PCS5I961P Datasheet, PDF (9/14 Pages) PulseCore Semiconductor – Low Voltage Zero Delay Buffer

November 2006
PCS5I961P
rev 0.3
∑ ^PTOT

= _I _CCQ

+ V_CC
⋅
f _CLOCK
⋅


N
⋅
C _PD
+
M
C
L


⋅
V_CC
Equation1
∑ ∑^{[ ( ) ] ( ) P}TOT
= V_CC

⋅ _I _CCQ

+ V_CC
⋅
f _CLOCK
⋅  N

⋅ C _PD
+
M
C_L  +
P
DC_Q ⋅ I _OH V_CC − V_OH
+ 1 − DC_Q ⋅ I _OL ⋅V_OL
Equation 2
T_J = T_A + P_TOT ⋅ R_thja
Equation 3
( ) f _CLOCKMAX
=
C _PD
1
⋅ N ⋅ V_C²_C
⋅ _^{TJMAX − TA}
 ^Rthja
−
I _CCQ ⋅ V_CC



Equation 4
Where R_thja is the thermal impedance of the package
(junction to ambient) and T_A is the ambient temperature.
According to Table 9, the junction temperature can be
used to estimate the long-term device reliability. Further,
combining equation 1 and equation 2 results in a
maximum operating frequency for the PCS5I961P in a
series terminated transmission line system.
Table 10: Thermal package impedance of the 32LQFP
Convection, LFPM
Still air
100 lfpm
200 lfpm
300 lfpm
400 lfpm
500 lfpm
R_thja (1P2S board), K/W
80
70
61
57
56
55
T_J,MAX should be selected according to the MTBF system
requirements and Table 9. R_thja can be derived from
Table 10. The R_thja represent data based on 1S2P
boards, using 2S2P boards will result in a lower thermal
impedance than indicated below. If the calculated
maximum frequency is below 200 MHz, it becomes the
upper clock speed limit for the given application
conditions. The following two derating charts describe the
safe frequency operation range for the PCS5I961P. The
charts were calculated for a maximum tolerable die
junction temperature of 110°C, corresponding to an
estimated MTBF of 9.1 years, a supply voltage of 3.3V
and series terminated transmission line or capacitive
loading. Depending on a given set of these operating
conditions and the available device convection a decision
on the maximum operating frequency can be made.
There are no operating frequency limitations if a 2.5V
power supply or the system specifications allow for a
MTBF of 4 years (corresponding to a max. junction
temperature of 120°C.
Low Voltage Zero Delay Buffer
Notice: The information in this document is subject to change without notice.
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