External Circuitry

Label

Value

Purpose

C1 - C5

1000 pF

Low frequency bypass

C6 - C8

68 pF

RF bypass

C9

1.5 pF

Output power tuning

C10

15 pF

Reduces low frequency gain

R1

2.7 k

Ω

Voltage divider to V

G2

R2

1.5 k

Ω

Voltage divider to V

G2

R3

150

Ω

Reduces low frequency gain

Tline

0.250 in. long

Power match

250 mW Linear Power Amplifier and T/R Switch

AM55-0004

Specifications Subject to Change Without Notice

V 2.00

M/A-COM Inc.

s

1011 Pawtucket Boulevard, Lowell, MA 01853 USA

s

Telephone: 800-366-2266

6

Recommended PCB Configuration

Layout View

Cross-Section View

External Circuitry Parts List

All off-chip components are low-cost surface mount components obtainable from

multiple sources. (0.020 in. x 0.040 in. or 0.030 in. x 0.050 in.)

V

DD1

C8

C5

VSW

Tx IN

Rx OUT

ANT IN/OUT

1

2

3

4

5

6

7

8

9

10

11

12

13

14

28

27

26

25

24

23

22

21

20

19

18

17

16

15

C4

Save Tx

VSW

R2

R1

C1

C6

V

G2

C9

PA OUT

C10

C2

PA IN

C3

C7

R3

TLine

The PCB dielectric between RF traces and RF ground layers

should be chosen to reduce RF discontinuities between

50-

Ω lines and package pins. M/A-COM recommends an

FR-4 dielectric thickness of 0.008 in. (0.2 mm), yielding a

50-

Ω line width of 0.015 in. (0.38 mm). The recommended

metalization thickness is 1 oz. copper.

Shaded traces are vias to DC routing layer and traces on DC

routing layer.

Biasing Procedure

The AM55-0004 requires that V

any

V

procedure is not followed. All FETs in the PA will draw

excessive current and damage internal circuitry.

RF Traces + Components

RF Ground

DC Routing

Customer Defined

C1

C6

C9

C2

C10

C7

R2

R1

R3

C3

C4

C5

C8

0.700 in.

0.490 in.

Pin 1