Place the 1nF power-supply decoupling capacitors

between the star connection and the smaller bypass

capacitors and close to the IC. Larger trace lengths

between the decoupling capacitors and the IC increase

the parasitic trace inductance, which, when combined

tank and introduce instability in the MHz range. If this

happens, you can add a small-value resistor (~10

Ω),

between the 1nF capacitor and ground to de-Q the

capacitor and dampen the oscillation.

2.5GHz, 22dBm/20dBm Power Amplifiers with

Analog Closed-Loop Power Control

8

_______________________________________________________________________________________

C8

C9

1nF

C3

1nF

C2

10nF

RFIN

R2

1k

Ω

C5

10pF

C10

C11

1nF

C6

RFOUT

T2

T1

C7

C1

10

µF

C4

27pF

SHDN

DAC

R2

2.5k

Ω

A1

PC

RFIN/

SHDN

B1

C1

A2

B2

C2

A3

B3

C3

GND

GND

RFOUT

GND

GND

TRANSCEIVER IC

MAX2244

MAX2245

MAX2246

T3

T4

Figure 1. MAX2244/MAX2245/MAX2246 Typical Application Circuit

COMPONENT

MAX2244

MAX2245

MAX2246

C6

10pF

5.6pF

10pF

C7

1.2pF

1.2pF

1.3pF

C8

5pF

5pF

27pF

C10

100pF

100pF

27pF

T1

50

Ω, 17.6°

50

Ω, 18°

50

Ω, 25°

T2

50

Ω, 50°

50

Ω, 53°

50

Ω, 50°

T3

50

Ω, 5.3°

50

Ω, 5.3°

50

Ω, 5.3°

T4

50

Ω, 5.3°

50

Ω, 5.9°

50

Ω, 8.9°

Table 1. Typical Application Circuit

Component Values

Note: Electrical lengths given for 2.4GHz.