ICS85304AG-01LF IDT, Integrated Device Technology Inc, ICS85304AG-01LF Datasheet - Page 10
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ICS85304AG-01LF
Manufacturer Part Number
ICS85304AG-01LF
Description
IC FANOUT BUFFER 1-5 20-TSSOP
Manufacturer
IDT, Integrated Device Technology Inc
Series
HiPerClockS™r
Type
Fanout Buffer (Distribution), Multiplexerr
Datasheet
1.ICS85304AG-01LFT.pdf
(15 pages)
Specifications of ICS85304AG-01LF
Number Of Circuits
1
Ratio - Input:output
2:5
Differential - Input:output
Yes/Yes
Input
HCSL, LVDS, LVHSTL, LVPECL, SSTL
Output
LVPECL
Frequency - Max
650MHz
Voltage - Supply
3.135 V ~ 3.465 V
Operating Temperature
0°C ~ 70°C
Mounting Type
Surface Mount
Package / Case
20-TSSOP
Frequency-max
650MHz
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
85304AG-01LF
Power Considerations
This section provides information on power dissipation and junction temperature for the ICS85304-01.
Equations and example calculations are also provided.
1.
The total power dissipation for the ICS85304-01 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.
Total Power_
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 devices is 125°C.
In order to calculate junction temperature, the appropriate junction-to-ambient thermal resistance θ
and a multi-layer board, the appropriate value is 73.2°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).
Table 6. Thermal Resistance
IDT™ / ICS™ 3.3V LVPECL FANOUT BUFFER
Linear Feet per Minute
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.
ICS85304-01
LOW SKEW, 1-TO-5 DIFFERENTIAL-TO- 3.3V LVPECL FANOUT BUFFER
Power Dissipation.
•
•
Power (core)
Power (outputs)
If all outputs are loaded, the total power is 5 * 30.2mW = 151mW
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
70°C + 0.342W * 73.2°C/W = 95°C. This is well below the limit of 125°C.
JA
A
= Ambient Temperature
= Junction-to-Ambient Thermal Resistance
MAX
(3.465V, with all outputs switching) = 190.57mW + 151mW = 341.57mW
MAX
MAX
= V
= 30.2mW/Loaded Output pair
CC_MAX
θ
JA
* I
for 20 Lead TSSOP, Forced Convection
EE_MAX
CC
= 3.3V + 5% = 3.465V, which gives worst case results.
JA
= 3.465V * 55mA = 190.57mW
* Pd_total + T
θ
JA
114.5°C/W
73.2°C/W
A
by Velocity
0
10
98.0°C/W
66.6°C/W
200
JA
must be used. Assuming no air flow
ICS85304AG-01 REV. E JULY 8, 2008
88.0°C/W
63.5°C/W
500