TEA2025A

LINEAR INTEGRATED CIRCUIT

UNISONICTECHNOLOGIESCO.,LTD

5 of 8

www.unisonic.com.tw

QW-R107-012.C

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APPLICATION INFORMATION

Input Capacitor

Input capacitor is PNP type allowing source to be referenced to ground. In this way no input coupling capacitor is

required. However, a series capacitor (0.22 uF)to the input side can be useful in case of noise due to variable

resistor contact.

Bootstrap

The bootstrap connection allows to increase the output swing. The suggested value for the bootstrap capacitors

(100uF) avoids a reduction of the output signal also at low frequencies and low supply voltages.

Voltage Gain Adjust

STEREO MODE (Figure 1)

The voltage gain is determined by on-chip resistors R1 and R2 together with the external RfC1 series connected

between pin 6 (11) and ground. The frequency response is given approximated by:

The purpose of Rf is to reduce the gain. It is recommended to not reduce it under 36 dB.

C1

6 (11)

2 (15)

Figure 1

BRIDGE MODE (Figure 2)

The bridge configuration is realized very easily thanks to an internal voltage divider which provides (at pin 1) the

CH 1 output signal after reduction. It is enough to connect pin 6 (inverting input of CH 2) with a capacitor to pin 1 and

to connect to ground the pin 7.

The total gain of the bridge is given by: