3.4GHz to 3.8GHz SiGe

Low-Noise Amplifier/PA Predriver

8

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Typical Operating Characteristics (continued)

7

9

8

11

10

12

13

3.0

4.0

3.5

4.5

5.0

5.5

OUTPUT P1dB POINT vs. SUPPLY VOLTAGE

(HIGH-GAIN MODE)

SUPPLY VOLTAGE (V)

°C

°C

°C

PA PREDRIVER CIRCUIT

-25

-15

-20

-5

-10

5

0

10

-10.0

-5.0

0

5.0

OUTPUT POWER vs. INPUT POWER

(LOW-GAIN MODE)

INPUT POWER (dBm)

PA PREDRIVER CIRCUIT

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

3.4

3.5

3.6

3.7

3.8

INPUT VSWR vs. FREQUENCY

FREQUENCY (GHz)

HIGH GAIN

LOW GAIN

PA PREDRIVER CIRCUIT

Pin Description

PIN

NAME

FUNCTION

1, 2, 4, 7,

EP

GND

Ground. Connect to ground plane with a low-inductance connection. Solder exposed paddle evenly

to the board ground plane.

3

RFIN

RF Input Port to Amplifier. Requires a matching network and a DC-blocking capacitor that may be

part of this network. See Figure 1 for recommended component values.

5

BIAS

and supply current of the amplifier.

6

RFOUT

RF Open-Collector Output Port of Amplifier. Requires a matching network composed of an

values.

8

SHDN

Shutdown Control Logic-Level Input. A logic high enables the device for normal operation. A logic

low places the device in low-power shutdown mode.

9

GAIN

Gain Control Logic-Level Input. A logic high places the device in high-gain mode. A logic low

places the device in low-gain mode, reducing the gain by 25dB.

10

Power Supply Input. Bypass directly to ground with a capacitor as close to the supply pin as

possible. See Figure 1 for recommended component values.