DATASHEET
SET-TOP CLOCK SOURCE MK2761A
IDT™
SET-TOP CLOCK SOURCE 1
MK2761A REV E 122109
Description
The MK2761A is a low-cost, low-jitter, high-performance
clock synthesizer for set-top box applications. Using analog
Phase-Locked Loop (PLL) techniques, the device accepts a
27 MHz crystal or clock input to produce multiple output
clocks including the processor clock, the UART clock, a
selectable audio clock, and four low skew copies of the 27
MHz. The audio clocks are frequency-locked to the 27 MHz
using our patented zero ppm error techniques. This allows
audio and video to track exactly, thereby eliminating the
need for large buffer memory.
IDT manufactures a large variety of Set-top Box and
multimedia clock synthesizers for all applications. Consult
IDT to eliminate crystals and oscillators from your board.
Features
• Packaged in a 16-pin narrow (150 mil) SOIC
• Available in Pb (lead) free package
• Selectable audio sampling frequencies support 32, 44.1,
and 48 kHz in most DACs
• 27 MHz crystal or clock input
• Processor frequency of 16.67 MHz
• Fixed clocks of 27 and 3.6864 MHz
• Zero ppm in audio clocks exactly track video frequency
• 25 mA output drive capability at TTL levels
• Advanced, low-power, sub-micron CMOS process
• Operating voltage of 5.0 V ±10%
NOTE: EOL for non-green parts to occur on 5/13/10
per PDN U-09-01
Block Diagram
27.000 MHz
Crystal
Ocsillator
ACS1:0
3.6864 MHz
VDD
GND
Clock
Synthesis and
Control
Circuitry
2
3
16.667 MHz
Audio Clock
X1
X2
27.000 MHz
crystal or clock
2
4