TDA7265 Characteristics, Technical Parameters, Pinout and Application
22 March 2024
Ⅲ. The technical parameters of TDA7265
Ⅴ. TDA7265 protection mechanism
Ⅶ. TDA7265 application circuit
Ⅷ. What are the common faults of TDA7265?
TDA7265 is a dual-channel audio power amplifier IC produced by ST, suitable for use as an audio power amplifier in TVs and Hi-Fi amplification equipment. The IC has an excellent output power performance of 25W per channel and a wide range of supply voltages from 5V to 25V. In addition, the TDA7265 is equipped with a mute function and a standby function, providing users with a more convenient operating experience. In terms of internal structure, the TDA7265 contains two audio power amplifier integrated circuits with the same function, as well as an over-current protection circuit and an over-heat protection circuit. These protection circuits can effectively prevent the circuit from being damaged under abnormal conditions, improving the stability and reliability of the entire system. Meanwhile, the TDA7265 is also equipped with some other auxiliary function circuits to meet the needs of different application scenarios.
Replacements and equivalents:
• LM1875
• TDA7263M
• TDA7269
• TDA7269A
As an excellent audio amplifier chip, TDA7265 has the following features:
• High input impedance: The input impedance of TDA7265 is up to 100kΩ, which has a small impact on the load of the signal source.
• Low voltage distortion: The voltage distortion of TDA7265 is less than 1mV, which ensures high fidelity transmission of audio signals.
• Single power supply: TDA7265 adopts single power supply, which simplifies the circuit design and improves the convenience of use.
• Built-in protection circuit: TDA7265 has built-in protection circuits for overheat, overcurrent and short circuit, which can provide comprehensive safety protection for the device.
• The manufacturer of TDA7265 is STMicroelectronics.
• Its output power is 25W.
• Its power consumption is 30W.
• It has a power supply rejection ratio of 60 dB.
• It adopts through-hole mounting method.
• Its power supply voltage is 5V to 25V.
• Its operating temperature is -20°C to 85°C.
• It has a gain of 80 dB.
• TDA7265 belongs to the category of audio amplifiers.
• The TDA7265 has an input compensation voltage of 20 mV and an input bias current of 500nA.
• The length of the TDA7265 is 19.6 mm, the width is 5 mm, and the height is 10.7 mm.
• TDA7265 has 11 pins and comes in Multiwatt-11 package and tube packaging.
Pin 1 (-Vs): Negative power supply is connected to this pin in dual supply mode operation of the chip.
Pin 2 (OUTPUT (1)): Amplified output of channel A is provided at this pin.
Pin 3 (+Vs): Positive power supply is connected at this pin.
Pin 4 (OUTPUT (2)): Amplified output of the channel B is provided at this pin.
Pin 5 (MUTE): This pin is pulled low to disabled the audio output.
Pin 6 (-Vs): Negative power supply is connected to this pin in dual supply mode operation of the chip.
Pin 7 (IN+(2)): Non-inverting input of channel B amplifier in the chip
Pin 8 (IN-(2)): Inverting input of channel B amplifier in the chip
Pin 9 (GND): This pin is connected to the ground.
Pin 10 (IN-(1)): Inverting input of channel A amplifier in the chip
Pin 11 (IN+(1)): Non-inverting input of channel A amplifier in the chip
1. Supply voltage protection
The stability of supply voltage is crucial for the normal operation of TDA7265. Therefore, this chip is especially equipped with a supply voltage protection function. Once the power supply voltage is too high or too low, the protection function will be activated immediately to prevent the chip from being damaged due to the abnormal power supply voltage by adjusting the chip's working status or interrupting the power supply.
2. Overload protection
Overload protection is a key protection mechanism of TDA7265. When the input signal exceeds the processing range of the chip or the load impedance is not matched, the overload protection will be activated quickly. It reduces the output power or interrupts the output to prevent the chip from excessive current or voltage impact. This protection mechanism effectively prevents the chip from being damaged due to overload and ensures the stable operation of the audio system.
