TDA1904

Overview

The TDA1904 is a monolithic Class AB audio power amplifier in a Powerdip package. It operates within a supply voltage range of 4V to 20V and delivers up to 4W output power into a 4Ω load at 14V. The device features high peak output current capability, reaching 2A repetitive and 2.5A non-repetitive. Key electrical characteristics include a quiescent drain current of approximately 10mA at 14V, a closed-loop voltage gain of 40dB, and a small-signal bandwidth from 40Hz to 40kHz. It incorporates thermal shutdown protection and offers low noise performance.

Feature Summary

• Integrated thermal limiting circuit prevents damage from overload or excessive ambient temperature by reducing power dissipation when junction temperature reaches 150°C.
• High output current capability supports driving low impedance loads effectively.
• Low noise design ensures high-quality audio reproduction with minimal input noise.
• High supply voltage rejection ratio maintains stable operation against supply ripple.

Applications

• Low-frequency power amplification for portable radio sets
• Audio amplification in portable TV sets

Procurement Notes

Verify component status as the datasheet indicates this product is obsolete. Confirm availability through authorized distributors or secondary market suppliers. Ensure the Powerdip 16-pin package matches the target PCB footprint. Review thermal management requirements carefully, as the device relies on specific heatsinking configurations via its frame pins for adequate heat dissipation during operation.

Selection Notes

Select this component for applications requiring a simple, single-supply Class AB amplifier solution. It is suitable for designs operating between 4V and 20V where moderate power output into 4Ω loads is sufficient. Consider the thermal resistance characteristics and the necessity of external bootstrap and decoupling capacitors for optimal performance and stability under varying supply conditions.

Part Context

The TDA1904 belongs to STMicroelectronics' legacy audio amplifier portfolio. It is designed as a low-cost, robust solution for consumer electronics. The device utilizes a Powerdip package that integrates thermal dissipation paths through multiple ground pins, simplifying board-level thermal management compared to standard DIP packages without exposed pads.

Replacement Considerations

As the TDA1904 is marked obsolete, direct substitutes may be limited. Evaluate other STMicroelectronics Class AB audio amplifiers in similar packages or pin-compatible alternatives from other manufacturers. Verify that any replacement meets the required supply voltage range, output power specifications, and thermal performance characteristics for the intended application.

FAQ

What is the purpose of resistor R4 in the application circuit?

Resistor R4 (68Ω) is necessary only when the supply voltage is less than 6V. It increases the output swing to obtain maximum output power under low supply voltage conditions.

How does the thermal shutdown feature protect the device?

If the junction temperature increases up to 150°C due to overload or high ambient temperature, the thermal shut-down circuit reduces power dissipation and current consumption, preventing device damage.