C8051F330-TB Silicon Laboratories Inc, C8051F330-TB Datasheet - Page 115

• Manufacturer Part Number: C8051F330-TB
• Description: BOARD PROTOTYPING W/C8051F330
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F330-TB

• Contents: Board
• Processor To Be Evaluated: C8051F33x
• Interface Type: RS-232, UART
• Operating Supply Voltage: 7 V to 15 V
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: C8051F330
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

The capacitors shown in the external crystal configuration provide the load capacitance required by the
crystal for correct oscillation. These capacitors are "in series" as seen by the crystal and "in parallel" with
the stray capacitance of the XTAL1 and XTAL2 pins.
Note: The desired load capacitance depends upon the crystal and the manufacturer. Please refer to the
crystal data sheet when completing these calculations.
For example, a tuning-fork crystal of 32.768 kHz with a recommended load capacitance of 12.5 pF should
use the configuration shown in Figure 13.1, Option 1. The total value of the capacitors and the stray capac-
itance of the XTAL pins should equal 25 pF. With a stray capacitance of 3 pF per pin, the 22 pF capacitors
yield an equivalent capacitance of 12.5 pF across the crystal, as shown in Figure 13.2.
Figure 13.2. External 32.768 kHz Quartz Crystal Oscillator Connection Diagram
22pF*
* Capacitor values depend on
crystal specifications
32.768 kHz
10M
Rev. 1.7
22pF*
XTAL1
XTAL2
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