TDA7338D

Encoders, Decoders, Converters Overview

The TDA7338D is a monolithic integrated stereo decoder with noise blanking for FM car radio applications, manufactured by STMicroelectronics. It utilizes BICMOS technology and a switched capacitor concept to realize the 19KHz Notch Filter, PLL Filter, and Phase Filter on-chip. The device operates at a supply voltage of 7.5V to 10.2V (typical 9V) with a typical supply current of 10mA. Key electrical characteristics include a gain of 9.5dB, channel separation of 45dB, and total harmonic distortion of 0.3%. It features an internally fixed oscillator frequency of 456kHz when used with a Murata CSB456F11 resonator. The component is housed in an SO20 package.

Encoders, Decoders, Converters Feature Summary

• Integrated 19KHz SC notch filter for pilot cancellation
• Automatic pilot dependent mono/stereo switching
• Noise blanking with programmable threshold
• High cut control and stereo blend functions

Encoders, Decoders, Converters Applications

• FM car radio stereo decoders
• Automotive audio systems requiring noise suppression
• Monolithic integrated circuit designs for broadcast receivers

Encoders, Decoders, Converters Procurement Notes

Verify component status as obsolete before procurement planning. Confirm availability through authorized distributors or secondary market suppliers. Ensure compatibility with existing design infrastructure if replacing active components. Review datasheet revision history for any specification updates prior to finalizing orders.

Encoders, Decoders, Converters Selection Notes

Select this component for applications requiring a complete stereo decoding solution with integrated noise blanking. Consider the requirement for an external ceramic resonator operating at 456kHz. Evaluate the need for specific de-emphasis time constants and high-cut control adjustments based on the target RF front-end signal strength characteristics.

Encoders, Decoders, Converters Part Context

The TDA7338 series represents a specialized class of FM stereo decoders designed specifically for automotive environments. It integrates complex signal processing functions typically requiring multiple discrete components into a single BICMOS chip. This integration reduces board space and simplifies the design of high-performance car radio systems from that era.

Encoders, Decoders, Converters Replacement Considerations

As the TDA7338D is listed as an obsolete product, direct pin-to-pin replacements may not be readily available from the original manufacturer. Engineers must evaluate modern FM stereo decoder ICs that offer comparable noise blanking and pilot detection capabilities, ensuring interface compatibility with existing tuner modules.

Encoders, Decoders, Converters FAQ

How is the VCO frequency determined?

The internal oscillator runs at 456kHz when paired with a specific external ceramic resonator, such as the Murata CSB456F11.

What is the function of Pin 7 and Pin 8?

Pin 7 activates the VCO-OFF function when pulled to ground, while Pin 8 activates the MUTE function when pulled to ground.

How does the noise blanker handle interference?

It detects spikes via a highpass-filtered path and switches off the output for approximately 40µs to cancel ignition or motor interference.