TEF6903AH/V5S,518 NXP Semiconductors, TEF6903AH/V5S,518 Datasheet - Page 11

• Manufacturer Part Number: TEF6903AH/V5S,518
• Description: IC CAR RADIO SGL CHIP CIRC 80QFP
• Manufacturer: NXP Semiconductors

Specifications of TEF6903AH/V5S,518

• Modulation Or Protocol: AM, FM, WB
• Applications: AM/FM Radio Receiver
• Current - Receiving: 102mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 8 V ~ 9 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Frequency: -
• Sensitivity: -
• Memory Size: -
• Data Rate - Maximum: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 935288823518

NXP Semiconductors
TEF6904A_3
Product data sheet
7.22 FM and AM AF noise blanker
7.23 Fixed high cut and high cut control
7.24 De-emphasis
7.25 Weak signal processing
7.26 Audio step interpolation
7.27 Source selector
The FM or AM tuner operation selects between two noise blanker operations optimized for
FM or AM ignition noise suppression.
In FM mode the noise blanker operates as a modified sample and hold circuit with
ultrasonic noise detection on MPX and detection of noise spikes on level.
In AM mode the audio signal is muted during the interference pulse triggered by slew-rate
detection of the audio signal.
The high cut part is a low-pass filter circuit with seven bandwidth settings. The cut-off
frequencies of the filter curves can be selected to match different application requirements
(fixed high cut).
The high cut circuit also provides a dynamic control of the filter response, the High Cut
Control (HCC). This function is controlled by the HCC signal from the weak signal
processing.
The signal passes the low-pass filter de-emphasis block and is then fed to the source
selector. The de-emphasis time constant can be selected between the standards of 50 s
and 75 s.
The weak signal processing block detects quality degradations in the incoming signal and
controls the processing of the audio signal accordingly. The weak signal processing block
has three different quality criteria: The average value of the level voltage, AM components
on the level voltage (WAM = wideband AM) and high frequency components in the MPX
signal (USN = ultrasonic noise).
In the weak signal processing block these signals are combined in specific ways and used
for the generation of control signals for soft mute, stereo blend (SNC = stereo noise
control) and HCC. Detector time constants of soft mute, HCC and SNC can be selected
independently.
In AM mode, soft mute and HCC are controlled by the average value of the level voltage.
The tone/volume blocks of source selector, volume/balance, bass/loudness, fader and
output mute include the Audio Step Interpolation (ASI) function. This minimizes audible
pops by smoothing the transitions in the audio signal during the switching of the controls.
The source selector selects one out of several input sources:
•
•
One internal stereo signal (AM/FM tuner)
Eight input pins allow many combinations of external sources by means of flexible
input selection
Rev. 03 — 20 March 2008
TEF6904A
Integrated car radio
© NXP B.V. 2008. All rights reserved.
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