TSH690_01 datasheet(8/14 Pages) STMICROELECTRONICS

Part #	TSH690

Description	40MHz to 1GHz AMPLIFIER

PDF	14 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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8 / 14 page

TSH690

8/14

DETERMINING VBIAS AND R1 AT 450 MHz

Using the 450 MHz curves, you can easily deter-

mine VBIAS voltage and R1 to obtain the desired

power gain S21.

For a given gain S21 and a given supply voltage

VCC, you can determine the corresponding

VBIAS.using the curve ’Gain vs VBIAS’ in the ’450

MHz operation’ section.

It’s generally more convenient to supply the Vbias

from VCC than generate a separate voltage. You

just need to add the R1 resistor beetween the

VBIAS pin and VCC.

Using the curve ’Supply current vs Bias voltage’

you can determine the current IBIAS corresponding

to a VBIAS . R1 can calculated by:

R1 = (VCC - VBIAS ) / IBIAS.

One the same curve, you will find the total current

supply Icc versus the biasing conditions.

Figure 5 : Demo board silk screen (not to scale)

Figure 6 : Demo board top side (not to scale )

TSH690 Datasheet(PDF) 8 Page - STMicroelectronics