TEF6894H/V3,518

Overview

The TEF6894H is a monolithic BiMOS integrated circuit designed as an AM/FM car radio signal processor. It integrates stereo decoding, weak signal processing, and ignition noise blanking for both AM and FM bands. The device includes an input selector with four sources, tone/volume control, and a beep generator. It operates on an 8 V to 9 V supply voltage within an ambient temperature range of -40°C to +85°C. Communication is managed via a Fast mode 400 kHz I2C-bus interface. The component is housed in a 44-lead QFP package (10x10 mm) and requires only external coupling capacitors for signal inputs and outputs.

Feature Summary

• Integrated FM/AM noise blanker and weak signal processing with soft mute, stereo blend, and High Cut Control (HCC).
• FM stereo decoder with pilot cancellation, IF roll-off correction, and selectable 50/75 μs de-emphasis.
• Audio tone and volume control including loudness, treble (+/-14 dB), bass (+/-14 dB), fader, and balance.
• Input selector supporting two external stereo inputs (CD, TAPE), one mono input (PHONE), and internal AM/FM audio.

Applications

• Car radio integrated signal processors
• Automotive audio systems requiring AM/FM tuning and post-processing

Procurement Notes

Verify the specific ordering suffix against the manufacturer's current documentation to ensure compatibility with required packaging formats such as Tape & Reel or tube configurations. Confirm that the 44-QFP package dimensions align with the target Printed-Circuit Board footprint constraints before finalizing procurement orders.

Selection Notes

Select this component when a single-chip solution for AM/FM signal processing, stereo decoding, and audio tone control is required. Ensure the system design accommodates the 8 V to 9 V supply voltage requirement and utilizes an I2C bus operating at logic levels between 2.5 V and 5 V for controller interfacing.

Part Context

Originally manufactured by Philips Semiconductors, the TEF6894H is part of NXP's portfolio of automotive radio solutions. It serves as a specialized signal processor often paired with tuner ICs from the TEA684x family to provide complete radio reception and audio enhancement capabilities for vehicle infotainment architectures.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Verify pin-to-pin compatibility and functional equivalence with other NXP TEF series processors if considering alternative components for existing designs.

FAQ

How does the TEF6894H handle weak FM signals?

It uses detectors for RF level, Ultrasonic Noise (USN), and Wideband AM (WAM) information to generate control signals for soft mute, stereo blend, and High Cut Control (HCC).

What is the function of the gated I2C-bus loop through?

The gated I2C-bus loop allows connection to a tuner IC, easing PCB layout by reducing crosstalk and allowing mixed bus speeds while maintaining low bus load.

Can the de-emphasis time constant be changed dynamically?

Yes, the de-emphasis can be selected between 50 μs and 75 μs via the I2C-bus interface.