TEF6700HL NXP Semiconductors, TEF6700HL Datasheet - Page 29

• Manufacturer Part Number: TEF6700HL
• Description: Car Radio Tuner Front-end For Digital If
• Manufacturer: NXP Semiconductors

Philips Semiconductors
2003 Oct 21
handbook, full pagewidth
Car radio tuner front-end for digital IF
AFHOLD signal is used to hold the quality information for signal processing of the main channel during the alternative frequency jumps. PLL registers
are loaded during load PLL = 1, but actual frequency jumps take place at the falling edge of this signal. IF counting is carried out during AFSAMPLE = 1.
10 s after falling edge of AFSAMPLE result is valid for AF and remains valid until read by microcontroller. Quality tests in a car IF DSP IC (e.g.
SAA7724H) should take place 2 ms after falling edge of AFHOLD.
t
t
t
t
1
2
3
4
(e.g. SAA7724H)
audio output of a
is the internal TEF6700HL clock related logic delay: 100 s.
should be >1.1 ms to ensure correct loading of PLL for the main channel.
should be >0 to ensure inaudible update.
= 500 s.
car IF DSP IC
AFSAMPLE
AFHOLD
load PLL
(internal)
I
2
C-bus
AF channel
AF = 1
t 1
0
Fig.6 Inaudible AF update timing diagram.
t 2
1
main channel
2
AF = 1
quality test
29
3
t 3
4
t 4
5
6
7
t (ms)
Product specification
TEF6700HL
8
MHC520