NE5205AD Philips, NE5205AD Datasheet - Page 8

• Manufacturer Part Number: NE5205AD
• Description: Wide-band high-frequency amplifier
• Manufacturer: Philips

Philips Semiconductors
POWER DISSIPATION CONSIDERATIONS
When using the part at elevated temperature, the engineer should con-
sider the power dissipation capabilities of each package.
At the nominal supply voltage of 6V, the typical supply current is
25mA (32mA Max). For operation at supply voltages other than 6V,
see Figure 3 for I
inversely proportional to temperature and varies no more than 1mA
between 25 C and either temperature extreme. The change is 0.1%
per over the range.
The recommended operating temperature ranges are air-mount
specifications. Better heat sinking benefits can be realized by
mounting the D package body against the PC board plane.
PC BOARD MOUNTING
In order to realize satisfactory mounting of the NE5205A to a PC
board, certain techniques need to be utilized. The board must be
double-sided with copper and all pins must be soldered to their
respective areas (i.e., all GND and V
The power supply should be decoupled with a capacitor as close to
the V
between the supply and the device. Caution should be exercised in
the connection of input and output pins. Standard microstrip should
be observed wherever possible. There should be no solder bumps
or burrs or any obstructions in the signal path to cause launching
problems. The path should be as straight as possible and lead
lengths as short as possible from the part to the cable connection.
Another important consideration is that the input and output should
be AC coupled. This is because at V
approximately at 1V while the output is at 3.1V. The output must be
decoupled into a low impedance system or the DC bias on the
output of the amplifier will be loaded down causing loss of output
power. The easiest way to decouple the entire amplifier is by
soldering a high frequency chip capacitor directly to the input and
1992 Feb 24
Wide-band high-frequency amplifier
CC
pins as possible and an RF choke should be inserted
S
11
a. Two-Port Network Defined
CC
versus V
S
S
21
12
CC
curves. The supply current is
CC
CC
=6V, the input is
pins on the SO package).
S
22
S
S
S
S
11
12
21
22
Figure 19.
— INPUT RETURN LOSS
— REVERSE TRANSMISSION LOSS
— FORWARD TRANSMISSION LOSS
— OUTPUT RETURN LOSS
OSOLATION
OR INSERTION GAIN
8
output pins of the device. This circuit is shown in Figure 18. Follow
these recommendations to get the best frequency response and
noise immunity. The board design is as important as the integrated
circuit design itself.
SCATTERING PARAMETERS
The primary specifications for the NE/SA/SE5205A are listed as
S-parameters. S-parameters are measurements of incident and
reflected currents and voltages between the source, amplifier and
load as well as transmission losses. The parameters for a two-port
network are defined in Figure 19.
Actual S-parameter measurements using an HP network analyzer
(model 8505A) and an HP S-parameter tester (models 8503A/B) are
shown in Figure 20.
Values for the figures below are measured and specified in the data
sheet to ease adaptation and comparison of the NE/SA/SE5205A to
other high-frequency amplifiers.
Figure 18. Circuit Schematic for Coupling and Power Supply
V
IN
CAPACITOR
COUPLING
AC
b.
S
S
S
S
11
12
21
22
Decoupling
NE5205A
=
=
=
=
V
CC
GENERATOR AT OUTPUT PORT
TRANSDUCER POWER GAIN
RF CHOKE
POWER AVAILABLE FROM
GENERATOR AT INPUT PORT
NE/SA/SE5205A
REVERSE TRANSDUCER
POWER AVAILABLE FROM
POWER REFLECTED
FROM INPUT PORT
CAPACITOR
FROM OUTPUT PORT
COUPLING
POWER REFLECTED
POWER GAIN
AC
DECOUPLING
CAPACITOR
Product specification
V
OUT
SR00233
SR00232