Datasheet
TVP5150AM1
5
XTAL1
14.31818-MHz
Crystal
6
XTAL2
TVP5150AM1
5
XTAL1
6
XTAL2
C
L1
C
L2
14.31818-MHz
TTL Clock
R
TVP5150AM1
SLES209E–NOVEMBER 2007–REVISED OCTOBER 2011
www.ti.com
3.15.2.3 I
2
C Timing Requirements
The TVP5150AM1 decoder requires delays in the I
2
C accesses to accommodate its internal processor's
timing. In accordance with I
2
C specifications, the TVP5150AM1 decoder holds the I
2
C clock line (SCL) low
to indicate the wait period to the I
2
C master. If the I
2
C master is not designed to check for the I
2
C clock
line held-low condition, then the maximum delays must always be inserted where required. These delays
are of variable length; maximum delays are indicated in the following diagram:
Normal register writing addresses 00h to 8Fh (addresses 90h to FFh do not require delays).
Slave
Start address Ack Subaddress Ack Data (XXh) Ack Wait 64 µs Stop
(B8h)
The 64-µs delay is for all registers that do not require a reinitialization. Delays may be more for some
registers.
3.16 Clock Circuits
An internal line-locked PLL generates the system clock (SCLK). A 14.31818-MHz clock is required to drive
the PLL. This may be input to the TVP5150AM1 decoder on terminal 5 (XTAL1), or a crystal of
14.31818-MHz fundamental resonant frequency may be connected across terminals 5 and 6 (XTAL2).
Figure 3-8 shows the reference clock configurations. For the example crystal circuit shown (a
parallel-resonant crystal with 14.31818-MHz fundamental frequency), the external capacitors must have
the following relationship:
C
L1
= C
L2
= 2C
L
– C
STRAY
where C
STRAY
is the terminal capacitance with respect to ground, and C
L
is the crystal load capacitance
specified by the crystal manufacturer.
Figure 3-8 shows the reference clock configurations.
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 3-8. Reference Clock Configurations
Clock source frequency should have an accuracy of ±50 ppm (max).
22 Functional Description Copyright © 2007–2011, Texas Instruments Incorporated
Submit Documentation Feedback
www.ti.com: TVP5150AM1