Datasheet

LMK00105

www.ti.com

SNAS579F –MARCH 2012–REVISED MAY 2013

Table 2. CLKin Input vs. Output States

CLKin CLKin* Output State

Open Open Logic Low

Logic Low Logic Low Logic Low

Logic High Logic Low Logic High

Logic Low Logic High Logic Low

OSCin/OSCout Pins

The LMK00105 has a crystal oscillator which will be powered up when OSCin is selected. Alternatively, OSCin

may be driven by a single ended clock, up to 200 MHz, instead of a crystal. Refer to Crystal Interface for more

information. If Crystal mode is selected and the pins do not have an AC signal applied to them, Table 3 will be

the state of the outputs. If Crystal mode is selected an open state is not allowed on OSCin, as the outputs may

oscillate due to the crystal oscillator circuitry.

Table 3. OSCin Input vs. Output States

OSCin Output State

Open Not Allowed

Logic Low Logic High

Logic High Logic Low

CLOCK OUTPUTS

The LMK00105 has 5 LVCMOS outputs.

Output Enable Pin

When the output enable pin is held High, the outputs are enabled. When it is held Low, the outputs are held in a

Low state as shown in Table 4.

Table 4. Output Enable Pin States

OE Outputs

Low Disabled (Hi-Z)

High Enabled

The OE pin is synchronized to the input clock to ensure that there are no runt pulses. When OE is changed from

Low to High, the outputs will initially have an impedance of about 400 Ω to ground until the second falling edge of

the input clock and starting with the second falling edge of the input clock, the outputs will buffer the input. If the

OE pin is taken from Low to High when there is no input clock present, the outputs will either go high or low and

stay a that state; they will not oscillate. When the OE pin is taken from High to Low the outputs will be Low after

the second falling edge of the clock input and then will go to a Disabled (Hi-Z) state starting after the next rising

edge.

Using Less than Five Outputs

Although the LMK00105 has 5 outputs, not all applications will require all of these. In this case, the unused

outputs should be left floating with a minimum copper length to minimize capacitance. In this way, this output will

consume minimal output current because it has no load.

NOTE

For best soldering practices, the minimum trace length should extend to include the pin

solder mask. This way during reflow, the solder has the same copper area as connected

pins. This allows for good, uniform fillet solder joints helping to keep the IC level during

reflow.

Product Folder Links: LMK00105