LMH2190 Datasheet, PDF (1/32 Pages) National Semiconductor (TI) – Quad Channel 27 MHz Clock Tree Driver with I2C Interface

LMH2190
www.ti.com
SNAS473H – JUNE 2009 – REVISED MAY 2013
LMH2190 Quad Channel 27 MHz Clock Tree Driver with I²C Interface
Check for Samples: LMH2190
FEATURES
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•2 1 Input Clock, 4 Output Clocks
• Supports both Square or Sine Wave Input
• 1.8V Square Wave Clock Outputs
• Skewed Clock Outputs
• Independent Clock Request
• High Isolation of Supply Noise to Clock Input
• High Output to Output Isolation
• Output Drive up to 50 pF
• EMI Controlled Output Edges and EMI Filtering
• Integrated 1.8V Low-Dropout Regulator
– Low Output Noise Voltage
– 10 mA load Current
• I²C Configurable up to 400 kHz (Fast Mode)
• Ultra Low Standby Current
• V_BAT Range = 2.5V to 5.5V
APPLICATIONS
• Mobile Handsets
• PDAs
• Portable Equipment
DESCRIPTION
The LMH2190 is a quad channel configurable clock
tree driver which supplies a digital system clock to
peripherals in mobile handsets or other applications.
It provides a solution to clocking issues such as
limited drive capability for fanout or longer traces,
protection of the master clock from varying loads and
frequency pulling effects, isolation buffering from
noisy modules, and crosstalk isolation. It has very low
phase noise which enables it to drive sensitive
modules such as Wireless LAN and Bluetooth.
The LMH2190 can be clocked up to 27 MHz, and has
an independent clock request pin for each clock
output which allows the peripheral to control the
clock. It features an integrated LDO which provides
an ultra low noise voltage supply with 10 mA external
load current which can be used to supply the TCXO
or other clock source.
The I²C serial interface can be used to override the
default configuration of the device to optimize the
LMH2190 for the application. Some of these
programmable features include setting the polarity of
both the clock and the clock request inputs. In
addition, the clock outputs have programmable output
drive current to optimize for the connected load. EMI
switching noise can be controlled by configuring
output drive and skew settings.
The LMH2190 quad clock distributor is offered in a
tiny 1.61mm x 1.61mm 16 bump DSBGA package. Its
small size and low supply current make it ideal for
portable applications.
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
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