TS472

Application Information

13/20

4.3

Lower cut-off frequency

a application because of DC voltage blocking.

the value of the input or output capacitors

Note:

pass filter on the input and the 1st order high-pass filter on the output create a 2nd order high-

40db

⁄ decade.

4.4

Low-noise microphone bias source

The TS472 provides a very low noise voltage and power supply rejection BIAS source designed

for biasing an electret condenser microphone cartridges. The BIAS output is typically set at

determined by the internal resistance 100

Ω (for detailed load regulation curves see Figure 6).

Figure 31. Lower cut-off frequency vs.

input capacitors

Figure 32. Lower cut-off frequency vs.

output capacitors

C

in

1

2

π F

CL

100

3

×10

⋅⋅

----------------------------------------------

=

C

out

1

2

π F

CL

R

ou t

⋅⋅

-------------------------------------

=

110

100

10

100

1000

Typical Zin

ZinMAX

Cin (nF)

ZinMIN

1

10

100

1000

10

100

1000

Rout=10k

Ω

Cout (nF)

Rout=100k

Ω