Electronic Components Datasheet Search |
|
EL6208CW Datasheet(PDF) 9 Page - Intersil Corporation |
|
EL6208CW Datasheet(HTML) 9 Page - Intersil Corporation |
9 / 11 page 9 7374.1 August 10, 2007 noise on the power lines is common. There needs to be a lossy bead inductance and secondary bypass on the supply side to control signals from propagating down the wires. Figure 20 shows the typical connection. FIGURE 20. RECOMMENDED SUPPLY BYPASSING Also important is circuit-board layout. At the EL6208's operating frequencies, even the ground plane is not low-impedance. High frequency current will create voltage drops in the ground plane. Figure 21 shows the output current loops. FIGURE 21. OUTPUT CURRENT LOOPS For the pushing current loop, the current flows through the bypass capacitor, into the EL6208 supply pin, out the IOUT pin to the laser, and from the laser back to the decoupling capacitor. This loop should be small. For the pulling current loop, the current flows into the IOUT pin, out of the ground pin, to the laser cathode, and from the laser diode back to the IOUT pin. This loop should also be small. Power Dissipation With the high output drive capability, the EL6208 is possible to exceed the +125°C “absolute-maximum junction temperature” under certain conditions. Therefore, it is important to calculate the maximum junction temperature for the application to determine if the conditions need to be modified for the oscillator to remain in the safe operating area. The maximum power dissipation allowed in a package is determined according to Equation 1: where: PDMAX = Maximum power dissipation in the package TJMAX = Maximum junction temperature TAMAX = Maximum ambient temperature θJA = Thermal resistance of the package The supply current of the EL6208 depends on the peak-to- peak output current and the operating frequency which are determined by resistors RAMP and RFREQ. The supply current can be predicted approximately by Equation 2: The power dissipation can be calculated from Equation 3: Here, VSUP is the supply voltage. Figures 22 and provide a convenient way to see if the device will overheat. The maximum safe power dissipation can be found graphically, based on the package type and the ambient temperature. By using the previous equation, it is a simple matter to see if PD exceeds the device's power derating curve. To ensure proper operation, it is important to observe the recommended derating curve shown in Figures 22 and . A flex circuit may have a higher θJA, and lower power dissipation would then be required. FIGURE 22. PACKAGE POWER DISSIPATION vs AMBIENT TEMPERATURE +5V VS L SERIES: 70 Ω REACTANCE AT 300MHz 0.1µF CHIP EL6208 GND 0.1µF CHIP SINKING CURRENT LOOP SOURCING CURRENT LOOP SUPPLY BYPASS LASER DIODE RFREQ RAMP GND P DMAX T JMAX - TAMAX Θ JA --------------------------------------------- = (EQ. 1) I SUP 31.25mA 1k Ω × R AMP ------------------------------------------- 30mA 1k Ω × R FREQ ---------------------------------- 0.6mA ++ = (EQ. 2) P D V SUP I SUP × = (EQ. 3) 0.6 0.5 0.4 0.3 0.2 0.1 0 0 25 50 75 100 125 150 AMBIENT TEMPERATURE (°C) 85 JEDEC JESD51-3 LOW EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD 488mW 6 Ld SO T-2 3 θ JA = +2 56 C/W EL6208 |
Similar Part No. - EL6208CW |
|
Similar Description - EL6208CW |
|
|
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 |