LMX9830SM National Semiconductor, LMX9830SM Datasheet - Page 21

• Manufacturer Part Number: LMX9830SM
• Manufacturer: National Semiconductor

Specifications of LMX9830SM

• Lead Free Status / Rohs Status: Not Compliant

V
I
f
V
DDACT
DD
PPOSC
10.7.2 TCXO (Temperature Compensated Crystal
Oscillator)
The LMX9830 also can operate with an external TCXO (Tem-
perature Compensated Crystal Oscillator). The TCXO signal
is directly connected to the CLK+.
1.
10.7.3 Optional 32 kHz Oscillator
A second oscillator is provided (see Figure 8) that is tuned to
provide optimum performance and low-power consumption
while operating with a 32.768 kHz crystal. An external crystal
clock network is required between the X2_CKI clock input and
the X2_CKO clock output signals.The oscillator is built in a
Pierce configuration and uses two external capacitors. Table
20 provides the oscillator’s specifications.
Symbol
Input Impedance
The LMX9830 CLK+ pin has in input impedance of 2pF
capacitance in parallel with >400kW resistance
Supply Voltage
Supply Current (Active)
Nominal Output Frequency
Oscillating Amplitude
Duty Cycle
FIGURE 7. Frequency Offset with 10 pF//10 pF Capacitors
Parameter
TABLE 20. 32.768 kHz Oscillator Specifications
21
Condition
In case the 32kHz is not used, it is recommended to leave
X2_CKO open and connect X2_CKI to GND.
FIGURE 8. 32.768 kHz Oscillator
1.62
Min
40
32.768
Typ
1.8
1.8
2
Max
1.98
60
20180015
20180016
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Unit
kHz
µA
%
V
V