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RFUV1002

DS110908

7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical

support, contact RFMD at (+1) 336-678-5570 or sales-support@rfmd.com.

Typical Bias Sequence and Gain Control

Optimum performance is achieved using sequential bias. At maximum gain (VC1 ,VC4), VC2 and VC3 are set at -3V. (VC1 ,VC4),

VC2 and VC3 are biased in sequence. The first dynamic range is achieved by setting VC2 and VC3 at -3V and varying (VC1

,VC4) over the (-3 to 0V) range as shown in the table below. Similarly second dynamic range is achieved by setting (VC1 ,VC4)

at 0V, VC3 at -3 and varying VC2 over the (-3 to 0V) range. Finally third dynamic range is achieved by setting (VC1 ,VC4) and

VC2 at 0V and varying VC3 over the (-3 to 0V) range.

Better NF at minimum gain is achieved using bias sequence 2.

Bias Sequence 1 (Typical)

Gmax

Gmin

VC1, VC4

-3

-2

-1

0

000

000

VC2

-3

-3-3-3

-2-1

0

0

0

0

VC3

-3

-3-3-3

-3-3

-3-2-1

0

Bias Sequence 2

Gmax

Gmin

VC1, VC4

-3

-2.5

-2

-1.5

-1-1-1-1-1

-1-1

-1

-1

-1

-1-1

VC2

-3

-3

-3

-3

-3

-2.5

-2

-1.5

-1

-0.5

-0.5

-0.5

-0.5

-0.5

-0.5

-0.5

VC3

-3

-3-3-3

-3-3-3-3-3

-3

-2.5

-2

-1.5

-1

-0.5

0