SMSC DS – TMC2005

Page 23

Rev. 10/24/2000

Method To Connect A Crystal Clock

Connect with external parts as follows:

FIGURE 11 - CONNECTING THE CRYSTAL CLOCK

Note 1: When designing a printed circuit board, keep the patterns as short as possible and don’t cross with other

patterns.

Note 2: When using an external clock like an oscillator module, connect it to XTLI pin and leave XTLO pin open.

When designing a printed circuit board, wire between XTLI pin and oscillator should be short as possible.

nPLLTST pin

nPLLTST must be connect toVDD. The rest of input pins have pull-up resistors built in, but nPLLTST pin does not

have the pull-up resistor. Clock signal cannot ditributed into the TMC2005 if nPLLTST pin is connected GND or is

left open.

TMC2005

19

20

XTLI

XTLO

Rfb

5.1K ohm

XTAL

20MHz

Cin

22pF

Cout

22pF