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Philips Semiconductors

Product specification

SA5205A

Wide-band high-frequency amplifier

1997 Nov 07

 8

POWER DISSIPATION CONSIDERATIONS

When using the part at elevated temperature, the engineer should con-
sider the power dissipation capabilities.

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

CC

 versus V

CC

 curves. The supply current is

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 SA5205A 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

CC

 pins on the SO package).

The power supply should be decoupled with a capacitor as close to
the V

CC

 pins as possible and an RF choke should be inserted

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

CC

=6V, the input is

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

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 SA5205A 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 SA5205A to other
high-frequency amplifiers.

5205A

VOUT

VIN

VCC

AC

COUPLING

CAPACITOR

RF CHOKE

DECOUPLING
CAPACITOR

AC

COUPLING

CAPACITOR

SR00232

Figure 18.  Circuit Schematic for Coupling and Power Supply

Decoupling

a.  Two-Port Network Defined

b.

S21

S12

S22

S11

POWER AVAILABLE FROM
GENERATOR AT INPUT PORT

POWER REFLECTED
FROM INPUT PORT

S11 =

POWER REFLECTED

FROM OUTPUT PORT

POWER AVAILABLE FROM

GENERATOR AT OUTPUT PORT

S

22 

=

REVERSE TRANSDUCER

POWER GAIN

S12 =

S11 — INPUT RETURN LOSS

S12 — REVERSE TRANSMISSION LOSS

          OSOLATION

S21 — FORWARD TRANSMISSION LOSS

          OR INSERTION GAIN

S21 

 

=       TRANSDUCER POWER GAIN

S22

 

— OUTPUT RETURN LOSS

SR00233

Figure 19.  

Содержание SA5205A

Страница 1: ...Philips Semiconductors SA5205A Wide band high frequency amplifier Product specification Replaces data of February 24 1992 1997 Nov 07 INTEGRATED CIRCUITS IC17 Data Handbook ...

Страница 2: ...outline SO package to further reduce parasitic effects No external components are needed other than AC coupling capacitors because the SA5205A is internally compensated and matched to 50 and 75Ω The amplifier has very good distortion specifications with second and third order intermodulation intercepts of 24dBm and 17dBm respectively at 100MHz The device is ideally suited for 75Ω cable television ...

Страница 3: ...216 Figure 2 Equivalent Schematic ABSOLUTE MAXIMUM RATINGS SYMBOL PARAMETER RATING UNIT VCC Supply voltage 9 V VAC AC input voltage 5 VP P TA Operating ambient temperature range SA grade 40 to 85 C PDMAX Maximum power dissipation TA 25 C still air 1 2 D package 780 mW NOTES 1 Derate above 25 C at the following rates D package at 6 2mW C 2 See Power Dissipation Considerations section ...

Страница 4: ...sertion gain f 100MHz Over temperature 17 16 5 19 21 21 5 dB S11 Input return loss f 100MHz 25 dB S11 Input return loss DC fMAX 12 dB S22 Output return loss f 100MHz 27 dB S22 Output return loss DC fMAX 12 dB S12 Isolation f 100MHz 25 dB S12 Isolation DC fMAX 18 dB tR Rise time 500 ps tP Propagation delay 500 ps BW Bandwidth 0 5dB 450 MHz fMAX Bandwidth 3dB 550 MHz Noise figure 75Ω f 100MHz 4 8 dB...

Страница 5: ... VCC 8V ZO 50Ω 25 20 15 10 101 2 4 6 8 2 4 6 8 102 103 FREQUENCY MHz SR00223 Figure 6 Insertion Gain vs Frequency S21 OUTPUT LEVEL dBm FREQUENCY MHz ZO 50Ω TA 25oC VCC 8V VCC 7V VCC 6V VCC 5V 2 3 4 5 6 7 8 9 10 11 1 0 1 2 3 4 5 6 101 2 4 6 8 2 4 6 8 102 103 SR00218 Figure 7 Saturated Output Power vs Frequency OUTPUT LEVEL dBm VCC 8V VCC 7V VCC 6V VCC 5V ZO 50Ω TA 25oC 10 9 8 7 6 5 4 3 2 1 0 1 2 3 ...

Страница 6: ...10 101 2 4 6 8 102 2 4 6 8 103 OUTPUT INPUT FREQUENCY MHz VCC 6V ZO 50Ω TA 25oC INPUT RETURN LOSS dB OUTPUT RETURN LOSS dB SR00229 Figure 13 Input S11 and Output S22 Return Loss vs Frequency VCC 6V ZO 50Ω TA 25oC 10 15 20 25 30 ISOLATION dB FREQUENCY MHz 101 2 4 6 8 102 2 4 6 8 103 SR00226 Figure 14 Isolation vs Frequency S12 ISOLATION GAIN dB 15 10 25 20 ZO 75Ω TA 25oC vcc 8v vcc 7v vcc 6v vcc 5v...

Страница 7: ...al to 1V Level shifting is achieved by emitter follower Q3 and diode Q4 which provide shunt feedback to the emitter of Q1 via RF1 The use of an emitter follower buffer in this feedback loop essentially eliminates problems of shunt feedback loading on the output The value of RF1 140Ω is chosen to give the desired nominal gain The DC output voltage VOUT can be determined by VOUT VCC IC2 IC6 R2 4 whe...

Страница 8: ...output should be AC coupled This is because at VCC 6V the input is 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 output pin...

Страница 9: ...ion vs Frequency S12 d S12 Isolation vs Frequency e Input S11 and Output S22 Return Loss vs Frequency f Input S11 and Output S22 Return Loss vs Frequency ISOLATION dB ZO 75Ω TA 25oC VCC 6V 10 15 20 25 30 FREQUENCY MHz 8 101 2 4 6 102 2 4 6 8 103 INPUT RETURN LOSS dB OUTPUT RETURN LOSS dB VCC 6V ZO 75Ω TA 25oC OUTPUT INPUT 40 35 30 25 20 15 10 FREQUENCY MHz 101 2 4 6 8 102 2 4 6 8 103 INSERTION GAI...

Страница 10: ...ntercept and intermodulation ratio is illustrated in Figure 22 which shows product output levels plotted versus the level of the fundamental output for two equal strength output signals at different frequencies The upper line shows the fundamental output plotted against itself with a 1dB to 1dB slope The second and third order products lie below the fundamentals and exhibit a 2 1 and 3 1 slope res...

Страница 11: ...SWR vs Frequency ADDITIONAL READING ON SCATTERING PARAMETERS For more information regarding S parameters please refer to High Frequency Amplifiers by Ralph S Carson of the University of Missouri Rolla Copyright 1985 published by John Wiley Sons Inc S Parameter Techniques for Faster More Accurate Network Design HP App Note 95 1 Richard W Anderson 1967 HP Journal S Parameter Design HP App Note 154 1...

Страница 12: ...Philips Semiconductors Product specification SA5205A Wide band high frequency amplifier 1997 Nov 07 12 SO8 plastic small outline package 8 leads body width 3 9mm SOT96 1 ...

Страница 13: ...ablybeexpected to result in a personal injury Philips Semiconductors and Philips Electronics North America Corporation customers using or selling Philips Semiconductors and Philips Electronics North America Corporation Products for use in such applications do so at their own risk and agree to fully indemnify Philips Semiconductors and Philips Electronics North America Corporation for any damages r...

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