SM8761 Nippon_Precision_Circuits America, SM8761 Datasheet - Page 9

• Manufacturer Part Number: SM8761
• Description: Spread Spectrum Clock Generator
• Manufacturer: Nippon_Precision_Circuits America

Typical Connection Circuit
A typical connection circuit diagram is shown in Figure 4.
1) The SM8761 series oscillator circuit between XT and XTN has a built-in feedback resistor (approximately
2) The oscillator circuit capacitances C101 and C102 connected to XTN and XT, to match the crystal load
3) If using an external clock input on XT, then connections to XT and XTN should be as shown in figure 3.
4) R201 is impedance matching resistor for board pattern.
5) C201 and C202 are bypass capacitors inserted between the supply voltage lines.
MSEL1 and MSEL0 Connection Method
MSEL1 and MSEL0 both support a 1/2V
Typical connection circuits for each input level shown in figure 5. "H" level is input by connection to VDD, and
"L" level by connection to VSS. "M" level is input by connection to the center tap of two identical resistances
in series between VDD and VSS. The recommended resistance is 4.7kΩ.
250kΩ).
capacitor.
C201 is a 0.1µF (approximately) multi-layer ceramic capacitor connected directly alongside the SM8761
series.
C202 is a 33µF (approximately) electrolytic capacitor.
Note. This is a sample connection diagram only, and its use is not a guarantee of SM8761 series device characteristics.
MSEL1
MSEL0
(a)“H” level
VDD
VSS
TSTN
XTN
Application Load
VSS
VDD
C202
33µF
Figure 5. MSEL1 and MSEL0 typical connections
Figure 4. Typical connection circuit
C201
0.1µF
0 to 22Ω
R201
DD
VSS
"M" level for 3-value ("H", "M", "L") DC voltage input control.
MSEL1
MSEL0
TSTN
SM8761 series
XTN
(b)“M” level
C101
XT
VDD
VSS
CLKOUT
VDD
VSS
X'tal
R301
4.7kΩ
R302
4.7kΩ
MSEL1
MSEL0
SM8761
TSTN
XTN
IC1
C102
NIPPON PRECISION CIRCUITS INC.—9
VSS
MSEL1
MSEL0
(c)“L” level
MSEL1
MSEL0
TSTN
XTN
VSS