2.7V, Single-Supply, Cellular-Band

Linear Power Amplifiers

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13

16

15

14

13

12

11

10

9

1

2

3

4

5

6

7

8

RFIN

TX

POWER

L1

C1

SHDN

C3

C4

C6

L6

L4

R1

C12

C11

R2

C13

L7

C7

RFOUT

C9

OPTIONAL

NOISE-REDUCTION

CIRCUIT

MAX2265

L3

OPTIONAL TB CIRCUIT

Figure 2. MAX2265 Typical Application Circuit

each device; suggested component values, suppliers,

and part numbers are listed in Table 1. These values

are optimized for best simultaneous efficiency and

return loss performance. Use high-quality components

in these matching circuits for greatest efficiency.

Layout and Power-Supply Bypassing

A properly designed PC board is essential to any

RF/microwave circuit. Be sure to use controlled imped-

ance lines on all high-frequency inputs and outputs.

Proper grounding of the GND pins is fundamental; if the

PC board uses a topside RF ground, connect all GND

pins (especially the TSSOP package exposed GND pad)

directly to it. On boards where the ground plane is not on

the component side, it’s best to connect all GND pins to

the ground plane with plated through-holes close to the

package.

To minimize coupling between different sections of the

system, the ideal power-supply layout is a star configu-

ration with a large decoupling capacitor at a central

board. A second bypass capacitor with low ESR at the

RF frequency of operation is located at the end of each

trace. This arrangement provides local decoupling at

Input and output impedance-matching networks are

very sensitive to layout-related parasitics. It is important

to keep all matching components as close to the IC as

possible to minimize the effects of stray inductance

and stray capacitance of PC board traces.