Introduction
LDMOS technology allows the manufacturing of high efficiency and high gain amplifiers for FM transmitters. LDMOS has proven advantages against bipolar devices in terms of higher gain, efficiency, linearity, and biasing simpleness that lower the overall system cost and make them attractive for high volume businesses demanding low cost RF power transistor solutions. Thanks to these advantages, LDMOS RF power transistors are the proven mainstay in the power amplifier business of the cellular base station today. The device used for the present characterization, SD57045, an STMicroelectronics product, is a lateral current, double diffused MOS transistor that delivers 45 W under 28 V supply. It is unmatched from DC to 1 Ghz making it eligible for a variety of applications, especially for high performance, low cost FM driver applications. This application note documents the feasibility of a low cost 900 MHz cellular device as a commercial FM driver. The key advantages of LDMOS technology are improved thermal resistance and reduced source output inductance. The wire-bonded connections to the external circuitry (DMOS config.) are no longer required because the source at the chip surface is connected to the substrate by the diffusion of a highly doped p-type region. Consequently, LDMOS has excellent high frequency response because of its high fT and superior gain due to the low feedback capacitance and reduced source inductance. An additional advantage of the LDMOS structure is that beryllium oxide (BeO), a toxic electrical insulator required to isolate the drain with DMOS transistors, is no longer needed. Hence, not only the thermal resistance is improved, but package cost and environmental impact are significantly reduced. Finally, in an LDMOS, the parasitic bipolar has been nullified guaranteeing good ruggedness, efficiency and high current handling capability.
General description
200 W LDMOS avionics power transistor for transmitter applications at frequencies from 1030 MHz to 1090 MHz.
Features
■ Typical pulsed class-AB performance at a frequencies from 1030 MHz to 1090 MHz, a
supply voltage of 36 V and an IDq of 150 mA:
◆ Load power ≥ 200 W
◆ Gain ≥ 13 dB
◆ Efficiency ≥ 45 %
◆ Rise time ≤ 50 ns
◆ Fall time ≤ 50 ns
■ High power gain
■ Easy power control
■ Excellent ruggedness
■ Source on mounting flange eliminates DC isolators, reducing common mode
inductance
Applications
■ avionics transmitter applications in the 1030 MHz to 1090 MHz frequency range.
General description
200 W LDMOS avionics power transistor for transmitter applications at frequencies from 1030 MHz to 1090 MHz.
Features
■ Typical pulsed class-AB performance at a frequencies from 1030 MHz to 1090 MHz, a
supply voltage of 36 V and an IDq of 150 mA:
◆ Load power ≥ 200 W
◆ Gain ≥ 13 dB
◆ Efficiency ≥ 45 %
◆ Rise time ≤ 50 ns
◆ Fall time ≤50 ns
■ High power gain
■ Easy power control
■ Excellent ruggedness
■ Source on mounting flange eliminates DC isolators, reducing common mode
inductance
Applications
■ avionics transmitter applications in the 1030 MHz to 1090 MHz frequency range.
General description
1000W LDMOS pulsed power transistor intended for avionics transmitter applications in the 960 MHz to 1215 MHz frequency range such as Mode-S, TCAS, JTIDS, DME and TACAN.
Features and benefits
■ Easy power control
■ Integrated ESD protection
■ High flexibility with respect to pulse formats
■ Excellent ruggedness
■ High efficiency
■ Excellent thermal stability
■ Designed for broadband operation (960 MHz to 1215 MHz)
■ Internally matched for ease of use
■ Compliant to Directive 2002/95/EC, regarding Restriction of Hazardous Substances
(RoHS)
Applications
■ 1000 W LDMOS pulsed power transistor intended for Mode-S, TCAS, JTIDS, DME
and TACAN applications in the 960 MHz to 1215 MHz frequency range
General description
1000W LDMOS pulsed power transistor intended for avionics transmitter applications in the 960 MHz to 1215 MHz frequency range such as Mode-S, TCAS, JTIDS, DME and TACAN.
