Overview
The TDA7385 is an AB class audio power amplifier designed by STMicroelectronics, specifically tailored for high-end car radio applications. It is packaged in the Flexiwatt 25 format, which allows for a compact design due to the reduced number of external components required. The amplifier features a fully complementary PNP/NPN configuration, enabling a rail-to-rail output voltage swing without the need for bootstrap capacitors. This design ensures high output power capability and low distortion, making it ideal for automotive audio systems.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Operating Supply Voltage (VS) | 18 | V |
| DC Supply Voltage (VS DC) | 28 | V |
| Peak Supply Voltage (VS pk) | 50 | V (t = 50 ms) |
| Output Peak Current (IO) | 4.5 (repetitive), 5.5 (non-repetitive) | A |
| Power Dissipation (Ptot) | 80 | W (Tcase = 70 °C) |
| Junction Temperature (Tj) | 150 | °C |
| Storage Temperature (Tstg) | -55 to 150 | °C |
| Output Power (Po) @ 4 Ω, THD = 10% | 23 W (VS = 14.4 V), 42 W (VS = 15.2 V) | W |
| Distortion (THD) @ Po = 4 W | 0.04 % | % |
| Quiescent Current (Iq1) | 180 - 300 | mA |
| Voltage Gain (Gv) | 25 - 27 | dB |
| Input Impedance (Ri) | 70 - 100 | kΩ |
Key Features
- High Output Power Capability: Up to 4 x 42 W / 4 Ω max.
- Clipping Detector: Simplifies gain compression operations and signals clipping events.
- Low Distortion: Ensures high-quality audio output.
- Low Output Noise: Minimizes noise in the audio signal.
- Standby and Mute Functions: Allows for power saving and silent operation.
- Diagnostics Facility: Detects clipping, overheating, output misconnections, and other faults.
- Protections: Includes protections against output short circuits, overrating chip temperature, load dump voltage, and ESD.
- Low External Component Count: Internally fixed gain and no external compensation or bootstrap capacitors required.
Applications
The TDA7385 is primarily designed for high-end car radio applications, making it an ideal choice for automotive audio systems. Its features such as high output power, low distortion, and comprehensive diagnostics make it suitable for a variety of automotive audio installations.
Q & A
- What is the maximum output power of the TDA7385?
The TDA7385 can deliver up to 4 x 42 W of output power at 4 Ω load.
- What is the typical distortion level of the TDA7385?
The typical distortion level is 0.04% at an output power of 4 W.
- Does the TDA7385 have built-in protection features?
Yes, it includes protections against output short circuits, overrating chip temperature, load dump voltage, and ESD.
- How does the clipping detector work?
The clipping detector signals clipping events by outputting pulses synchronized with the clipping occurrences in the music program.
- What is the purpose of the diagnostics facility?
The diagnostics facility detects clipping, overheating, output misconnections, and other faults, providing diagnostic information through an open collector output.
- What is the recommended value for the SVR capacitor?
The minimum recommended value for the SVR capacitor is 10 µF.
- How does the standby function work?
The standby function allows the amplifier to enter a low power consumption state, with a standby current consumption of up to 15 µA.
- What is the input impedance of the TDA7385?
The input impedance is typically between 70 kΩ and 100 kΩ.
- Is the TDA7385 stable without external compensation?
Yes, the TDA7385 is intrinsically stable with no need for external compensations such as output R-C cells.
- What is the thermal resistance junction-to-case of the TDA7385?
The thermal resistance junction-to-case is 1 °C/W.
