TEA6825T PHILIPS [NXP Semiconductors], TEA6825T Datasheet - Page 30

• Manufacturer Part Number: TEA6825T
• Description: In Car Entertainment ICE car radio
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
IF-counter read out
IF-counter read out as a function of FM or AM position, counter window and prescaler setting
Note
1. In position FM with a prescaler ratio of 25, counter window of 40 ms and in position AM with 40 ms counter window
The IF-count windows are valid for a crystal oscillator frequency of 61.5 MHz.
The FM/AM switching is carried out by bit 0 of byte 2 of the received data of the IC.
The IF-counter operates continuously.
The IF-counter and window-counter will be reset when the I
changes in the latches for the IF-count, while reading this value. If the transmission to the front-end IC is disabled after
the synthesizer loop of the TEA6810T/TEA6811T front-end IC has locked for a new frequency, the IF-count will be
available after the set measuring time.
The IF-counter starts at 0. The IF-counter output are the 8 least significant bits of the counting result.
1998 Mar 24
FM
FM
FM
FM
AM
AM
FM/AM
In Car Entertainment (ICE) car radio
ambiguous counting results within the IF filter bandwidth are obtained. The counting range is 127 counts above and
127 counts below the nominal IF of 10.7 MHz for FM and 450 kHz for AM.
(1)
(1)
PRESCALER
RATIO
200
200
25
25
1
1
WINDOW
(ms)
40
40
40
4
4
4
10700
10700
10700
10700
(kHz)
450
450
f
IF
30
2
READ OUT
C-bus logic detects the address of the IC. This disables
D6H
5CH
B0H
E0H
08H
50H
RESOLUTION
(Hz/count)
50000
5000
6250
625
250
25
TEA6823T; TEA6825T
4300
10065
9906.25
10620.63
418.25
446.83
Preliminary specification
MIN.
RANGE (kHz)
17050
11335
11493.75
10779.38
481.75
453.18
MAX.