LC78681E Datasheet, PDF (20/23 Pages) Sanyo Semicon Device – Digital Signal Processor for Compact Disc Players

LC78681E
A clock to serve as a time base can be obtained by connecting a 16.9344 MHz crystal to X_IN and X_OUT. The OSC OFF
command stops oscillation of the crystal and the VCO. The double-speed mode can also be enabled through the use of
commands. The relationship between the crystal and VCO is shown below.
VCO playback speed
After reset
AI pin external input (8M VCO)
AI pin external input (17M VCO)
AI pin external input (LA9210)
PCK monitor output
Mode 8M
Normal speed mode
Double speed mode
—
8.6436 MHz
8.6436 MHz
4.3218 MHz
17.2872 MHz
8.6436 MHz
Mode 16M
Normal speed mode
Double speed mode
—
—
17.2872 MHz
17.2872 MHz
4.3218 MHz
8.6436 MHz
Recommended crystal oscillator constants
Manufacturer
CITIZEN WATCH CO., LTD.
Oscillator
CSA-309 (16.9344 MHz)
Cin/Cout
6 pF to 10 pF (Cin = Cout)
4.2M and 16M Pins (pin 59: 4.2M and pin 58: 16M)
Buffered 16.9344 MHz output from an externally connected 16.9344 MHz crystal is output from 16 M. It is also divided
by four to generate a 4.2336 MHz clock that is output on 4.2 M. When the OSC OFF command has been issued, these
outputs are held either high or low. The same frequency is generated in both normal and double-speed modes.
Reset Circuit (pin 55: RES)
This pin should momentarily be held low after power-on. This is set to –∞ dB for muting or to STOP for the disc motor.
Constant linear velocity servo
START
STOP
BRAKE
CLV
Muting control
0 dB
–12 db
∞
Q subcode address conditions
Address 1
Address free
Laser control
ON (low)
OFF
(high)
CONT
High
Low
OSC
ON
OFF
Track jump mode
Standard
New
Track count mode
Standard
New
No. 4521-20/23