Datasheet

10 SNAU045A LMK040xx Evaluation Board User’s Guide November 2013
Copyright © 2013, Texas Instruments Incorporated
www.ti.com
Figure 1. Bits/Pins tab.
The Bits/Pins tab allows the user to:
 setup various clock output options. This will also be reflected on the Clock Outputs tab.
 Manipulate GOE and SYNC signal states (through the 10-pin header)
 Select internal loop filter components for PLL2
 Select Reference clock functional mode: CLKin_SEL (Manual or Auto-revertive)
 Select the Loss-of-Signal (LOS) output type (LOS_TYPE).
 Select the reference clock input buffer type: CLKin0_BUFTYPE and CLKin1_BUFTYPE (MOS or Bipolar
junction)
 Enable/disable crystal mode: EN_PLL2_XTAL.
 Enable/disable PLL2 reference clock (OSCin) frequency doubler mode: EN_PLL2_REF2X.
 Set the OSCin (VCXO or XTAL) frequency (OSCin_FREQ). NOTE: This value should match the
Reference Oscillator values entered in the PLL1 and PLL2 tabs. It is important to enter the correct
frequency value in this field, as it is used by the internal state machine of the LMK040XX to execute
its calibration and tuning routine for the internal VCO. An incorrect value may result in an unlocked
condition for the synthesizer.