CY25701 Cypress Semiconductor Corporation., CY25701 Datasheet - Page 2

• Manufacturer Part Number: CY25701
• Description: Programmable High Frequency Crystal Oscillator With Spread Spectrum Ssxo And No Spread Spectrum Xo Option
• Manufacturer: Cypress Semiconductor Corporation.

Pin Definition
Functional Description
The CY25701 is a Spread Spectrum Crystal Oscillator (SSXO)
IC used to reduce the EMI found in today’s high speed digital
electronic systems.
The device uses a Cypress proprietary PLL and Spread
Spectrum Clock (SSC) technology to synthesize and modulate
the frequency of the embedded input crystal. By frequency
modulating the clock, the measured EMI at the fundamental and
harmonic frequencies are greatly reduced. This reduction in
radiated energy can significantly reduce the cost of complying
with regulatory agency (EMC) requirements and improve
time-to-market without degrading system performance.
The CY25701 uses a programmable configuration memory array
to synthesize output frequency and spread%.
The spread percentage is programmed to either center spread
or down spread with various spread percentages. The range for
center spread is from ±0.25% to ±2.00%. The range for down
spread is from –0.5% to –4.0%. Contact the factory for smaller
or larger spread percentage amounts if required. Refer to
for spread selection and no spread values.
The frequency modulated SSCLK output is programmable from
10 to 166 MHz.
The CY25701 is available in a 4-pin ceramic SMD package with
an operating temperature range of –40 to 85°C.
Table 1. Programming Data Requirement
Document Number: 001-07313 Rev. *B
Note
1
2
3
4
1. ±0.0% or Code “Z” for XO (No-Spread) option.
Program Value
Pin Function
Pin
Pin Name
Units
Pin#
OE
VSS
SSCLK
VDD
Name
Output Frequency
ENTER DATA
SSCLK
MHz
3
Output Enable pin: Active HIGH. If OE = 1, SSCLK is enabled
Power supply ground
Spread spectrum clock output (with or without spread)
3.3V power supply
Table 2
Spread Percent Code
ENTER DATA
Programming Description
Factory and Field Programmable CY25701
Factory and field programming is available for samples and
manufacturing by Cypress and its distributors. Submit your
request to the local Cypress Field Application Engineer (FAE) or
sales representative. Once the request is processed, you will
receive a new part number, samples, and data sheet with the
programmed values. This part number is used for additional
sample request and the production orders. Contact your local
Cypress FAE or sales representative for details.
Additional information on the CY25701 is available at the
Cypress web site www.cypress.com.
Output Frequency, SSCLK Output (SSCLK, pin 3)
The modulated frequency at the SSCLK output is produced by
synthesizing from the embedded crystal oscillator frequency
input. The range of synthesized clock is from 10 to 166 MHz.
Spread Percentage (SSCLK, pin 3)
The SSCLK spread is programmable to various spread
percentage values from ±0.25% to ±2.0% for center spread and
from –0.5% to –4.0% for down spread. Refer to
available spread options. Enter ±0.0% (No spread) for XO
(crystal oscillator) without spread option.
Frequency Modulation (SSCLK, pin 3)
The default frequency modulation is programmed at 31.5 kHz for
all SSCLK frequencies from 10 to 166 MHz. Alternate frequency
modulations at 30.1 kHz or 32.9 kHz are selectable using Cyber-
ClocksOnline™ software. Contact the factory for other alternate
modulation frequencies if required.
SSCLK
%
3
Description
[1]
Frequency Modulation
ENTER DATA 31.5
SSCLK
kHz
3
CY25701
Page 2 of 8
Table 2
for
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