PRELIMINARY

FPD4000AF

Phone: +1 408 850-5790

http:// www.filcs.com

Revised: 08/09/04

Fax: +1 408 850-5766

Email: sales@filcsi.com

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BIASING GUIDELINES

Active bias circuits provide good performance stabilization over variations of operating

temperature, but require a larger number of components compared to self-bias or dual-biased.

Such circuits should include provisions to ensure that Gate bias is applied before Drain bias,

otherwise the pHEMT may be induced to self-oscillate. Contact your Sales Representative for

additional information.

Dual-bias circuits are relatively simple to implement, but will require a regulated negative

voltage supply for depletion-mode devices such as the FPD4000AF.

Self-biased circuits employ an RF-bypassed Source resistor to provide the negative Gate-Source

bias voltage, and such circuits provide some temperature stabilization for the device. A nominal

value for circuit development is 0.7

Ω for the recommended 720mA operating point. This

approach will require a DC Source resistor capable of at least 365mW dissipation.

The recommended 720mA bias point is nominally a Class AB mode. A small amount of RF gain

expansion prior to the onset of compression is normal for this operating point.

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PACKAGE OUTLINE

(dimensions in millimeters – mm)

All information and specifications subject to change without notice.

PACKAGE MARKING CODE

Example:

f1ZD

P2F

f = Filtronic

1ZD = Lot and Date Code

P2F = Status, Part Code, Part Type

Status: D=Development P = Production

Part Code denotes model (e.g. FPD4000AF)

Part Type: F = FET (pHEMT)