LMH2190屬于開發(fā)板套件編程器的評估演示板及套件。由美國德州儀器公司制造生產(chǎn)的LMH2190評估和演示板及套件該系列產(chǎn)品提供了一種方便的方法，在經(jīng)過驗證的實施環(huán)境中評估某些重點器件的性能或特性。評估方法通常有完善的文檔說明，并且視乎具體情況由評估軟件提供支持。產(chǎn)品通常由印刷電路板組成，板上已裝有重點器件以及必要或有用的支持元器件，另外也可能包括其他組件，例如電纜或電源。對于數(shù)量特別多或類別獨特的器件類別(如 ADC、DAC 和開關(guān)模式電源)，評估平臺可組合為一個單獨的產(chǎn)品系列。

1FEATURES

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.