The TDA7850 Audio Chip: An In-Depth Technical Dive
The TDA7850 audio chip is a powerhouse component found in many Android headunits and other audio devices. It’s known for its high-quality sound reproduction and robust performance, making it a favourite among manufacturers and audiophiles alike. In this blog post, we’ll take a detailed look at the TDA7850, exploring its specifications, workings, and applications. Whether you’re a technical expert or a curious reader, this guide will provide you with a comprehensive understanding of this remarkable audio chip.
Introduction to the TDA7850
The TDA7850 is an integrated circuit (IC) designed by STMicroelectronics. It functions as a quad bridge amplifier, meaning it can drive four speakers simultaneously. This chip is widely used in car audio systems, including Android head units, due to its ability to deliver high-quality audio performance and robust power output.
Key Specifications of the TDA7850
Let’s start by listing the key specifications of the TDA7850. These will give you a snapshot of what this chip can do:
- Output Power: 4 x 50W
- Operating Voltage Range: 8V to 18V
- Distortion (THD): 0.015%
- Signal-to-Noise Ratio (SNR): 100dB
- Frequency Response: 20Hz to 20kHz
- Operating Temperature Range: -40°C to +85°C
- Mute and Standby Functions
- Diagnostic Facilities: Including short circuit and thermal protection
- High Output Power Capability: Operates at 2Ω loads
Understanding the Specifications
Output Power
The TDA7850 delivers an impressive 4 x 50W output power. This means it can drive four speakers, each with up to 50 watts of power, making it ideal for creating a powerful and immersive audio experience in your car. High output power ensures that your audio remains clear and loud even at higher volumes.
Operating Voltage Range
The chip operates within a voltage range of 8V to 18V. This range is suitable for automotive applications, where the voltage can fluctuate due to various electrical loads in the vehicle. The ability to operate within this range ensures stable performance under different conditions.
Total Harmonic Distortion (THD)
The THD of the TDA7850 is an incredibly low 0.015%. THD measures the distortion introduced by the amplifier; a lower percentage indicates cleaner and more accurate sound reproduction. This low THD means the TDA7850 can deliver high-fidelity audio without introducing noticeable distortion.
Signal-to-Noise Ratio (SNR)
With an SNR of 100dB, the TDA7850 ensures that the audio signal is much stronger than the background noise. A higher SNR means less background noise and clearer sound, which is particularly important in a car environment where external noise can be significant.
Frequency Response
The frequency response of 20Hz to 20kHz covers the entire range of human hearing. This wide frequency response ensures that the TDA7850 can accurately reproduce both deep bass and high treble sounds, providing a full and balanced audio experience.
Operating Temperature Range
The chip operates reliably within a temperature range of -40°C to +85°C, making it suitable for use in various climates and ensuring durability and reliability in automotive environments where temperatures can vary widely.
Special Features of the TDA7850
Mute and Standby Functions
The TDA7850 includes mute and standby functions, allowing for flexible control over the audio system. The mute function can silence the audio output without turning off the amplifier, while the standby function reduces power consumption when the audio system is not in use.
Diagnostic Facilities
The chip comes with built-in diagnostic facilities, including protection against short circuits and thermal overload. These features help prevent damage to the chip and connected speakers, ensuring longevity and reliability.
How the TDA7850 Works
The TDA7850 functions as a class AB amplifier, a type of amplifier that offers a good balance between efficiency and sound quality. Here’s a simplified explanation of how it works:
- Input Stage: The audio signal enters the TDA7850 through the input stage, where it is prepared for amplification.
- Voltage Amplification: The input signal is then passed to the voltage amplification stage, where it is increased to a level suitable for driving the output stage.
- Current Amplification: In the output stage, the signal is further amplified to a level that can drive the connected speakers.
- Output: The amplified audio signal is sent directly to the speakers, producing sound.
The TDA7850’s class AB design ensures high-quality sound reproduction with minimal distortion and good efficiency, making it a popular choice for high-performance audio systems.
Connection diagram of the TDA7850
IN1, IN2, IN3 and IN4 are the 4 inputs, which correspond with the 4 amplified speaker outputs OUT1, OUT2, OUT3 and OUT4. These 4 inputs/outputs relate to the front left, front right, rear left anf rear right speakers.
- ST-BY is the standby enable level input
- MUTE is the mute input signal line
- S-GND is the signal ground.
TDA7850 Block Diagram
Applications of the TDA7850
While the TDA7850 is commonly found in Android head units, it is also used in various other audio applications:
- Car Audio Systems: Beyond Android head units, the TDA7850 is used in traditional car stereos and aftermarket car audio amplifiers.
- Home Audio Systems: Some high-end home audio systems and amplifiers use the TDA7850 for its superior sound quality.
- Professional Audio Equipment: The chip is also found in professional audio equipment where high power and low distortion are critical.
Conclusion
The TDA7850 audio chip is a versatile and powerful component that plays a crucial role in delivering high-quality sound in various audio systems, especially in automotive environments. Its impressive specifications, including high output power, low distortion, and wide frequency response, make it an ideal choice for anyone looking to enhance their audio experience. Whether you are a technical expert or a casual reader, understanding the TDA7850’s capabilities and applications can help you appreciate the technology behind the exceptional sound quality in many modern audio devices.
By choosing systems that incorporate the TDA7850, you are investing in a proven solution that delivers reliability, performance, and exceptional audio clarity. Whether in an Android head unit or any other audio setup, the TDA7850 continues to set the standard for high-quality audio amplification.
