SDA9257 Datasheet, PDF (1/36 Pages) Siemens Semiconductor Group – Clock Sync Generator

Clock Sync Generator
SDA 9257
Preliminary Data
Features
q All settings made by I²C Bus
q PLL lock-in behavior can be set to TV- or VCR mode
q Automatic clamping of CVBS input
q Provides all horizontal and vertical sync signals and
clocks for operating PAMUX, analog color decoders,
the A/D converters, PSND and Featurebox
q Free-running capability
q Frequency generator function possible with digitally
adjustable frequency
P-DIP-28-1
q Lock-in function of the PLL on CVBS also possible
with externally supplied 24-MHz or 27-MHz clock
q Multi-standard operation (50 Hz, 60 Hz; PAL, NTSC, SECAM)
q Vertical noise suppression and 50/60-Hz detection
q Serial digital output for actual frequency value and CVBS-black level
Applications
q Memory based image improvement with analog color decoder
q Memory based image improvement with digital multi-standard decoder
q Free-running sync generator
q Digital frequency synthesizer
MOS IC
Type
SDA 9257
Ordering Code
Q67100-H5038
Package
P-DIP-28-1
Functional Description
The clock sync generator consists essentially of the following function blocks (refer to block
diagram):
q Analog clamping
q 7-bit, 27-MHz A/D converter
q Sync processor with digital horizontal PLL, vertical sync processor and pulse generator
q Clock generator with discrete timing oscillator, D/A converter, analog PLL and divider, as well as
a crystal oscillator
q I²C Bus interface
q Button flutter elimination
Semiconductor Group
182
01.94