Datasheet

Product data sheet Rev. 03 — 20 March 2008 19 of 107

NXP Semiconductors

TEF6901A

Integrated car radio

The indicated amplitude levels are approximate values.

In the case of FM radio, carrier modulation is measured (MPX FM deviation). Timing is

ﬁxed with fast 30 ms release time. Depending upon reception conditions and internal

offsets small modulation levels may be indicated as MOD[4:0] = 0 0000b. After AF update

sampling the MOD read value is held (indicated by IFCM = 10) for easy I

C-bus read-out.

The MOD detector remains active in the background. The MOD data hold is released after

C-bus read.

In the case of AM radio, carrier modulation is measured (AM). Timing is ﬁxed with fast

30 ms release time. Modulation may exceed 100 % in cases of special modulation

schemes as used by some stations. After AF update sampling, the MOD read value is

held (indicated by IFCM = 10) for easy I

C-bus read-out. The MOD detector remains

active in the background. The MOD data hold is released after I

C-bus read.

With external source selection and VU-meter mode disabled (AVUM = 0 and COMP = 0)

FM or AM modulation is indicated equal to radio mode.

With external source selection and VU-meter mode enabled (AVUM=1orCOMP = 1) the

audio input level of the external source is indicated (i.e. the audio level as found on the line

input pins). For stereo signals left and right channels are combined for MOD read

(0.5 × L + 0.5 × R). VU-meter timing is deﬁned by setting HTC. For AVUM control see

subaddress 17h; see Table 97. In case of AF update sampling the AM or FM modulation

value is indicated with data hold (indicated by IFCM = 10) for easy I

C-bus read-out. The

MOD data hold is released after I

C-bus read and VU-meter indication continues.

0 1 1 0 1 47 kHz 63 % −4 dB 0.63 V

0 1 1 1 0 60 kHz 80 % −2 dB 0.8 V

0 1 1 1 1 75 kHz 100 % 0 dB 1 V

1 0 0 0 0 95 kHz 125 % 2 dB 1.25 V

1 0 0 0 1 120 kHz 160 % 4 dB 1.6 V

1 0 0 1 0 150 kHz 200 % 6 dB 2 V

10011- - - -

:::::: : : :

11110- - - -

1 1 1 1 1 offset

detection

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Table 15. MOD detector

…continued

MOD4 MOD3 MOD2 MOD1 MOD0 FM radio ∆f AM radio m VU External source