TS472

Application Information

15/20

2.

To 20dB by applying

TS472 itself on BIAS pin.

Following

4.6

Wake-up time

When the standby is released to put the device ON, a signal appears on the output a few

microseconds later, and the bypass capacitor Cb is charged in a few milliseconds. As Cb is

directly linked to the bias of the amplifier, the bias will not work properly until the Cb voltage is

correct.

In the typical application, when a biased microphone is connected to the differential input via

the input capacitors (Cin), (and the output signal is in line with the specification), the wake-up

time will depend upon the values of the input capacitors Cin and the gain. When gain is lower

than 0dB, the wake-up time is determined only by the bypass capacitor Cb, as described

above. For a gain>0dB, see

Figure 36

Figure 35. Gain vs. gain select voltage

Figure 36. Wake-up time in the typical application vs. input capacitors

0

0.2

0.4

0.6

0.8

4

5

-80

-60

-40

-20

0

20

40

Tamb=25

°C

V

GS

20

40

60

80

100

0

10

20

30

40

50

60

Gain=20dB

Tamb = 25°C

Vcc=3V

Cb=1

µF

Input capacitors C

IN

(nF)

Maximum Gain