Recomendable Oscillation Circuit

Crystal Clock Oscillator
n Measured Load Conditions
Measuring point VDD
Measuring point
RL
OSC OUT
1TTL = 5LSTTL
OSC OUT
CL
CL
Figure 1
Load corresponding to TTL output
Figure 2
Load corresponding to C-MOS output
TTL
1
CL
15 pF
2
15 pF
2 kΩ
5
15 pF
800 Ω
10
15 pF
400 Ω
RL
4 kΩ
Note: CL includes the capacitance
of the measurement system.
n Circuit Diagrams
Examples of a crystal oscillator circuit diagram
(i) 2725T/2725Q/2725Z/NZ2520SB/NZ2520SD/NF2520SF/NZ2016SA
(iii) 2765E
VDD
ST
DIVIDER
1/2N
(N = 0 to 3)
PLL + SS
(SS: Spread spectrum)
OUT
OUT
ST
(RUP is incorporated.)
(ii) 2775Y/2775W/2785V/2795Y/2795W/2795V
PLL
OUT
ST
(RUP is incorporated.)
P-ROM
cc07_090920_circuit_e