General Description
The MAX9485 programmable multiple-output clock
generator provides a cost-efficient solution for MPEG-2
audio systems such as DVD players, DVD drives for
multimedia PCs, digital HDTV systems, home entertain-
ment centers, and set-top boxes.
The MAX9485 accepts an input reference frequency of
27MHz from a crystal or system reference clock. The
device provides two buffered clock outputs of 256, 384,
or 768 times the chosen sampling frequency (fS) select-
ed through an I2C interface or hardwired inputs.
Sampling frequencies of 12kHz, 32kHz, 44.1kHz,
48kHz, 64kHz, 88.2kHz, or 96kHz are available. The
MAX9485 also offers a buffered 27MHz output and an
integrated voltage-controlled oscillator (VCXO) that is
tuned by a DC voltage generated from the MPEG
processor. The use of VCXO allows the audio system
clock to lock with the overall system clock.
The MAX9485 features the lowest jitter in its class, guar-
anteeing excellent dynamic performance with audio
ADCs and DACs in an MPEG-2 audio system. The
device operates with a 3.3V supply and is specified over
the -40°C to +85°C extended temperature range. The
MAX9485 is offered in 6.5mm x 4.4mm 20-pin TSSOP
and 4mm x 4mm 20-pin thin QFN packages.
Applications
Digital TVs DVD Players
Set-Top Boxes HDTVs
Home Entertainment
Centers
Features
♦27MHz Crystal with ±30ppm Frequency Reference
♦Two Buffered Output Ports with Multiple Audio
Clocks: 256, 384, or 768 Times fS
♦Supports Standard and Double Sampling Rates
(12kHz, 32kHz, 44.1kHz, 48kHz, 64kHz, 88.2 kHz,
and 96kHz)
♦I2C Interface or Hardwired Output Clock Selection
♦Separate Output Clock Enable
♦Low Jitter Typical 21ps (RMS at 73.728MHz)
♦No External Components for PLL
♦Integrated VCXO with ±200ppm Tuning Range
♦Small Footprint, Thin QFN Package, 4mm x 4mm
MAX9485
Programmable Audio Clock Generator
________________________________________________________________ Maxim Integrated Products 1