TEA6320T/V1,512

Overview

The TEA6320T is a sound fader control circuit designed for I2C-bus controlled stereo preamplifier applications, primarily in car radio and hi-fi systems. It integrates source selection, volume, balance, fader, bass, treble, and loudness controls within a single 32-SO package. The device operates on a supply voltage of 7.5V to 9.5V with a typical current draw of 26 mA. Key electrical specifications include a maximum voltage gain of +20 dB, a signal-plus-noise ratio of 105 dB, and channel separation of 96 dB. It supports four stereo inputs and one mono input, featuring fast mute capabilities via I2C or hardware pin.

Feature Summary

• Integrated I2C-bus control for all functions including volume, balance, fader, bass, treble, and source selection.
• Automatic loudness characteristic control linked to volume settings, providing up to 17 dB bass boost at 40 Hz.
• Dual-stage volume control: Volume I (+20 dB to -31 dB) and Volume II (0 dB to -55 dB) for precise attenuation.
• Three mute modes: zero-crossing mute via I2C, fast mute via MUTE pin, and general mute via I2C.

Applications

• Car radio pre-amplifiers
• Hi-fi sound system controllers
• Audio source selector circuits

Procurement Notes

Verify the obsolete status of this component before design finalization. Confirm that the 32-SOIC package dimensions match the target PCB footprint. Ensure the I2C bus voltage levels are compatible with the host microcontroller, as the device operates at 7.5V to 9.5V supply. Check for available alternative components if long-term supply is required.

Selection Notes

Select this IC when a complete analog audio front-end with digital control is needed. It requires external capacitors for bass/treble filtering and mute timing. The supply voltage range (7.5V-9.5V) suits automotive 12V systems. Consider the 105 dB SNR and 96 dB channel separation for high-fidelity requirements. External equalizer interfaces are available via specific pins if bypassing internal tone controls.

Part Context

The TEA6320T belongs to NXP's (formerly Philips) legacy line of sound fader control circuits. It is functionally similar to the TEA6321, TEA6322, and TEA6323 series, which offer comparable audio processing features in various packages. These devices were widely used in automotive audio systems from the 1990s.

Replacement Considerations

Publicly confirmed substitute part numbers are not provided in the verified documentation. Designers should consult NXP for current alternatives or evaluate generic I2C-controlled audio preamps if the TEA6320T is unavailable.

FAQ

How does the loudness control interact with volume settings?

The loudness characteristic is automatically controlled in combination with the volume setting. The filter characteristic increases linearly from +20 dB down to -12 dB volume setting, providing maximum bass and treble boost at lower volumes.

What are the available mute modes?

The TEA6320T offers three mute modes: zero-crossing mute via I2C (prevents popping), fast mute via the MUTE pin (hardware), and general mute via I2C. The zero-crossing mute can be delayed by an external capacitor to limit switching time.

Can the internal bass and treble controls be bypassed?

Yes. The bass and treble control functions can be switched off via the I2C-bus. In this mode, the internal signal flow is disconnected, and pins B2L/B2R become outputs while TL/TR become inputs for connecting an external equalizer.