CF5008A1-2 View Datasheet(PDF) - Nippon Precision Circuits
Part Name
Description
MFG CO.
'CF5008A1-2' PDF : 10 Pages View PDF
CF5008A1
FUNCTIONAL DESCRIPTION
Standby Function
The oscillator output on Q changes as shown in the following table when INH goes LOW.
INH
HIGH (or open)
LOW
Q
fO
High impedance
Oscillator
Normal operation
Normal operation
TYPICAL APPLICATION CIRCUIT
Typical circuit structures (CG and CD) that use a varicap device have a reduced frequency range due to the
effects of parasitic capacitance. The CF5008A1, however, has built-in components CC and RB2 that are con-
nected in series with the varicap device, increasing the frequency output range.
XT
X'tal
Control
Input
VCXO Module
Rf
CG
CD
Rd
VARI−CAP
XT2
RB2
CC
CF5008
Control Circuits
VDD
VCC
VSS
GND
Q
Output
Rp INH
Output
Enable
PARASITIC CAPACITANCE
Parasitic capacitance are unwanted capacitance effects that occur due to the junction capacitance where the
protection diodes and transistor drains are connected to the substrate. The following equivalent circuit figure
shows the calculated parasitic capacitances. The surface area for each component is calculated from the IC lay-
out pattern, and the capacitance calculated per unit area.
Rf 150k
CG
XT
5.01p 20p
2.4p Divider
(1/1)
Rd
CD
10p
CC
70p
VDD
VSS
Q
XT2
4.7p
RB2
50k
Rp
Control 100k
Circuits
INHN
NIPPON PRECISION CIRCUITS—6
Share Link: 
