ML7404 Family LSIs
Hardware Design Manual
FEXL7404DG-03
3
2. Clock Input
2.1. Crystal Oscillator circuit
Figure 2.1 shows a configuration example of the crystal oscillator circuit. Capacitors should be connected to XIN
(#5) and XOUT (#6) pins to stabilize 36MHz crystal oscillator circuit. To determine the component values, the
oscillator circuit evaluation on your designing board is required, since the stray capacitor of the board will be
influenced.
Amplitude level, oscillation margin, frequency accuracy and oscillator circuit start-up time should be considered
and evaluated.
Figure 2.1.1 Crystal Oscillator circuit configurations
2.1.1. Circuit component values for crystal oscillator circuit
It is recommended to ask your oscillator manufacturer to evaluate the matching component values on the
assembled board. The following tables show the matching component values with LAPIS Semiconductor RF
board as reference.
Table 2.1.1 Representative matching component values
Manufacturer
Oscillator Type
Frequency
(MHz)
Equivalent
series resister
Max(
Ω)
Load
capacitor
(pF)
Component
Values
Operating Condition
(+/-10ppm)
C4
(pF)
C5
(pF)
R11
(
Ω
)
Power supply
voltage range
VDDIO(V)
Temperature range
(
℃
)
NDK
NX2016SA
(EXS00A-CS07050)
36
T.B.D.
6
T.B.D.
T.B.D.
T.B.D.
1.8 to 3.6
T.B.D.
EPSON
T.B.D.
36
T.B.D.
T.B.D.
T.B.D.
T.B.D.
T.B.D.
1.8 to 3.6
T.B.D.
YOKETAN
T.B.D.
36
T.B.D.
T.B.D.
T.B.D.
T.B.D.
T.B.D.
1.8 to 3.6
T.B.D.
[Note] These component values appropriate for use on the LAPIS Semiconductor’s RF board. It is not guaranteed to
obtain same result on your specific board.
[Note] The frequency tolerance of reference clock must be /-2.5ppm in order to correspond to IEEE802.15.4k.
TCXO should be used.
X
IN
(#5)
C4
X’tal
X
O
U
T
(#6)
C5
R0_5
