Datasheet

OSCin
OSCin*
LMX2541
OSCin
OSCin*
0.1 PF
0.1 PF
100:
LMX2541
OSCin
OSCin*
50:
0.1 PF
0.1 PF
50:
LMX2541
LMX2541SQ2060E, LMX2541SQ2380E
LMX2541SQ2690E, LMX2541SQ3030E
LMX2541SQ3320E, LMX2541SQ3740E
www.ti.com SNOSB31I –JULY 2009–REVISED FEBRUARY 2013
Figure 32. Single-Ended Operation
For differential operation, as is the case when using an LVDS or LVPECL driver, a 100 Ω resistor is placed
across the OSCin/OSCin* traces
Figure 33. Differential Operation
A third way to configure the device is in crystal mode (XO = 1). For this, the crystal is placed across the
OSCin/OSCin* pins. Crystals are specified for a specific load capacitance, C
Load
. The load capacitors shown in
the figure each have a value of C
Load
/2.
Figure 34. Crystal Mode Operation
Current Consumption
The current consumption of the LMX2541 has many factors that influence it. Determining the current
consumption for the entire device involves knowing which blocks are powered up and adding their currents
together. The current in the electrical specifications gives some typical cases, but there could be some variation
over factors such as the phase detector frequency. Also, the output buffer current can be impacted by the
software controllable settings. By subtracting or adding combinations of the currents for the RFout buffer and
VCO divider, the current consumption for the device can be estimated for any usable configuration. The currents
for the buffer and VCO divider are as follows:
Block Current (mA)
~ 40
RF Output Buffer
(See Programmable Output Power with On/Off)
VCO Divider 32
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Product Folder Links: LMX2541SQ2060E LMX2541SQ2380E LMX2541SQ2690E LMX2541SQ3030E
LMX2541SQ3320E LMX2541SQ3740E