8T49N287 Datasheet, PDF (68/75 Pages) Integrated Circuit Systems – Optional Fast Lock function

8T49N287 DATA SHEET
Example 2. High-Frequency Customer Configuration (3.3V Core Voltage)
Output
Q0
Q1
Q2
Q3
Q4
Q5
Q6
Q7
PLL0
PLL1
Output Type
LVDS
LVDS
LVPECL
LVPECL
HCSL
HCSL
HCSL
HCSL
Frequency (MHz)
625.00
625.00
161.133
161.133
25
25
125
156.25
Enabled
Disabled
V_CCO
2.5
2.5
2.5
2.5
3.3
3.3
3.3
3.3
• Core Supply Current, I_CC = 100mA (max)
• Analog Supply Current, I_CCA = 187mA (max, PLL0 path only)
Q0 Current = 0.00366x625 + 40.8 = 43.09mA
Q1 Current = 0.00366x625 + 40.8 = 43.09mA
Q2 Current = 0.01134x161.133 + 56.5 = 58.3mA
Q3 Current = 0.01134x161.133 + 56.5 = 58.3mA
Q4 Current = 0.00553x25 + 43.1 = 43.24mA
Q5 Current = 0.00553x25 + 43.1 = 43.24mA
Q6 Current = 0.00553x125 + 43.1 = 43.79mA
Q7 Current = 0.00553x156.25 + 43.1 = 43.96mA
• Total Output Current = 202.8mA (V_CCO = 2.5V), 174.23mA (V_CCO = 3.3V)
Total Device Power = 3.465V *(100mA + 187mA + 174.23mA) + 2.625V * 202.8mA = 2130.5mW
• Power dissipated through output loading:
LVPECL = 27.95mW * 2 = 55.9mW
LVDS = already accounted for in device power
HCSL = 44.5mW * 4 = 178mW
LVCMOS = n/a
Total Power = 2130.5mW + 55.9mW + 178mW = 2364.4mW or 2.36W
With an ambient temperature of 85°C, the junction temperature is:
T_J = 85°C + 16.1°C/W *2.36W = 123°C
This junction temperature is below the maximum allowable.
FEMTOCLOCK^® NG OCTAL UNIVERSAL FREQUENCY TRANSLATOR
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REVISION 5 07/09/15