TEA2025D datasheet(5/9 Pages) STMICROELECTRONICS

5 / 9 page

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

The voltage gain is determined by on-chip resis-

tors R1 and R2 together with the external RfC1

series connected between pin 6 (11) and ground.

The frequency response is given approximated

by:

VOUT

VIN

+ R2 +

JWC1

With Rf=0, C1=100 uF, the gain results 46 dB

with pole at f=32 Hz.

THE purpose of Rf is to reduce the gain. It is rec-

ommended to not reduce it under 36 dB.

BRIDGE MODE

The bridge configuration is realized very easily

thanks to an internal voltage divider which pro-

vides (at pin 1) the CH 1 output signal after reduc-

tion. 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:

VOUT

VIN

+R2 +

JWC1

(1+

+R4+

JWC1

)

and with the suggested values (C1 = C2 = 100

µF,

Rf= 0) means:

Gv = 52 dB

with first pole at f = 32 Hz

Output Capacitors.

The low cut off frequency due to output capacitor

depending on the load is given by:

ΠCOUT • RL

with COUT 470

µF and RL = 4 ohm it means FL =

80 Hz.

Pop Noise

Most amplifiers similar to TEA 2025B need exter-

nal resistors between DC outputs and ground in

order to optimize the pop on/off performance and

crossover distortion.

The TEA 2025B solution allows to save compo-

nents because of such resistors (800 ohm)are in-

cluded into the chip.

Figure 7

Figure 8

Figure 9

TEA2025B - TEA2025D

5/9

TEA2025D Datasheet(PDF) 5 Page - STMicroelectronics

TEA2025D Datasheet(HTML) 5 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9

Datasheet Download

Link URL