Features and benefits
■ Easy power control
■ Integrated ESD protection
■ High flexibility with respect to pulse formats
■ Excellent ruggedness
■ High efficiency
■ Excellent thermal stability
■ Designed for broadband operation (960 MHz to 1215 MHz)
■ Internally matched for ease of use
■ Compliant to Directive 2002/95/EC, regarding Restriction of Hazardous Substances
(RoHS)
Applications
■ 1000 W LDMOS pulsed power transistor intended for Mode-S, TCAS, JTIDS, DME
and TACAN applications in the 960 MHz to 1215 MHz frequency range
General description
200 W LDMOS avionics power transistor for transmitter applications at frequencies from 1030 MHz to 1090 MHz.
Features and benefits
■ Typical pulsed class-AB performance at a frequencies from 1030 MHz to 1090 MHz,
a supply voltage of 36 V and an IDq of 150 mA:
◆ Load power ≥ 200 W
◆ Gain ≥ 13 dB
◆ Efficiency ≥ 45 %
◆ Rise time ≤ 50 ns
◆ Fall time ≤ 50 ns
■ High power gain
■ Easy power control
■ Excellent ruggedness
■ Source on mounting flange eliminates DC isolators, reducing common mode
inductance
■ Compliant to Directive 2002/95/EC, regarding Restriction of Hazardous Substances
(RoHS)
Applications
■ avionics transmitter applications in the 1030 MHz to 1090 MHz frequency range.
General description
200 W LDMOS avionics power transistor for transmitter applications at frequencies from 1030 MHz to 1090 MHz.
Features and benefits
■ Typical pulsed class-AB performance at a frequencies from 1030 MHz to 1090 MHz,
a supply voltage of 36 V and an IDq of 150 mA:
◆ Load power ≥ 200 W
◆ Gain ≥ 13 dB
◆ Efficiency ≥ 45 %
◆ Rise time ≤ 50 ns
◆ Fall time ≤ 50 ns
■ High power gain
■ Easy power control
■ Excellent ruggedness
■ Source on mounting flange eliminates DC isolators, reducing common mode
inductance
■ Compliant to Directive 2002/95/EC, regarding Restriction of Hazardous Substances
(RoHS)
Applications
■ avionics transmitter applications in the 1030 MHz to 1090 MHz frequency range.
General description
500 W LDMOS power transistor intended for avionics transmitter applications in the 960 MHz to 1215 MHz range such as Mode-S, TCAS, JTIDS, DME and TACAN.
Features and benefits
■ Typical pulsed RF performance at a frequency of 960 MHz to 1215 MHz, a supply
voltage of 50 V, an IDq of 100 mA, a tp of 128 μs with δ of 10 %:
◆ Output power = 450 W
◆ power gain = 17 dB
◆ Efficiency = 50 %
■ Easy power control
■ Integrated ESD protection
■ High flexibility with respect to pulse formats
■ Excellent ruggedness
■ High efficiency
■ Excellent thermal stability
■ Designed for broadband operation (960 MHz to 1215 MHz)
■ Internally matched for ease of use
■ Compliant to Directive 2002/95/EC, regarding Restriction of Hazardous Substances
(RoHS)
Applications
■ L-band power amplifiers for radar applications in the 1.2 GHz to 1.4 GHz frequency
range
General description
500 W LDMOS power transistor intended for avionics transmitter applications in the 960 MHz to 1215 MHz range such as Mode-S, TCAS, JTIDS, DME and TACAN.
Features and benefits
■ Typical pulsed RF performance at a frequency of 960 MHz to 1215 MHz, a supply
voltage of 50 V, an IDq of 100 mA, a tp of 128 μs with δ of 10 %:
◆ Output power = 450 W
◆ power gain = 17 dB
◆ Efficiency = 50 %
■ Easy power control
■ Integrated ESD protection
■ High flexibility with respect to pulse formats
■ Excellent ruggedness
■ High efficiency
■ Excellent thermal stability
■ Designed for broadband operation (960 MHz to 1215 MHz)
■ Internally matched for ease of use
■ Compliant to Directive 2002/95/EC, regarding Restriction of Hazardous Substances
(RoHS)
Applications
■ A-band power amplifiers for radar applications in the 960 MHz to 1215 MHz frequency
range
General description
Silicon N-channel enhancement mode LDMOS transistor encapsulated in a 2-lead SOT502A flange package with a ceramic cap. The common source is connected to the mounting flange.
Features and benefits
■ High power gain
■ Easy power control
■ Excellent ruggedness
■ Source on mounting base eliminates DC isolators, reducing common mode
inductance.
Applications
■ avionics transmitter applications in the 960 MHz to 1215 MHz frequency range such
as Mode-S, TCAS and JTIDS, DME or TACAN.
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