kh205 Fairchild Semiconductor, kh205 Datasheet - Page 6

• Manufacturer Part Number: kh205
• Description: Overdrive-protected Wideband Op Amp
• Manufacturer: Fairchild Semiconductor

DATA SHEET
where:
Realized
dependent upon the external circuit.
common external circuit choices that improve 3
distortion are:
Printed Circuit Layout
As with any high frequency device, a good PCB layout
will enhance the performance of the KH205. Good
ground plane construction and power supply bypassing
close to the package are critical to achieving full perfor-
mance. In the non-inverting configuration, the amplifier is
sensitive to stray capacitance to ground at the inverting
input. Hence, the inverting node connections should be
small with minimal stray capacitance to the ground plane
or other nodes. Shunt capacitance across the feedback
resistor should not be used to compensate for this effect.
General layout and supply bypassing play major roles in
6
s
s
s
s
s
s
s
s
IP3
the load.
P
HD3
fundamental, -dBc.
dBm is the power in mW, at the load,
expressed in dB.
short and equal return paths from the load
to the supplies.
de-coupling capacitors of the correct value.
higher load resistance.
a lower ratio of the output swing to the
power supply voltage.
o
= output power level, dBm at the load.
o
third-order
rd
= third-order output intercept, dBm at
= third-order distortion from the
output
distortion
Some of the
is
rd
highly
order
high frequency performance. Follow the steps below as
a basis for high frequency layout:
Evaluation PC boards (part number 730008 for inverting,
730009 for non-inverting) for the KH205 are available to
aid in device testing.
s
s
s
s
s
s
Include 6.8µF tantalum and 0.1µF ceramic
capacitors on both supplies.
Place the 6.8µF capacitors within 0.75
inches of the power pins.
Place the 0.1µF capacitors less than 0.1
inches from the power pins.
Remove the ground plane under and
around the part, especially near the input
and output pins to reduce parasitic
capacitance.
Minimize all trace lengths to reduce series
inductances.
Use flush-mount printed circuit board pins
for prototyping, never use high profile DIP
sockets.
REV. 1A February 2001
KH205