ICS85354AK-01LFT IDT, Integrated Device Technology Inc, ICS85354AK-01LFT Datasheet - Page 14

• Manufacturer Part Number: ICS85354AK-01LFT
• Description: IC MUX DUAL 2:1 1:2 16-VFQFPN
• Manufacturer: IDT, Integrated Device Technology Inc
• Series: HiPerClockS™r
• Type: Multiplexerr

Specifications of ICS85354AK-01LFT

• Number Of Circuits: 2
• Ratio - Input:output: 2:1, 1:2
• Differential - Input:output: Yes/Yes
• Input: CML, LVDS, LVPECL
• Output: LVPECL
• Frequency - Max: 2.5GHz
• Voltage - Supply: 2.375 V ~ 3.465 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-VFQFN
• Frequency-max: 2.5GHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 85354AK-01LFT

This section provides information on power dissipation and junction temperature for the ICS85354-01.
Equations and example calculations are also provided.
1. Power Dissipation.
The total power dissipation for the ICS85354-01 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
Assuming 0 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).
T
85354AK-01
ABLE
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 + 0.231W * 51.5°C/W = 96.9°C. This is well below the limit of 125°C.
JA
A
6. T
Multi-Layer PCB, JEDEC Standard Test Boards
= Ambient Temperature
= Junction-to-Ambient Thermal Resistance
Power (core)
Power (outputs)
If all outputs are loaded, the total power is 3 * 30.92mW = 92.76mW
Total Power
HERMAL
R
ESISTANCE
MAX
_MAX
MAX
= V
(3.465, with all outputs switching) = 138.6mW + 92.76mW = 231.4mW
= 30.92mW/Loaded Output pair
CC_MAX
JA
FOR
* I
EE_MAX
JA
16-
vs. 0 Air Flow (Linear Feet per Minute)
P
PIN
CC
= 3.465V * 40mA = 138.6mW
JA
PRELIMINARY
OWER
* Pd_total + T
VFQFN, F
= 3.465V, which gives worst case results.
C
ORCED
ONSIDERATIONS
A
D
14
C
IFFERENTIAL
ONVECTION
51.5°C/W
0
TM
-
TO
devices is 125°C.
-LVPECL/ECL M
ICS85354-01
JA
must be used.
D
REV. A JANUARY 16, 2008
UAL
ULTIPLEXER
2:1/1:2