Texas Instruments THS4271 Evaluation Module THS4271EVM THS4271EVM Datenbogen

3-3

If unity gain inverting operation is desired, the user should:

-

Change R6 to 0 

Ω

-

Remove R7

-

Change R4 to 0 

Ω

-

Change R2 to 61.9 

Ω 

(R3 in parallel with R2 equals 50 

Ω

 for termination

of the input)

as shown in Figure 3-3.







 The gain for this circuit with a 50-

Ω

 source is:

V

O

V

I

+ *

R5
R3

when the input voltage is measured at J1.

The input impedance of the stage is 50 

Ω

, as determined by R2 in parallel with

R3.

For the default EVM configuration, power-down reference level is set to
ground through R1. This reference can be set to a different level if R1 is
removed and an external voltage is supplied to J8 as shown in Figure 3-4.