Specifications and information are subject to change without notice

WJ Communications, Inc

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Page 3 of 11 May 2007 ver 1

AP602

High Dynamic Range 4W 28V HBT Amplifier

Application Circuit PC Board Layout

PCB Material: 0.0147” Rogers Ultralam 2000, single layer, 1 oz Cu,

Baseplate Configuration

Notes:

1. Please note that for reliable operation, the evaluation board will have to be mounted to a much larger

heat sink during operation and in laboratory environments to dissipate the power consumed by the

device. The use of a convection fan is also recommended in laboratory environments.

2. The area around the module underneath the PCB should not contain any soldermask in order to

maintain good RF grounding.

3. For proper and safe operation in the laboratory, the power-on sequencing is recommended.

Evaluation Board Bias Procedure

Following bias procedure is recommended to ensure proper functionality of AP602 in a laboratory environment. The sequencing is not

required in the final system application.

Bias.

Voltage (V)

Vcc

+28

Vbias

+5

Vpd

+5

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 Vbias = +5V. At this point, the only current drawn by the device is leakage current (< 25µA).

4.

Turn on power supply Vpd = +5V. Power supply Vcc should now be drawing typical Icq = 80 mA.

5.

Turn on RF power.

Turn-off Sequence:

1.

Turn off RF power.

2.

Turn off power supply Vpd = +5V.

3.

Turn off power supply Vbias = +5V.

4.

Turn off power supply Vcc = +28V.

Notes:

1.

Icq can be adjusted with the resistor R2 from the Vpd (+5V) supply and the PIN_VPD (pin14) of the amplifier. Increasing R2

results in a lower Icq. Icq should not be increased above 160mA.

2.

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

quiescent current setting. Ipd can be up to 4mA at a quiescent current setting of 160mA.

3.

Vbias should be maintained fixed at +5V. Ibias will change based on RF input power level. It can be up to 4mA on the AP602.

Ipd vs Icq

0

1

2

3

4

0

40

80

120

160

200

Icq Setting (mA)

Ibias vs Output Power

0

1

2

3

4

22

24

26

28

30

32

Output Average Power (dBm)