8T49N242 Datasheet, PDF (58/65 Pages) Integrated Circuit Systems – Open-drain Interrupt pin

8T49N242 DATA SHEET
Example 2. Common Customer Configuration (2.5V Core Voltage)
Output
Q0
Q1
Q2
Q3
Output Type
LVPECL
LVDS
HCSL
LVCMOS
Frequency (MHz)
156.25
125
125
25
V_CCO
2.5
2.5
2.5
2.5
• Core Supply Current + Control and Status Supply Current = I_CC + I_CCCS = 52mA (max)
• Analog Supply Current, I_CCA = 116mA (max)
• Output Supply Current:
Q0 Current = 156.25 * 0.00476 + 28.1 = 28.84mA
Q1 Current = 125 * 0.00496 + 36.3 = 36.92mA
Q2 Current = 125 * 0.00448 + 28.2= 28.76mA
Q3 Current = 26.2mA
• Total Output Supply Current = 120.72mA (max)
• Total Device Current = 52mA + 116mA + 120.72mA = 288.72mA
• Total Device Power = 2.625V * 288.72mA = 757.89mW
• Power dissipated through output loading:
LVPECL = 27.95mW * 1 = 27.95mW
LVDS = already accounted for in device power
HCSL = 45.5mW * 1 = 44.5mW
LVCMOS = 10.5pF * 25MHz * (2.625V)² * 1 output pair = 1.81mW
• Total Power = 757.89mW + 27.95mW + 44.5mW + 1.81mW = 832.15mW or 0.832W
With an ambient temperature of 85°C and no airflow, the junction temperature is:
T_J = 85°C + 26.3°C/W * 0.832W = 106.9°C
This is below the limit of 125°C.
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REVISION 2 08/07/15