Electronic Components Datasheet Search |
|
EN1M12 Datasheet(PDF) 10 Page - Vicor Corporation |
|
EN1M12 Datasheet(HTML) 10 Page - Vicor Corporation |
10 / 12 page Vicor Corp. Tel: 800-735-6200, 978-470-2900 Fax: 978-475-6715 ENMods System: FARM3 and MiniHAM Rev. 1.3 Page 10 of 12 Set your site on VICOR at www.vicorpower.com PRELIMINARY Calculated values of bus capacitance for various hold-up time, ride-through time, and ripple voltage requirements are given as a function of operating power level in Figures 14, 15, and 16, respectively. Example In this example, the output required from the DC-DC converter at the point of load is 12Vdc at 320W. Therefore, the output power from the ENMods would be 375W (assuming a converter efficiency of 85%). The desired hold-up time is 9ms over an input range of 90 to 264Vac. Determining Required Capacitance for Power Fail Warning. Figure 14 is used to determine capacitance for a given power fail warning time and power level, and shows that the total bus capacitance should be at least 820µF. Since two capacitors are used in series, each capacitor should be at least 1,640µF. Note that warning time is not dependent on line voltage. A hold-up capacitor calculator is available on the Vicor website, at vicorpower.com. Determining Ride-through Time. Figure 15 illustrates ride- through time as a function of line voltage and output power, and shows that at a nominal line of 90Vac, ride-through would be 68ms. Ride-through time is a function of line voltage. Determining Ripple Voltage on the Hold-up Capacitors. Figure 16 is used to determine ripple voltage as a function of operating power and bus capacitance, and shows that the ripple voltage across the hold-up capacitors will be 12V p-p. Determining the Ripple on the Output of the DC-DC Converter. Figure 17 is used to determine the ripple rejection of the DC-DC converter and indicates a ripple rejection of approximately 60 dB for a 12V output. Since the ripple on the bus voltage is 12Vac and the ripple rejection of the converter is 60 dB, the output ripple of the converter due to ripple on its input (primarily 120 Hz) will be 12mV p-p. Note that 2nd Generation converters have greater ripple rejection then either VI-200s or VI-J00s. A variety of hold-up capacitor assemblies (HUBs) are available. Please visit the Vicor website @ vicorpower.com. For more information about designing an autoranging AC input power supply using the ENMods and Vicor DC-DC converter modules, contact Vicor Applications Engineering at the nearest Vicor Technical Support Center, or send E-mail to apps@vicorpower.com. • • • The power fail warning time ( ∆t) is defined as the interval between BOK and converter shutdown (EN) as illustrated in Figure 13. The Bus-OK and Enable thresholds are 205V and 185V, respectively. A simplified relationship between hold-up time, operating power, and bus capacitance is obtained by inserting these constants in equation (3): C = 2P ∆t / (2052 – 1852) C = 2P ∆t / (7,800) It should be noted that the series combination (C1, C2, see Figure 1a) requires each capacitor to be twice the calculated value, but the required voltage rating of each capacitor is reduced to 200V. Allowable ripple voltage on the bus (or ripple current in the capacitors) may define the capacitance requirement. Consideration should be given to converter ripple rejection and resulting output ripple voltage. The ripple rejection (R) of Vicor converters is specified as a function of the input/output voltage ratio: R = 30 + 20log(Vin / Vout) (4) For example, a converter whose output is 15V and nominal input is 300V will provide 56dB ripple rejection, i.e., 10V p-p of input ripple will produce 15mV p-p of output ripple (see Figure 17). Equation 3 is again used to determine the required capacitance. In this case, V1 and V2 are the instantaneous values of bus voltage at the peaks and valleys (see Figure 13) of the ripple, respectively. The capacitors must holdup the bus voltage for the time interval ( ∆t) between peaks of the rectified line as given by: ∆t = (π – θ) / 2πf (5) Where: f = line frequency θ = rectifier conduction angle The approximate conduction angle is given by: θ = Cos-1 (V 2/V1) (6) Another consideration in hold-up capacitor selection is their ripple current rating. The capacitors’ rating must be higher than the maximum operating ripple current. The approximate operating ripple current (rms) is given by: I rms = 2P/Vac (7) Where: P = total output power Vac = operating line voltage Application Note (continued) |
Similar Part No. - EN1M12 |
|
Similar Description - EN1M12 |
|
|
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 |