CY25000 Cypress Semiconductor, CY25000 Datasheet - Page 5

• Manufacturer Part Number: CY25000
• Description: Programmable Spread Spectrum Clock Generator
• Manufacturer: Cypress Semiconductor

Document #: 38-07424 Rev. *B
Reference Output (REFOUT, pin 6)
The reference clock output has the same frequency and the
same phase as the input clock. This output can be
programmed to be enabled (clock on) or disabled (High-Z,
clock off). If this output is not needed, it is recommended that
users request the disabled (High-Z, Clock Off) option.
Application Circuit
Switching Waveforms
Notes:
Duty Cycle Timing (DC = t
3. Since the load capacitors (C
4. If an external clock is used, apply the clock to XIN (pin 1) and leave XOUT (pin 8) floating (unconnected).
5. If SSON (pin 7) is LOW (V
Power-down Timing and Power-up Timing
Output Rise/Fall Time (SSCLK and REFCLK)
(Asynchronous
capacitor (C
POWER-
OUTPUT
DOWN
OUTPUT
CLKOUT
L
). Only a single 0.1-µF bypass capacitor is required on the V
)
V
0V
DD
Tr
Output Fall time (Tf) = (0.6 x V
Refer to AC Electrical Characteristics table for SR (Slew Rate) values.
Output Rise time (Tr) = (0.6 x V
SS
[3, 4, 5]
XIN
), the frequency modulation will be stopped on SSCLK pin (pin 5).
and C
1A
/t
1B
t
XOUT
1A
0.1µF
)
Power
) are provided by the CY25000, no external capacitors are needed on the XIN and XOUT pins to match the crystal load
t
1B
t
STP
V
IL
DD
VDD
DD
Tf
)/SR2 (or SR4)
High Impedance
)/SR1 (or SR3)
PD#/OE
VDD
VSS
XIN
V
DD
IH
2
1
4
3
pin.
Crystal
Frequency Modulation
The frequency modulation is programmed at 30 kHz for all
SSCLK frequencies from 3 to 200 MHz. Contact the factory if
a higher modulation frequency is required.
Power-down or Output Enable (PD# or OE, pin 3):
Users can select either PD# or OE function which are also
factory programmable.
V
0V
8
6
5
7
DD
XOUT
SSON
REFCLK
SSCLK
VDD
t
PU
CY25000
Page 5 of 10