MK1418/MK1420

OPL3, OPL4 + Codec Clock Source

MDS 1418/20 A

1

Revision 013098

Printed 11/15/00

MicroClock Division of ICS•1271 Parkmoor Ave.•San Jose•CA•95126•(408)295-9800tel•(408)295-9818fax

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.

Block Diagram

Description

Features

VDD GND

Clock Synthesis

Circuitry

16.934 MHz

Output

Buffer

Output

Buffer

24.576 MHz

• 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.

Output

Buffer

33.868 MHz

(MK1420 only)

Output

Buffer

14.318 MHz

(MK1420 only)

Crystal

Oscillator

14.318 MHz

crystal or clock

X1

X2