Datasheet

TEF6901A_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 March 2008 12 of 107
NXP Semiconductors
TEF6901A
Integrated car radio
7.31 Bass
The bass tone control stage controls the low audio frequencies with a modified shelve
curve response. The control range is between +14 dB and −14 dB in steps of 2 dB. Four
different filter cut-off frequencies can be selected.
7.32 Treble
The treble tone control stage controls the high audio frequencies with a shelve curve
response. The control range is between +14 dB and −14 dB in steps of 2 dB. Four
different filter cut-off frequencies can be selected.
7.33 Loudness
An integrated loudness function can be activated which controls bass and treble in relation
to the user volume setting. The control range of the bass frequencies is limited to 20 dB
and the optional treble range to 4 dB. Different volume ranges can be selected for the
loudness control.
7.34 Fader
The fader is located at the end of the tone/volume chain. The balance between the front
and rear channel can be controlled by attenuation of either the front or the rear channel.
Control range is 0 dB to −64 dB with a step size of 1 dB. Optionally the fader attenuation
can be activated for front and rear channels together.
7.35 RDS/RBDS demodulator
The RDS demodulator recovers and regenerates the continuously transmitted RDS or
RBDS data stream that may be part of the FM MPX signal and provides the signals clock
(RDCL) and data (RDDA) for further processing by a hardware or software RDS decoder.
Unbuffered demodulator output and buffered 16-bit output mode are available. The output
modes are compatible with stand-alone demodulator devices as well as digital and analog
signal processor standards. In case of buffered output mode additional RDS Quality
(RDQ) demodulation quality information is available optional.
8. I
2
C-bus protocol
SDA and SCL HIGH and LOW internal thresholds are specified according to both 2.5 V
and 3.3 V I
2
C-bus, however also SDA and SCL signals froma5Vbusaresupported. The
maximum I
2
C-bus communication speed is 400 kbit/s in accordance with the I
2
C-bus fast
mode specification.
Fig 3. Write mode
ACK-s ACK-s
DATASLAVE ADDRESS W
data transferred
(n bytes + acknowledge)
001aad051
PS ACK-s
MSA