Microsemi reserves the right to change, without notice, the specifications and information contained herein. Visit
our web site at www.microsemi.com or contact our factory direct.
GENERAL DESCRIPTION
The MDS70 is a COMMON BASE bipolar transistor. It is designed for
MODE S pulsed systems in the frequency band 1030-1090 MHz. The device
has gold thin-film metallization for proven highest MTTF. The transistor
includes input prematch for broadband capacity. Low thermal resistance
package reduces junction temperature, extends life.
CASE OUTLINE
55CX, STYLE 1
ABSOLUTE MAXIMUM RATINGS
Maximum Power Dissipation @ 25oC2 225 Watts
Maximum Voltage and Current
BVces Collector to Base Voltage 65 Volts
BVebo Emitter to Base Voltage 3.5 Volts
Ic Collector Current 5.0 Amps
Maximum Temperatures
Storage Temperature - 65 to + 150oC
Operating Junction Temperature + 200oC
ELECTRICAL CHARACTERISTICS @ 25 OC
SYMBOL
CHARACTERISTICS TEST CONDITIONS MIN TYP
MAX
UNITS
Pout
Power Out 70
95 Watts
Pg Power Gain 10.3 11.65 dB
RT Rise Time 80 ns
ηc Collector Efficiency
F = 1030-1090 MHz
Vcc = 50 Volts
Pin = 6.5W
Pulse Mod: Mode S2
35 %
VSWR1 Load Mismatch Tolerance 1090 MHz 5:1
BVebo
Emitter to Base Breakdown
Ie = 5 mA 3.5 Volts
BVces Collector to Emitter Breakdown Ic = 25 mA 65 Volts
hFE DC - Current Gain Ic = 500 mA, Vce = 5 V 20
θjc1 Thermal Resistance
0.8
oC/W
Notes: 1) At rated pulse conditions 2) Mode S Burst: 0.5us (on/off), N=128, Per=6.4ms; LTDC=1%
Rev C: August 2010
MDS70
70 Watts, 50 Volts, Pulsed
Avionics 1030 - 1090MHz
Microsemi reserves the right to change, without notice, the specifications and information contained herein. Visit
our web site at www.microsemi.com or contact our factory direct.
MDS70 (Pout vs Pin )
0
10
20
30
40
50
60
70
80
90
100
110
012345678910
Pin(W)
Pout(W)
1030MHz (N=1) 1030MHz (N=128) 1090MHz (N=1) 1090MHz (N=128)
MDS70 (Ef fic vs Pin)
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
012345678910
Pin(W)
Effic(%)
1030MHz 1090MHz
Microsemi reserves the right to change, without notice, the specifications and information contained herein. Visit
our web site at www.microsemi.com or contact our factory direct.
Microsemi reserves the right to change, without notice, the specifications and information contained herein. Visit
our web site at www.microsemi.com or contact our factory direct.
MDS70 IMPEDANCE DATA:
FREQUENCY Zsource (ohms) Zload (ohms)
1030 3.0 – j4.8 5.3 – j1.2
1090 2.8 – j4.5 6.2 – j1.2
Zsource Zload
Microsemi reserves the right to change, without notice, the specifications and information contained herein. Visit
our web site at www.microsemi.com or contact our factory direct.
