ICS87321AMILF IDT, Integrated Device Technology Inc, ICS87321AMILF Datasheet - Page 12

• Manufacturer Part Number: ICS87321AMILF
• Manufacturer: IDT, Integrated Device Technology Inc
• Type: Clock Dividerr

Specifications of ICS87321AMILF

• Number Of Clock Inputs: 1
• Mode Of Operation: Differential
• Output Logic Level: LVPECL
• Operating Supply Voltage (min): 2.375V
• Operating Supply Voltage (typ): 2.5/3.3V
• Operating Supply Voltage (max): 3.465V
• Package Type: SOIC N
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 8
• Lead Free Status / Rohs Status: Compliant

This section provides information on power dissipation and junction temperature for the ICS87321I.
Equations and example calculations are also provided.
1. Power Dissipation.
The total power dissipation for the ICS87321I 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 dissipation into 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
flow and a multi-layer board, the appropriate value is 95.0°C/W per Table 6 below.
Therefore, Tj for an ambient temperature of 85°C with output 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).
T
IDT
ABLE
ICS87321I
÷1, ÷2 DIFFERENTIAL-TO-3.3V LVPECL CLOCK GENERATOR
™
/ ICS
6. 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 + 0.092W *95°C/W = 93.7°C. This is well below the limit of 125°C.
™
JA
A
3.3V LVPECL CLOCK GENERATOR
= Ambient Temperature
HERMAL
= Junction-to-Ambient Thermal Resistance
R
MAX
ESISTANCE
_MAX
= V
MAX
(3.465V, with outputs switching) = 62.37mW + 30mW = 92.37mW
= 30mW/Loaded Output pair
CC_MAX
* I
JA
EE_MAX
FOR
= 3.465V * 18mA = 62.37mW
8-
PIN
CC
JA
= 3.465V, which gives worst case results.
P
by Velocity (Linear Feet per Minute)
SOIC, F
OWER
JA
* Pd_total + T
ORCED
C
C
ONSIDERATIONS
ONVECTION
A
95.0°C/W
12
0
TM
devices is 125°C.
88.4°C/W
200
JA
ICS87321AMI REV. A APRIL 7, 2009
83.7°C/W
must be used. Assuming no air
500