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STEVAL-TDR028V1
RF power amplifier demonstration board based on the STAC2942B
Features
■ Excellent thermal stability
■ Frequency: 87.5 - 108 MHz
■ Supply voltage: 48 V
■ Output power: 370 W min.
■ Gain: 20 dB typ.
■ Efficiency: 77% typ.
■ Harmonics: - 30 dBc max.
■ Gain flatness: ± 0.7 dB max.
Description
Table 1. Device summary
The STEVAL-TDR028V1 is an RF broadband
power amplifier intended for FM broadcast radio
transmitters over the 87.5 to 108 MHz band, using
an STAC2942B gold metallized N-channel MOS
field-effect transistor.
STEVAL-TDR028V1
Order code
STEVAL-TDR028V1
The STEVAL-TDR028V1 is designed in
cooperation with InnovAction S.r.l in Italy.
June 2010 Doc ID 17469 Rev 1 1/11
www.st.com
11
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Contents STEVAL-TDR028V1
Contents
1 Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3 Circuit layout and connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4 STAC2942B mounting recommendations . . . . . . . . . . . . . . . . . . . . . . . . 5
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.2 Heatsink selection and preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.3 Surface conditions of the mounting base . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.4 Thermal interface material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.5 Seating plane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.6 Printed circuit board (PCB) considerations . . . . . . . . . . . . . . . . . . . . . . . . 7
4.7 Package attachment to thermal base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.7.1 Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.7.2 Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.8 Electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.9 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2/11 Doc ID 17469 Rev 1
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STEVAL-TDR028V1 Electrical data
1 Electrical data
1.1 Maximum ratings
Table 2. Absolute maximum ratings
Symbol Parameter Value Unit
P
T
P
P
IN
OUT
STG
T
C
I
DD
DISS
Input power 7 W
Output power 400 W
Storage temperature range -20 to +70 °C
Operating base plate temperature 0 to +70 °C
Drain current 12 A
Power dissipation 250 W
2 Electrical characteristics
TA = +25 oC, VDD = 48 V, I
Table 3. Electrical specification
Symbol Test conditions Min Typ Max Unit
Frequency Frequency range 87.5 108 MHz
P
OUT
Gain P
ND P
H2 2
H3 3
FL Gain flatness @ P
= 370 W 20 ± 1 dB
OUT
= 370 W 77 %
OUT
nd
harmonic @ P
rd
harmonic @ P
= 2 x 200 mA
dq
= 370 W -35 dBc
OUT
= 370 W -41 dBc
OUT
= 370 W ± 0.7 dB
OUT
370 400 W
Doc ID 17469 Rev 1 3/11
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Circuit layout and connections STEVAL-TDR028V1
3 Circuit layout and connections
Figure 1. Circuit layout and connections
4/11 Doc ID 17469 Rev 1