Datasheet

TEF6901A_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 March 2008 85 of 107
NXP Semiconductors
TEF6901A
Integrated car radio
12.2 Dynamic characteristics of the sound processor
Fig 40. AM AGC circuit
008aaa004
JFET
LNA
CASCODE
AGC
RF
FILTER
AGC
THRESHOLD
X
AM
MIXER1
X
AM
MIXER2
detector A
enable 1 mA
pin diode current
(FM mode)
AGCSW
reduce cascode
AGC control range
KAGC
detector B
3228, 292723, 242119159
pin
diode
IAMAGCTRFAGC
RFIN
AGC threshold
AGC[1:0]
VAMCAS
18
VAMCASFB AMMIX1IN
AMMIX2OUT1,
AMMIX2OUT2
TEF6901AH
AMIF2IN
MIX1OUT1,
MIX1OUT2 IF1IN
Table 111. Dynamic characteristics of the sound processor
V
CC
= 8.5 V; T
amb
=25 ° C; see Figure 43; all AC values are given in RMS; treble: 10 kHz filter frequency; treble = 0 dB;
bass: 60 Hz filter frequency; bass = 0 dB; f
audio
= 1 kHz; G
vol
= 0 dB; G
fader
= 0 dB; loudness off; standard output gain
(byte OUTPUT; bit OUTA = 0); R
L
= 10 k Ω ; C
L
= 1 nF; unless otherwise specified.
Symbol Parameter Conditions Min Typ Max Unit
Stereo decoder and AM path
V
o(FM)
FM mono output voltage
on pins LFOUT and
RFOUT
f
MPXAMOUT
= 1 kHz;
30 % FM modulation without
pilot
- 330 - mV
V
o(AM)
AM output voltage on
pins LFOUT and RFOUT
f
AM
= 1 kHz;
30 % AM modulation
- 365 - mV
α
cs
channel separation f
FMMPX
= 1 kHz 40 - - dB
g
f(L-R)
stereo adjust for fine
adjustment of separation
measure 1 kHz level for L − R
modulation; compare to 1 kHz
level for L + R modulation
CSA[3:0] = 0000 - 0 - dB
CSA[3:0] = 0001 - 0.2 - dB
:-:-dB
CSA[3:0] = 1110 - 2.8 - dB
CSA[3:0] = 1111 - 3.0 - dB