CY24239 Cypress Semiconductor, CY24239 Datasheet - Page 10

• Manufacturer Part Number: CY24239
• Description: Spread Spectrum Frequency Timing Generator
• Manufacturer: Cypress Semiconductor

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DC Electrical Characteristics:
AC Electrical Characteristics
T
AC clock parameters are tested and guaranteed over stated operating conditions using the stated lump capacitive load at the
clock output; Spread Spectrum is disabled.
CPU Clock Outputs, CPU_F, 1:2 (Lump Capacitance Test Load = 20 pF)
Notes:
Document #: 38-07038 Rev. **
5.
6.
7.
t
t
t
t
t
t
t
t
f
Z
Crystal Oscillator
V
C
C
Pin Capacitance/Inductance
C
C
L
Parameter
A
P
H
L
R
F
D
JC
SK
ST
Parameter
IN
o
TH
LOAD
IN,X1
IN
OUT
= 0°C to +70°C, V
X1 input threshold voltage (typical) is V
The CY24239 contains an internal crystal load capacitor between pin X1 and ground and another between pin X2 and ground. Total load placed on crystal is
20 pF; this includes typical stray capacitance of short PCB traces to crystal.
X1 input capacitance is applicable when driving X1 with an external clock source (X2 is left unconnected).
Period
High Time
Low Time
Output Rise
Edge Rate
Output Fall Edge
Rate
Duty Cycle
Jitter,
Cycle-to-Cycle
Output Skew
Frequency
Stabilization
from Power-up
(cold start)
AC Output
Impedance
X1 Input Threshold Voltage
Load Capacitance, Imposed on
External Crystal
X1 Input Capacitance
Input Pin Capacitance
Output Pin Capacitance
Input Pin Inductance
Description
DDQ3
= 3.3V±5%, f
[6]
Description
Duration of clock cycle above 2.0V
Duration of clock cycle below 0.4V
Measured from 0.4V to 2.0V
Measured from 2.0V to 0.4V
Measured on rising and falling edge at
1.25V
Measured on rising edge at 1.25V. Maxi-
mum difference of cycle time between two
adjacent cycles.
Measured on rising edge at 1.25V
Assumes full supply voltage reached with-
in 1 ms from power-up. Short cycles exist
prior to frequency stabilization.
Average value during switching transition.
Used for determining series termination
value.
Measured on rising edge at 1.25
DDQ3
[7]
/2.
T
XTL
A
= 0°C to +70°C, V
[5]
= 14.31818 MHz
Test Condition/
Comments
DDQ3
Except X1 and X2
V
Pin X2 unconnected
DDQ3
= 3.3V±5% (continued)
Test Condition
= 3.3V
Min.
3.0
2.8
10
45
1
1
CPU = 100 MHz
Min.
Typ.
20
Typ.
1.65
14
28
Max.
10.5
250
350
55
4
4
3
Max.
CY24239
Page 10 of 15
5
6
7
V/ns
V/ns
Unit
ms
ns
ns
ns
ps
ps
%
Unit
nH
pF
pF
pF
pF
V