Power Transistor

RT230PD

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Version 5.2

Biasing Circuits for GaAs HFET Power Amplifiers

This circuit below normally operates GaAs Power Amplifier and it is one of the circuits for stable operation and satisfactory

performance. It is structured by the parts for constant current operation.

Main functions of this circuit :

Negative Voltage Generator

Power Sequencing mode(Negative before positive)

Constant operating current

Constant operating current circuit is structured by low cost components. It will operate of constant current regardless of any

temperature changes. R3 should carefully be taken by power dissipation.

Pin No

Value

Description

Maker

Quantity

Q1

N/A

P-channel MOSFET, IRLML5203

IRF

1

Q2

N/A

Dual PNP, UMT1N

Rohm

1

Q3

N/A

DC-DC Converter With Sequency mode, LTC1261

Linear Tech

1

R1

10kΩ

0603, 1/16W

Rohm

1

R2

24Ω

0603, 1/16W

Rohm

1

R3

0.5Ω

1206, 1 W

Rohm

1

R4

1.5KΩ

0603, 1/16W

Rohm

1

R5

1KΩ

0603, 1/16W

Rohm

1

R6

430Ω

0603, 1/16W

Rohm

1

R7

10kΩ

0603, 1/16W

Rohm

1

C1,C2

0.1uF

0603

Murata

1

C3,C4,C5

4.7uF

1206

Taiyo Yuden

3

L1

1uH

0805

Taiyo Yuden

1