UNISONIC TECHNOLOGIES CO.,LTD.

TEA2025A LINEAR INTEGRATED CIRCUIT

STEREO AUDIO AMPLIFIER

„ DESCRIPTION
The UTC TEA2025A is a monolithic integrated circuit,
consisting of a 2-channel power amplifier. It is suitable for stereo
and bridge amplifier application of radio cassette tape recorders.
„ FEATURES
* High output power
Stereo: Po=2.3W (Typ) at Vcc=9V, RL=4 Ω
Bridge: Po=4.7W (Typ) at Vcc=9V, RL=8Ω
* Low switching distortion at high frequency
* Small shock noise at the time of power on/off dur to a built-in
muting circuit
* Good ripple rejection due to a built-in ripple filter
* Good channel separation
* Soft tone at the time of output straiten
* Closed loop voltage gain fixed 45dB (Bridge: 51dB) but
availability with external resistor added
* Minimum number of external parts required
* Easy to design radiator fin
„ ORDERING INFORMATION
Order Number
Package Packing
Lead Free Halogen Free
TEA2025AL-D12-H-T TEA2025AG-D12-H-T DIP-12H Tube

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TEA2025A LINEAR INTEGRATED CIRCUIT
„ PIN CONFIGURATION

BTL OUT 1 12 VCC

OUT 2 2 11 OUT 1

B.S.2 3 10 B.S.1

NF2 4 9 NF1

IN 2 5 8 IN 1
DC 6 7 PRE GND

„ BLOCK DIAGRAM

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TEA2025A LINEAR INTEGRATED CIRCUIT
„ ABSOLUTE MAXIMUM RATINGS (TA=25°C, unless otherwise specified)
PARAMETER SYMBOL RATINGS UNIT
Supply Voltage VS 15 V
Power Dissipation PD 4 W
Operating Temperature TOPR -20~+70 °C
Storage Temperature TSTG -40~+150 °C
Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.
„ ELECTRICAL CHARACTERISTICS (TA=25°C, RG=600V, Stereo, unless otherwise specified.)
PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT
Operating Supply Voltage VCC 3 12 V
Quiescent Current ICC Vi=0, Stereo 40 50 mA
Stereo, Vi=-45dBm 43 45 47 dB
Closed Loop Voltage Gain AV
Bridge, Vi=-45dBm 49 51 53 dB
Channel Balance CB Stereo -1 0 +1 dB
Stereo, RL=4Ω, THD=10% 1.7 2.3 W
Output Power PO Stereo, RL=8Ω, THD=10% 1.3 W
Bridge, RL=8Ω, THD=10% 4.7 W
Stereo, Po=250mW, RL=4Ω 0.3 1.5 %
Total Harmonic Distortion THD
Bridge, Po=250mW, RL=4Ω 0.5 %
Input Resistance RI 21 30 KΩ
Stereo, Rg=0Ω, Vr=150mV,
Rijpple Rejection RR 40 46 dB
f=100Hz
Stereo, Rg=0Ω 1.5 3 mV
Output Noise Voltage VNO
Stereo, Rg=10KΩ 3 6 mV
Cross-Talk CT Stereo, Rg=10KΩ, Vo=0dBm 40 55 dB

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TEA2025A LINEAR INTEGRATED CIRCUIT
„ APPLICATION IN FORMATION
Stereo Amplifier

Bridge Amplifier

0.22μF C2 100µ/16V
INPUT +
+ C1
100µ/16V VCC
7 8 9 Fin 10 11 12 C4
+ +
C3 470µ/16V + C5
0.15µ 100µF
UTC TEA2025A RL

Fin C6
6 5 4 3 2 1 + 470µ/16V
C10 +
100µ/16V +
C8 +
100µ/16V C7
+ 0.15µ
C9 100µ/16V
Polyester film capacitor

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TEA2025A LINEAR INTEGRATED CIRCUIT
„ 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:

With Rf=0, C1=100μF, the gain results 46 dB with pole at f=32 Hz.
The purpose of Rf is to reduce the gain. It is recommended to not reduce it under 36 dB.

6 (11) R2
2 (15)

Rf
R1

C1

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:

and with the suggested values (C1 = C2 = 100 uF, Rf = 0) means: Gv = 52 dB with first pole at f = 32 Hz

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TEA2025A LINEAR INTEGRATED CIRCUIT
„ APPLICATION INFORMATION(Cont.)

IN

OUT OUT

R1 R1

R3

R2 R2

R4

Figure 2

Output Capacitors
The low cut off frequency due to output capacitor depending on the load is given by:

with COUT 470uF and RL = 4 ohm it means FL = 80Hz.

Pop Noise (Figure 3)

Most amplifiers similar to UTC TEA2025A need external resistors between DC outputs and ground in order to
optimize the pop on/off performance and crossover distortion.

OUT

800

Figure 3

The UTC TEA2025A solution allows to save components because of such resistors (800 ohm) are included into
the chip.

Stability
A good layout is recommended in order to avoid oscillations. Generally the designer must pay attention on the
following points:
- Short wires of components and short connections.
- No ground loops.
- Bypass of supply voltage with capacitors as nearest as possible to the supply I. C. pin. The low value (poliester)
capacitors must have good temperature and frequency characteristics.
- No sockets.
The heatsink can have a smaller factor of safety compared with that of a conventional circuit. There is no device
damage in the case of excessive junction temperature: all that happens is that PO (and therefore Ptot) and Id are
reduced.

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TEA2025A LINEAR INTEGRATED CIRCUIT
„ TYPICAL CHARACTERISTICS

UTC assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or
other parameters) listed in products specifications of any and all UTC products described or contained
herein. UTC products are not designed for use in life support appliances, devices or systems where
malfunction of these products can be reasonably expected to result in personal injury. Reproduction in
whole or in part is prohibited without the prior written consent of the copyright owner. The information
presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice.

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