ics8536-01 Integrated Device Technology, ics8536-01 Datasheet - Page 14

• Manufacturer Part Number: ics8536-01
• Description: Xtal, Lvcmos, Differential Input Lvpecl Output 1 6 266-mhz Buffer
• Manufacturer: Integrated Device Technology

This section provides information on power dissipation and junction temperature for the ICS8536-01.
Equations and example calculations are also provided.
1. Power Dissipation.
The total power dissipation for the ICS8536-01 is the sum of the core power plus the power dissipated in the load(s).
The following is the power dissipation for V
NOTE: Please refer to Section 3 for details on calculating power dissipated in the load.
2. Junction Temperature.
Junction temperature, Tj, is the temperature at the junction of the bond wire and bond pad and directly affects the reliability of the
device. The maximum recommended junction temperature for HiPerClockS
In order to calculate junction temperature, the appropriate junction-to-ambient thermal resistance
moderate air flow of 1 meter per second and a multi-layer board, the appropriate value is 65°C/W per Table 7 below.
Therefore, Tj for an ambient temperature of 70°C with all outputs switching is:
This calculation is only an example. Tj will obviously vary depending on the number of loaded outputs, supply voltage, air flow,
and the type of board (single layer or multi-layer).
T
IDT
ABLE
ICS8536-01
LOW SKEW, 1-TO-6, CRYSTAL/LVCMOS/DIFFERENTIAL-TO-3.3V, 2.5V LVPECL FANOUT BUFFER
™
/ ICS
7. T
Multi-Layer PCB, JEDEC Standard Test Boards
Power (core)
Power (outputs)
If all outputs are loaded, the total power is 6 * 30mW = 180mW
Total Power
The equation for Tj is as follows: Tj =
Tj = Junction Temperature
Pd_total = Total Device Power Dissipation (example calculation is in section 1 above)
T
70°C + 0.423W * 65°C/W = 97.5°C. This is well below the limit of 125°C.
™
JA
A
3.3V, 2.5V LVPECL FANOUT BUFFER
= Ambient Temperature
HERMAL
= Junction-to-Ambient Thermal Resistance
R
MAX
ESISTANCE
_MAX
= V
MAX
(3.465V, with all outputs switching) = 242.55mW + 180mW = 422.6mW
= 30mW/Loaded Output pair
CC_MAX
* I
JA
EE_MAX
FOR
= 3.465V * 70mA = 242.55mW
24-
CC
PIN
= 3.3V + 5% = 3.465V, which gives worst case results.
P
JA
TSSOP, F
by Velocity (Meters per Second)
OWER
JA
* Pd_total + T
ORCED
C
ONSIDERATIONS
A
C
14
ONVECTION
70°C/W
0
TM
devices is 125°C.
65°C/W
1
ICS8536AG-01 REV. B NOVEMBER 3, 2006
JA
must be used. Assuming a
62°C/W
2.5
PRELIMINARY