series Resistance ESR. The voltage rating, as a rule of thumb, should be at least twice the output voltage. When calculating the required capacitance, usually the overriding requirement is current load-step transient. If the unloading transient (i.e., when load transitions from a high to a low current) is met, then usually the loading transient (when load transitions from a low to a high current) is met as well. Therefore calculate the COUT based on the unloading transient requirement from: ' ( ")*+,- "#./- 0 1234%*541 - -6 Where: L is the inductance calculated in the preceding step IHigh is the value of load-step prior to unloading. This is nominally set equal to regulator current rating (3A). ILow is the value of load-step after unloading. This is nominally set equal to 50% of regulator current rating (1.5A). Vtransient is the maximum permissible voltage transient corresponding to the load step mentioned above. Vtransient is typically specified from 3% to 5% of VOUT. ESR of the capacitor has to be selected such that the output voltage ripple requirement ∆VOUT, nominally 1% of VOUT, is met. Voltage ripple ∆VOUT is mainly composed of two components: the resistive ripple due to ESR and capacitive ripple due to COUT charge transfer. For applications requiring low voltage ripple, ceramic capacitors are recommended because of their low ESR which is typically in the range of 5mΩ. Therefore ∆VOUT is mainly capacitive. For ceramic capacitors calculate the ∆VOUT from: ! !"# 8 ' $% Where: ∆IL is from table 2 or 3 COUT is the value calculated above fs is nominal switching frequency If tantalum or electrolytic capacitors are used then ∆VOUT is essentially a function of ESR: ! !"# 78 INPUT CAPACITOR CIN Select the input capacitor for voltage rating, RMS current rating and capacitance. The voltage rating should be at least 50% higher than the regulator’s maximum input voltage. Calculate the capacitor’s current rating from: "9 ,;<= " >? 1 ? Where: IOUT is regulator’s maximum current (3A) D is duty cycle (D=VOUT/VIN) Calculate the CIN capacitance from: ' " $% - ! |
Similar Part No. - XRP6670EVB |
|
Similar Description - XRP6670EVB |
|
|
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 |