ICS854S058AGILF IDT, Integrated Device Technology Inc, ICS854S058AGILF Datasheet - Page 12

• Manufacturer Part Number: ICS854S058AGILF
• Manufacturer: IDT, Integrated Device Technology Inc

Specifications of ICS854S058AGILF

• Lead Free Status / RoHS Status: Compliant

ICS854S058I Datasheet
Power Considerations
This section provides information on power dissipation and junction temperature for the ICS854S058I.
Equations and example calculations are also provided.
1.
The total power dissipation for the ICS854S058I is the sum of the core power plus the power dissipation in the load(s).
The following is the power dissipation for V
NOTE: Please refer to Section 3 for details on calculating power dissipation in the load.
2. Junction Temperature.
Junction temperature, Tj, is the temperature at the junction of the bond wire and bond pad directly affects the reliability of the device. The
maximum recommended junction temperature is 125°C. Limiting the internal transistor junction temperature, Tj, to 125°C ensures that the bond
wire and bond pad temperature remains below 125°C.
In order to calculate junction temperature, the appropriate junction-to-ambient thermal resistance θ
a multi-layer board, the appropriate value is 85.1°C/W per Table 6 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 (multi-layer).
Table 6. Thermal Resistance
ICS854S058AGI REVISION A DECEMBER 11, 2009
Meters per Second
Multi-Layer PCB, JEDEC Standard Test Boards
Power Dissipation.
•
85°C + 0.229W * 85.16°C/W = 104.5°C. This is below the limit of 125°C.
Power (core)
The equation for Tj is as follows: Tj = θ
Tj = Junction Temperature
θ
Pd_total = Total Device Power Dissipation (example calculation is in section 1 above)
T
JA
A
= Ambient Temperature
= Junction-to-Ambient Thermal Resistance
MAX
= V
DD_MAX
θ
JA
* I
for 24 Lead TSSOP, Forced Convection
DD_MAX
DD
= 3.3V + 5% = 3.465V, which gives worst case results.
= 3.465V * 66mA = 228.7mW
JA
* Pd_total + T
θ
JA
A
85.1°C/W
by Velocity
0
12
79.7°C/W
JA
1
8:1, DIFFERENTIAL-TO-LVDS CLOCK MULTIPLEXER
must be used. Assuming no air flow and
©2009 Integrated Device Technology, Inc.
76.5°C/W
2.5