874005AG-04LF Integrated Device Technology (Idt), 874005AG-04LF Datasheet - Page 10

• Manufacturer Part Number: 874005AG-04LF
• Description: PCI Express Jitter Attenuator 24-Pin TSSOP Tube
• Manufacturer: Integrated Device Technology (Idt)

Specifications of 874005AG-04LF

• Package: 24TSSOP
• Operating Temperature: 0 to 70 °C

T
IDT
This section provides information on power dissipation and junction temperature for the ICS874005-04.
Equations and example calculations are also provided.
1. Power Dissipation (typical).
The total power dissipation for the ICS874005-04 is the sum of the core power plus the analog power plus the power dissipated in
the load(s). The following is the power dissipation for V
2. Junction Temperature (typical).
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 82.3°C/W per Table 6 below.
Therefore, Tj for an ambient temperature of 70°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.
ABLE
ICS874005-04
PCI EXPRESS™ JITTER ATTENUATOR
™
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
70°C + 0.572W * 82.3°C/W = 117.1°C. This is below the limit of 125°C.
/ ICS
JA
A
6. T
= Ambient Temperature
= Junction-to-Ambient Thermal Resistance
Power (core)
Power (outputs)
Total Power
™
Multi-Layer PCB, JEDEC Standard Test Boards
PCI EXPRESS™ JITTER ATTENUATOR
HERMAL
R
MAX
ESISTANCE
_MAX
= V
MAX
= 311.85mW + 259.875mW = 571.725mW
= V
DD_MAX
DDO_MAX
* (I
JA
FOR
DD_MAX
* I
DDO_MAX
24-L
+ I
DDA_MAX
JA
= 3.465V * 75mA = 259.875mW
P
EAD
JA
* Pd_total + T
by Velocity (Meters per Second)
OWER
) = 3.465V * (80mA + 10mA) = 311.85mW
TSSOP, F
DD
= 3.3V + 5% = 3.465V, which gives worst case results.
C
A
ORCED
ONSIDERATIONS
10
C
82.3°C/W
ONVECTION
0
TM
devices is 125°C.
78.0°C/W
1
ICS874005AG-04 REV. A JULY 29, 2008
JA
must be used. Assuming no air
75.9°C/W
2.5