MK3771-17 Datasheet, PDF (1/8 Pages) Integrated Circuit Systems – VCXO and HDTV Set-Top Clock Source

MK3771-17
VCXO and HDTV Set-Top Clock Source
Description
The MK3771-17 is a low cost, low jitter,
high-perfomance VCXO and clock synthesizer
designed for set-top boxes and HDTV receivers. The
on-chip Voltage Controlled Crystal Oscillator accepts a
0 to 3.3 V input voltage to cause the output clocks to
vary by ±100 ppm. Using ICS’s patented VCXO and
analog Phase-Locked Loop (PLL) techniques, the
device uses an inexpensive 13.5 MHz crystal input to
produce multiple output clocks including selectable
BCLK, a selectable audio clock, two communications
clocks, a 13.5 MHz clock, and three 27 MHz clocks. All
clocks are frequency locked to the 27 MHz output (and
to each other) with zero ppm error, so any output can
be used as the VCXO output.
Block Diagram
AS2:0
3
BS1, BS0
2
CS
VIN
XI
13.5 MHz
pullable crystal
XO
VS
Voltage
Controlled
X8
Crystal
PLL
Oscillator
Features
• Packaged in 28-pin SSOP
• Available in Pb (lead) free package
• HDTV frequencies of 74.25 and 74.175824 MHz
• On-chip patented VCXO with pull range of 200 ppm
(minimum)
• VCXO tuning voltage of 0 to 3.3 V
• Supports Ethernet with 20 and 25 MHz clocks
• Modem clocks of 11.0592 and 24.576 MHz option
• Audio clocks support 32 kHz, 44.1 kHz, 48 kHz and
96 kHz sampling rates
• Zero ppm synthesis error in all clocks (all exactly
track 27MHz VCXO)
• Uses an inexpensive 13.5 MHz crystal
• Full CMOS output swings with 12 mA output
• drive capability at TTL levels
• Advanced, low power, sub-micron CMOS process
• 3.3 V ±5% operating supply
PLL Clock
Synthesis
Circuitry
Divide
Logic
Audio Clock
BCLK
CCLK1
CCLK2
108 MHz or 27 MHz
54 MHz or 27 MHz
27 MHz
13.5 MHz or 27 MHz
MDS 3771-17 C
1
Revision 083104
Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel [phone] ● www.icst.com