ICS8536I-33 Datasheet, PDF (13/19 Pages) Integrated Device Technology – LOW SKEW, 1-TO-6, CRYSTAL OSCILLATOR/LVCMOSTO-3.3V, 2.5V LVPECL/LVCMOS FANOUT BUFFER

ICS8536I-33
LOW SKEW, 1-TO-6, CRYSTAL OSCILLATOR/LVCMOS-TO-3.3V, 2.5V LVPECL/LVCMOS FANOUT BUFFER
POWER CONSIDERATIONS
This section provides information on power dissipation and junction temperature for the ICS8536I-33.
Equations and example calculations are also provided.
1. Power Dissipation.
The total power dissipation for the ICS8536I-33 is the sum of the core power plus the power dissipated in the load(s).
The following is the power dissipation for V = 3.3V + 5% = 3.465V, which gives worst case results.
CC
NOTE: Please refer to Section 3 for details on calculating power dissipated in the load.
Core and LVPECL Output Power Dissipation
• Power (core) = V * I = 3.465V * 80mA = 277.2mW
MAX
CC_MAX
EE_MAX
• Power (outputs) = 30mW/Loaded Output pair
MAX
If all outputs are loaded, the total power is 3 * 30mW = 90mW
LVCMOS Output Power Dissipation
• Output Impedance R Power Dissipation due to Loading 50Ω to V
/2
OUT
CCO_LVCMOS
Output Current I_OUT = V_{CCO_MAX} / [2 * (50Ω + R_OUT)] = 3.465V / [2 * (50Ω + 15Ω] = 26.7mA
• Power Dissipation on the R_OUT per LVCMOS output
Power (R_OUT) = R_OUT * (I_OUT)² = 15Ω * (26.7mA)² = 10.7mW per output
• Total Power Dissipation on the R_OUT
Total Power (R_OUT) = 10.7mW * 3 = 32.1mW
Total Power Dissipation
• Total Power
= Power (LVPECL) + Total Power (R )
OUT
= 277.2mW + 90mW + 32.1mW
= 399.3mW
IDT^™ / ICS^™ 3.3V, 2.5V LVPECL/ LVCMOS FANOUT BUFFER
13
ICS8536CGI-33 REV. B OCTOBER 27, 2008