el5174 Intersil Corporation, el5174 Datasheet - Page 12

• Manufacturer Part Number: el5174
• Description: 550mhz Differential Twisted-pair Drivers
• Manufacturer: Intersil Corporation

Where:
The maximum power dissipation actually produced by an IC
is the total quiescent supply current times the total power
supply voltage, plus the power in the IC due to the load, or:
Where:
By setting the two PD
can solve the output current and R
overheat.
PD
T
T
θ
V
I
ΔV
application
R
I
i = Number of channels
SMAX
LOAD
AMAX
JA
JMAX
S
LD
=
O
= Total supply voltage
i
= Thermal resistance of the package
= Differential load resistance
×
= Maximum differential output voltage of the
⎛
⎜
⎝
= Load current
= Maximum quiescent supply current per channel
= Maximum junction temperature
V
= Maximum ambient temperature
S
×
I
SMAX
+
MAX
V
S
×
equations equal to each other, we
ΔV
----------- -
R
12
LD
O
⎞
⎟
⎠
LD
to avoid the device
EL5174, EL5374
Power Supply Bypassing and Printed Circuit
Board Layout
As with any high frequency device, a good printed circuit
board layout is necessary for optimum performance. Lead
lengths should be as sort as possible. The power supply pin
must be well bypassed to reduce the risk of oscillation. For
normal single supply operation, where the V
connected to the ground plane, a single 4.7µF tantalum
capacitor in parallel with a 0.1µF ceramic capacitor from V
to GND will suffice. This same capacitor combination should
be placed at each supply pin to ground if split supplies are to
be used. In this case, the V
supply rail.
For good AC performance, parasitic capacitance should be
kept to minimum. Use of wire wound resistors should be
avoided because of their additional series inductance. Use
of sockets should also be avoided if possible. Sockets add
parasitic inductance and capacitance that can result in
compromised performance. Minimizing parasitic capacitance
at the amplifier's inverting input pin is very important. The
feedback resistor should be placed very close to the
inverting input pin. Strip line design techniques are
recommended for the signal traces.
S
- pin becomes the negative
S
- pin is
October 30, 2007
FN7313.6
S
+