GA100358SCILF Integrated Circuit Systems, Inc., GA100358SCILF Datasheet - Page 12

• Manufacturer Part Number: GA100358SCILF
• Description: IC FANOUT BUFFER SINGLE 8TSSOP TUBE
• Manufacturer: Integrated Circuit Systems, Inc.

This section provides information on power dissipation and junction temperature for the ICS853001.
Equations and example calculations are also provided.
1. Power Dissipation.
The total power dissipation for the ICS853001 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 90.5°C/W per Table 5A below.
Therefore, Tj for an ambient temperature of 85°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
T
853001AG
ABLE
ABLE
Single-Layer PCB, JEDEC Standard Test Boards
Multi-Layer PCB, JEDEC Standard Test Boards
NOTE: Most modern PCB designs use multi-layered boards. The data in the second row pertains to most designs.
5A. T
5B. T
Multi-Layer PCB, JEDEC Standard Test Boards
Power (core)
Power (outputs)
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
85°C + 0.170W * 90.5°C/W = 100.4°C. This is well below the limit of 125°C.
JA
A
= Ambient Temperature
= junction-to-ambient thermal resistance
HERMAL
HERMAL
Integrated
Circuit
Systems, Inc.
R
R
MAX
_MAX
ESISTANCE
ESISTANCE
MAX
= V
= 27.83mW/Loaded Output pair
(3.465V) = 141.75mW + 27.83mW = 169.58mW
CC_MAX
* I
JA
JA
CC_MAX
FOR
FOR
JA
P
8-P
CC
8-P
JA
by Velocity (Linear Feet per Minute)
= 5.25V * 27mA = 141.75mW
= 5V + 5% = 5.25V, which gives worst case results.
www.icst.com/products/hiperclocks.html
OWER
by Velocity (Meters per Second)
IN
IN
JA
TSSOP, F
SOIC, F
* Pd_total + T
C
ORCED
ONSIDERATIONS
ORCED
A
12
C
153.3°C/W
112.7°C/W
101.7°C/W
ONVECTION
C
ONVECTION
2.5V, 3.3V, 5V LVPECL/ECL B
0
0
TM
devices is 125°C.
1:1, D
128.5°C/W
103.3°C/W
90.5°C/W
200
1
IFFERENTIAL
JA
must be used. Assuming a
115.5°C/W
ICS853001
97.1°C/W
89.8°C/W
500
2
LVPECL-
REV. A JANUARY 29, 2005
UFFER
TO
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