isl59911 Intersil Corporation, isl59911 Datasheet - Page 12

• Manufacturer Part Number: isl59911
• Description: 250mhz Triple Differential Receiver/ Equalizer With I 2c Interface
• Manufacturer: Intersil Corporation

Power Dissipation
The ISL59911 is designed to operate with ±5V supply voltages.
The supply currents are tested in production and guaranteed to
be less than 140mA per channel. Operating at ±5V power supply,
the total power dissipation is shown by Equation 1:
Where:
• PD
• V
• I
• V
• The 3 term comes from the number of channels
• R
• PD
θ
This is done using Equation 2:
Where:
T
T
For a 32 Ld QFN package in a proper layout PCB heatsinking
copper area, 31°C/W θ
disperse the heat, the bottom heatspreader must be soldered to
the PCB. Heat flows through the heatspreader to the circuit board
copper, then spreads and converts to air. Thus the PCB copper
plane becomes the heatsink. This has proven to be a very
effective technique. A separate application note that details the
32 pin QFN PCB design considerations is available.
PD
θ
J
A
JA
JA
application = 2V
is the maximum junction temperature (+150°C)
is the maximum ambient temperature (+85°C)
MAX
MAX
S
OUTMAX
L
required for long term reliable operation can be calculated.
=
MAX
= Supply voltage = 5V
MAX
= Load resistance = 150Ω
(
T
= Maximum quiescent supply current = 140mA
=
J
–
= Maximum power dissipation
= 1.4W
2
T
= Maximum output voltage swing of the
A
×
) PD
V
⁄
S
×
I
=
SMAX
(
46°C
JA
+
thermal resistance can be achieved. To
3 V
) W
(
⁄
S
12
- V
OUTMAX
)
×
V
------------------------
OUTMAX
R
L
ISL59911
(EQ. 1)
(EQ. 2)
September 2, 2011
FN7548.0