MK1418/MK1420
OPL3, OPL4 + Codec Clock Source
Description
The MK1418 and MK1420 are the ideal way to
generate clocks for new sound cards. The MK1420
provides clocks for Analog Devices’ AD1848,
Crystal Semiconductor’s CS4231, and Yamaha’s
OPL3L, OPL3LS, and OPL4. The MK1420 uses
either a 14.318 MHz crystal, or a 14.318 MHz bus
clock input to synthesize the clocks required to
drive the codec, and the 33.868 MHz required for
the FM or wavetable music synthesizer. The chips
are ideal for add-in sound cards and motherboards
with integrated sound. In an 8 pin SOIC, the
MK1420 can save component count, board space,
and cost over surface mount crystals, and increase
reliability by eliminating three or four mechanical
devices from the board.
MicroClock offers many other parts with stereo
codec support. The MK1430 has 5 output clocks,
the MK1448 has 7, the MK1444 has eight
including DSP clocks, and the MK1450/1 offers
Pentium™ and SCSI support, plus the stereo
codec clocks.
Features
• Packaged in 8 pin SOIC
• Input crystal or clock frequency of 14.318 MHz
• MK1418 is clock input only
• MK1420 output clock frequencies of 16.934MHz,
24.576 MHz, 33.868 MHz, and 14.318 MHz
• Advanced, low power CMOS process
• Lowest jitter in industry for best audio
performance
• Insensitive to input clock duty cycle
• 50% (typ) 14.318 MHz duty cycle with crystal
AC Coupling/Portable Applications
For applications in portable computers, it is possible
to drive the input clock with a 3.3V, 14.318MHz
clock by a.c. coupling using a 0.01µF capacitor
connected in series to the CLKIN pin. But the
operating VDD on pin 2 must be 5V±10%. This
technique is also effective if the input clock doesn’t
meet the VIH and VIL specifications on page 3.
Additional Clocks or Features
If more than these four output clocks or features
such as power down are needed, MicroClock has
many other products in development. Consult
MicroClock for your specific needs.
Block Diagram
VDD GND
Output
Buffer
14.318 MHz
crystal or clock
X1
Crystal
Oscillator
X2
16.934 MHz
24.576 MHz
33.868 MHz
(MK1420 only)
14.318 MHz
(MK1420 only)
Clock Synthesis
Circuitry
Output
Buffer
Output
Buffer
Output
Buffer
1
Revision 013098
Printed 11/15/00
MicroClock Division of ICS•1271 Parkmoor Ave.•San Jose•CA•95126•(408)295-9800tel•(408)295-9818fax
MDS 1418/20 A
ICS [ INTEGRATED CIRCUIT SYSTEMS ]
