TSH346

Power supply considerations and improvement of the PSRR

9/18

Figure 22.

Circuit for noise rejection improvement measurement

Figure 23 shows how the power supply noise rejection evolves versus frequency depending

on how carefully the power supply decoupling is achieved.

Figure 23.

Power supply noise rejection

50

+5 V

50

TSH346

AGILENT

4395A

S

R

A

Coil

T- bias

+

AM00825

C

LF

C

HF

10k

100k

1M

10M

100M

-80

-70

-60

-50

-40

-30

-20

-10

0

coil=560µH

no coil

Vcc=5V(dc)+0.2Vp-p(ac)

Decoupling capacitor: 10µF+100nF

Load=150

Ω

Noise rejection=20 log (

Frequency (Hz)