3. Thermal protection
TDA7265 also has overheating protection. Under long time high power output or poor heat dissipation conditions, the chip may overheat. Once the chip temperature exceeds the safe range, the overheating protection mechanism will be automatically triggered to reduce the output power or interrupt the power supply to avoid damage to the chip due to overheating. This protection mechanism ensures the reliability of the chip in harsh environments and extends its service life.
4. Start-up delay protection
TDA7265 also has a start-up delay protection mechanism. When the chip is powered on and started, the output may be unstable due to capacitor charging and circuit stabilization. The start-up delay protection can ensure that the internal circuit of the chip is stabilized before the output of audio signals, to avoid the abnormal output of the start-up moment on the speakers or other equipment caused by the impact.
5. Short circuit protection
Short-circuit protection is a protection mechanism designed by TDA7265 for the abnormal situation that may occur at the output. When a short-circuit occurs at the output, the short-circuit protection mechanism will immediately cut off the output to prevent excessive current from damaging the chip. This fast response protection helps protect the chip from potential risks associated with short circuits.
Listed below are some common applications of TDA7265:
• Computer speakers
• Multimedia player
• Car audio system
• Headphone amplifier
• TV/monitor audio
1. TDA7265 single power supply application circuit diagram (OTL circuit)
2. TDA7265 bridge application circuit diagram (BTL circuit)
1. Input signal problems: Abnormalities in the input signal may mean that the amplitude, frequency or phase of the signal deviates significantly from the normal state. This may be due to a problem with the signal source, such as a malfunction in the source itself, or interference in the transmission line. When the TDA7265 receives such an abnormal signal, it may not be able to amplify and process it correctly, resulting in impaired or distorted sound quality at the output.
2. Power supply problems: There are many voltage-sensitive electronic components inside the audio power amplifier, such as capacitors, transistors and resistors. When the supply voltage is unstable, these components may not work properly and may even be damaged. For example, transistors may burn out due to excessive voltage and capacitors may fail due to voltage fluctuations. All these failures will directly affect the performance and stability of the TDA7265, resulting in its inability to output high-quality audio signals.
3. Overheating: In the working process, the chip will generate a certain amount of heat. If the heat dissipation design is not appropriate or the ambient temperature is too high, it may cause the chip temperature to be too high. Prolonged high-temperature operation will accelerate the aging of the components inside the chip, and may even directly burn some key components.
4. Short-circuit protection trigger: If the load is too heavy, i.e., the power required by the connected speakers or other devices exceeds the capacity of TDA7265, the short-circuit protection function will be triggered. In this case, the chip will automatically adjust its operating state or disconnect the power supply completely to prevent irreversible damage to internal components caused by overload.
5. Overload protection trigger: TDA7265 has a built-in overload protection mechanism. When the signal input to TDA7265 is too large, beyond its normal processing range, the overload protection mechanism will be quickly activated. At this time, the chip is able to quickly detect the abnormality of the input signal and automatically adjust its working state, thus avoiding damage to the internal circuitry caused by the oversized signal. Such adjustments may result in a sudden interruption of the output sound or a significant reduction in output power, but these are designed to ensure that the entire audio system is protected from the potential damage of overload.
Frequently Asked Questions
1. What does the stand-by mode in TDA7265 do?
The stand-by mode in TDA7265 allows the amplifier to enter a low-power state when not in use, reducing power consumption.
2. How many watts is TDA7265?
TDA7265 is a 25W + 25W stereo amplifier with mute and standby. It is a class AB dual Audio power amplifier. It is specially designed for high-quality sound applications such as Hi-Fi music centres and stereo TV sets.
3. What is the output of TDA7265 IC?
This IC can deliver up to 50W (25+25) of output power, so you can run two 4Ω speakers at 25W each for stereo audio quality. It is specifically designed for high-quality sound applications such as music centers and stereo TV sets.
4. How do I unmute my TDA7265?
If you have no need to control it just connect it (5) to ground through a 1k to 15k resistor and the amp will always be on (out of standby and unmuted). You may get some noise out of the speakers as the power supply comes on.
