Electronic Components Datasheet Search |
|
IRU1260CT Datasheet(PDF) 5 Page - International Rectifier |
|
IRU1260CT Datasheet(HTML) 5 Page - International Rectifier |
5 / 10 page IRU1260 5 Rev. 2.1 09/19/02 www.irf.com Stability The IRU1260 requires the use of an output capacitor as part of the frequency compensation in order to make the regulator stable. Typical designs for the microprocessor applications use standard electrolytic capacitors with typical ESR in the range of 50 to 100m V and the output capacitance of 500 to 1000 mF. Fortunately as the ca- pacitance increases, the ESR decreases resulting in a fixed RC time constant. The IRU1260 takes advantage of this phenomena in making the overall regulator loop stable. For most applications a minimum of 100 mF alu- minum electrolytic capacitor with the maximum ESR of 0.3 V such as Sanyo, MVGX series, Panasonic FA se- ries as well as the Nichicon PL series insures both sta- bility and good transient response. The IRU1260 also requires a 1 mF ceramic capacitor connected from VIN to VCTRL and a 10 V, 0.1W resistor in series with VCTRL pin in order to further insure stability. Thermal Design The IRU1260 incorporates an internal thermal shutdown that protects the device when the junction temperature exceeds the maximum allowable junction temperature. Although this device can operate with junction tempera- tures in the range of 150 8C, it is recommended that the selected heat sink be chosen such that during maxi- mum continuous load operation the junction tempera- ture is kept below this number. The example given shows the steps in selecting the proper regulator heat sink for driving the Pentium IITM processor GTL+ termination resistors and the Clock IC using the IRU1260 TO-263 package. Example: Assuming the following specifications: The steps for selecting a proper heat sink to keep the junction temperature below 135 8C is given as: 1) Calculate the maximum power dissipation using: 2) Assuming a TO-263 surface mount package, the junc- tion to ambient thermal resistance of the package is: 3) The maximum junction temperature of the device is calculated using the equation below: Since this is lower than our selected 135 8C maxi- mum junction temperature (150 8C is the thermal shut- down of the device), TO-263 package is a suitable package for our application. VIN = 3.3V VOUT1 = 2.5V VOUT2 = 1.5V IOUT1(MAX) = 0.2A IOUT2(MAX) = 1.5A TA = 35 8C PD = IOUT1 3(VIN - VOUT1) + IOUT23(VIN - VOUT2) PD = 0.2 3(3.3 - 2.5) + 1.53(3.3 - 1.5) = 2.86W uJA = 308C/W for 1" square pad area TJ = TA + PD 3uJA TJ = 35 + 2.86 330 = 1218C |
Similar Part No. - IRU1260CT |
|
Similar Description - IRU1260CT |
|
|
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 |