cx24118a NXP Semiconductors, cx24118a Datasheet - Page 19

• Manufacturer Part Number: cx24118a
• Description: Advanced Modulation Digital Satellite Tuner
• Manufacturer: NXP Semiconductors

NXP Semiconductors
Figure 4.
CX24118A_N_2
Product data sheet
Third-Overtone Crystal Oscillator External Circuit
CX24118A
40 MHz sinusoidal clock is produced, and when OUTRefDiv = 1, a 20 MHz square clock is
produced (
The third overtone crystal requires external circuitry to load the crystal properly at the third-
overtone frequency while suppressing the fundamental frequency. This circuit is shown in
Figure
components should be RF type components (high Q) with good characteristics at 40 MHz.
Table 4.
The selected crystal should be a high-quality crystal with minimum drive level dependencies.
Table 5
or better.
6
4, and the recommended component values are listed in
lists the required crystal characteristics. Component tolerances should be 5 percent
35
when OUTRefDiv = 1 mode is used, the XTAL_BIAS pin needs to be grounded)
Recommended Component Values for Third-Overtone Crystal Oscillator
External Circuit
C1
Component
8
XTAL1
C
C
C
Rev. 02 — 8 September 2009
L
1
1
2
3
C2
To System
XTAL2
9
C3
: 2
L1
OUTRefDiv
1
0
Chapter 2: Functional Descriptions
To Demodulator
390 nH
Value
22 pF
56 pF
1 nF
Table
CX24118A
4. The external
© NXP B.V. 2009. All rights reserved.
102322_014
.
19