ICS85454AKT IDT, Integrated Device Technology Inc, ICS85454AKT Datasheet - Page 10

• Manufacturer Part Number: ICS85454AKT
• Manufacturer: IDT, Integrated Device Technology Inc

Specifications of ICS85454AKT

• Function: Clock Multiplexer
• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Package Type: VFQFN
• Pin Count: 16
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Not Compliant

T
IDT
This section provides information on power dissipation and junction temperature for the ICS85454.
Equations and example calculations are also provided.
1. Power Dissipation.
The total power dissipation for the ICS85454 is the sum of the core power plus the power dissipated in the load(s).
The following is the power dissipation for V
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 θ
no air flow and a multi-layer board, the appropriate value is 51.5°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 (single layer or multi-layer).
ABLE
ICS85454
DUAL 2:1 AND 1:2 DIFFERENTIAL-TO-LVDS MULTIPLEXER
™
•
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
85°C + 0.247W * 51.5°C/W = 97.7°C. This is well below the limit of 125°C.
/ ICS
JA
A
Multi-Layer PCB, JEDEC Standard Test Boards
6. T
= Ambient Temperature
= Junction-to-Ambient Thermal Resistance
Power_
™
DUAL 2:1 AND 1:2 LVDS MULTIPLEXER
HERMAL
MAX
= V
R
ESISTANCE
DD_MAX
* I
DD_MAX
θ θ θ θ θ
= 2.625V * 94mA = 247mW
JA
θ θ θ θ θ
JA
FOR
vs. 0 Air Flow (Linear Feet per Minute)
P
16-P
DD
OWER
JA
= 2.5V + 5% = 2.625V, which gives worst case results.
* Pd_total + T
IN
VFQFN, F
C
ONSIDERATIONS
A
ORCED
51.5°C/W
10
C
0
ONVECTION
TM
devices is 125°C.
ICS85454 REV. B FEBRUARY 24, 2009
JA
must be used. Assuming