Datasheet

TVP5146M2
74
XTAL1
14.31818-MHz
Crystal
75
XTAL2
TVP5146M2
74
XTAL1
75
XTAL2
C
L1
C
L2
14.31818-MHz
1.8-V Clock
NC
R
RTC
45 CLK18 CLK
L
S
B
0
3 CLK128 CLK
23-Bit Fsc PLL Increment
Start
Bit
1 CLK
RS
Invalid
Sample
Valid
Sample
M
S
B
22
Reserved
TVP5146M2
SLES141H –JULY 2005– REVISED FEBRUARY 2012 www.ti.com
NOTE: The resistor (R) in parallel with the crystal is recommended to support a wide range of crystal types. A 100-kΩ resistor
may be used for most crystal types.
Figure 2-12. Reference Clock Configurations
2.4 Real-Time Control (RTC)
Although the TVP5146M2 decoder is a line-locked system, the color-burst information is used to
determine accurately the color subcarrier frequency and phase. This ensures proper operation with
nonstandard video signals that do not follow exactly the required frequency multiple between color
subcarrier frequency and video line frequency. The frequency control word of the internal color subcarrier
PLL and the subcarrier reset bit are transmitted via terminal 37 (GLCO) for optional use in an end system
(for example, by a video encoder). The frequency control word is a 23-bit binary number. The
instantaneous frequency of the color subcarrier can be calculated from the following equation:
F
PLL
= (F
ctrl
/ 2
23
) × F
sclk
(2)
Where,
F
PLL
is the frequency of the subcarrier PLL
F
ctrl
is the 23-bit PLL frequency control word
F
sclk
is two times the pixel frequency
Figure 2-13 shows the detailed timing diagram.
NOTE: RTC reset bit (R) is active-low, Sequence bit (S) PAL: 1 = (R-Y) line normal, 0 = (R-Y) line inverted, NTSC: 1 = no
change
Figure 2-13. RTC Timing
24 Functional Description Copyright © 2005–2012, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Link(s): TVP5146M2