Specifications and information are subject to change without notice

WJ Communications, Inc • Phone 1-800-WJ1-4401 • FAX: 408-577-6621 • e-mail: sales@wj.com • Web site: www.wj.com

Page 2 of 4 March 2007

AP622

UMTS-band 4W HBT Amplifier Module

Evaluation Board Bias Procedure

The following bias procedure is recommended to ensure proper functionality of AP622 in a laboratory environment. The sequencing is not

required in the final system application.

28V

28V

GND

5V

Turn-on Sequence:

1.

Attach input and output loads onto the evaluation board.

2.

Turn on power supply Vcc = +28V.

3.

Turn on power supply Vpd = +5V.

4.

Turn on RF power.

Turn-off Sequence:

1.

Turn off RF power.

2.

Turn off power supply Vpd = +5V.

3.

Turn off power supply Vcc = +28V.

Notes:

1.

Vpd is used as a reference for the internal active bias circuitry. It can be used to turn on/off the amplifier.