KDK NEWS

Technical Report for Spread Spectrum Type Oscillators

EMI noise become a one of critical concern of high speed equipments.
High speed equipments requires high speed system clock, but it also cause the EMI noise.
The spread spectrum type oscillators newly developed for one of option to reduce EMI noise.

It is Surface Mount Type(7.5x5.0mm) package, and any frequency 8MHZ to 170MHZ is possible to produce by customer request.

Spread Spectrum Type:

	Model:	Size:	Frequency:	Spread Type:
	CET- TYPE	7.5x5.0mm	8.0~170Mhz	Center Spread Down Spread


Model Name:
(1)	(2)	(3)	(4)	(5)	(6)
CET	3	0	A	C	025

(1)	Model Name (CET)
(2)	Voltage Option (Only 3=3.3V)
(3)	Frequency Stability at Spread Off (0=+-100ppm, 5=+-50ppm)
(4)	Temperature Range (A=-10~70C, F=-40~85C)
(5)	Spread Type (C=Center Spread, D=Down Spread)
(6)	Modulation Ratio (3digit: 0.25%=025, 1.00%=100)

Center Spread:

	+-0.25%	+-0.5%	+-0.75%	+-1.0%	+-1.50%	+-2.0%
Model	CET30AC025	CET30AC050	CET30AC075	CET30AC100	CET30AC150	CET30AC200

Down Spread:

	-0.50%	-1.00%	-1.50%	-2.00%	-3.00%	-4.00%
Model	CET30AD050	CET30AD100	CET30AD150	CET30AD200	CET30AD300	CET30AD400

Center Spread:
Reduce EMI symmetrically from output frequency

Down Spread:
Reduce EMI down-side from output frequency

Center Spread

Down Spread

Specification:

Parameters	Conditions	CET30AC	CET30AD
Input Current (max.)	Frequency Ranges	8.0~170MHz 50mA (Load=15pF)
Modulation Rate	Center/Down Spread	+-0.25%, +-0.5%, +-0.75% +-1.0%, +-1.5%, +-2.0%	-0.5%, -1.0%, -1.5% -2.0%, -3.0%, -4.0%
Symmetry (max.)	At 0.5Vdd	45%/55%
Output Voltage Voh Vol	"0" Level (max.) "1" Level (min.)	0.33V (lol: 8mA) 2.97V(lol:8mA)
Rise/Fall Time	At 0.2Vdd~0.8Vdd	3.0ns
Jitter	Cycle to Cycle	400ps max(<133MHZ) (SS ON) 250ps max >=133MHZ) (SS ON)
Modulation Frequency		30kHz~33kHz
Start-Up Time (max.)	Frequency Range	10ms
E/D Function	#1 Open #1 >=0.7Vdd #1 <=0.3Vdd	#4 Active #4 Active #4 High Z

Center Spread Spectrum:

Spread Off

Spread +-2.0%

Clock Form at Spread +-2.0%

Down Spread Spectrum:

Spread Off

Spread -4.0%

Clock Form at Spread -4.0%

Applications
Laser Printer, Scanner, Fax, Modem, Wireless LAN terminal, Printer Server, ADSL terminal, Storage Systems(CD-ROM, VCD, DVD and HDD)

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SPEC SHEET (CET-Type)