NOISE FIGURE

vs

SOURCE RESISTANCE

18

14

0

20

16

12

Rs – Source Resistance – Ω

10

100

1k

10k

TA = 25°C

8

4

10

6

2

NF

+ 10log 1 )

e

n

2

) IN )

R

S

2

4 kTR

S

NF

+ 10log

e

2

ni

e

Rs

2

THS6012

www.ti.com

SLOS226F – SEPTEMBER 1998 – REVISED JUNE 2012

Because the dominant noise components are generally the source resistance and the internal amplifier noise

voltage, we can approximate noise figure as:

Figure 42 shows the noise figure graph for the THS6012.

Figure 42. Noise Figure vs Source Resistance

Copyright © 1998–2012, Texas Instruments Incorporated

21