NXP Semiconductors
14. Application information
HEF4521B
24-stage frequency divider and oscillator
Ro
1.8 MΩ
VDD
R(1)
VDD
VDD1
A1
Y1
Y2
Q18
A2
HEF4521B
CS
CT
MR
VSS
Q24
VSS1
(1) Optional for low power operation.
Fig 7. Crystal oscillator circuit
R(1)
001aae713
Table 11. Typical characteristics for crystal oscillator
See Figure 7.
Parameter
Crystal characteristics
Resonance frequency
Crystal cut
Equivalent resistance; RS
External resistor/capacitor values
Ro
CT
CS
500 kHz circuit 50 kHz circuit Unit
500
50
kHz
S
N
-
1
6.2
kΩ
47
750
kΩ
82
82
pF
20
20
pF
HEF4521B_5
Product data sheet
Rev. 05 — 5 November 2009
© NXP B.V. 2009. All rights reserved.
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