NB2779A
Low Power, Reduced EMI
Clock Synthesizer
The NB2779A is a versatile spread spectrum frequency modulator
designed specifically for a wide range of clock frequencies. The
NB2779A reduces ElectroMagnetic Interference (EMI) at the clock
source, allowing system wide reduction of EMI of all clock dependent
signals. The NB2779A allows significant system cost savings by
reducing the number of circuit board layers, ferrite beads and
shielding that are traditionally required to pass EMI regulations.
The NB2779A uses the most efficient and optimized modulation
profile approved by the FCC and is implemented by using a
proprietary all digital method.
The NB2779A modulates the output of a single PLL in order to
“spread” the bandwidth of a synthesized clock, and more importantly,
decreases the peak amplitudes of its harmonics. This results in
significantly lower system EMI compared to the typical narrow band
signal produced by oscillators and most frequency generators.
Lowering EMI by increasing a signal’s bandwidth is called ‘spread
spectrum clock generation’.
The NB2779A is targeted towards all portable devices with very
low power requirements like MP3 players and digital still cameras.
Features
• Generates an EMI Optimized Clocking Signal at the Output
• Integrated Loop Filter Components
• Operates with a 3.3 V / 2.5 V Supply
• Operating Current less than 4.0 mA
• Low Power CMOS Design
• Input Frequency Range: 13 MHz to 30 MHz for Both Voltages
• Generates a 1X Low EMI Spread Spectrum clock of the Input
Frequency
• Frequency Deviation "1% @ 16 MHz
• Available in TSOP−6 Package (TSOT−23−6)
• Pb−Free Package is Available
http://onsemi.com
MARKING
DIAGRAM*
6
1
(Note: Microdot may be in either location)
*For additional marking information, refer to
Application Note AND8002/D.
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 7 of this data sheet.
TSOP−6
(TSOT−23−6)
SN SUFFIX
CASE 318G
E06 = Specific Device Code
A = Assembly Location
Y = Year
W = Work Week
G = Pb−Free Package
E06AYWG
1
G
© Semiconductor Components Industries, LLC, 2006
December, 2006 − Rev. 3
1 Publication Order Number:
NB2779A/D
NB2779A
PD
V
Modulation
XIN/CLKIN
XOUT
Crystal
Oscillator
Frequency
Divider
Feedback
Divider
Phase
Detector
Loop
Filter
V
V
Figure 1. Block Diagram
Table 1. KEY SPECIFICATIONS
Description Specification
Supply Voltages VDD = 3.3 V / 2.5 V
Frequency Range For 2.5 V Supply
For 3.3 V Supply
Cycle−to−Cycle Jitter 200 ps (maximum)
Output Duty Cycle 45/55% (worst case)
Modulation Rate Equation FIN/640
Frequency Deviation "1% (TYP) @ 16 MHz
13 MHz < CLKIN < 30 MHz
13 MHz < CLKIN < 30 MHz
CO
DD
SS
PLL
Output
Divider
ModOUT
PD
XOUT
XIN/CLKIN
1
2
NB2779A
3
6
5
4
V
SS
ModOUT
V
DD
Figure 2. Pin Configuration
Table 2. PIN DESCRIPTION
Pin # Pin Name Type Description
1 PD I Powerdown control pin. Pull low to enable powerdown mode. Connect to VDD if not used.
2 XOUT O Crystal connection. If using an external reference, this pin must be left unconnected.
3 XIN/CLKIN I Crystal connection or external reference frequency input. This pin has dual functions. It can be
4 V
DD
5 ModOUT O Spread spectrum clock output.
6 V
SS
connected either to an external crystal or an external reference clock.
P Power supply for the entire chip.
P Ground connection.
http://onsemi.com
2
NB2779A
Figure 3. Modulation Profile
Table 3. MAXIMUM RATINGS
Symbol Description Rating Unit
V
V
DD,
IN
T
STG
T
A
T
s
T
J
T
DV
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
Voltage on any pin with respect to Ground 0.5 to +7.0 V
Storage Temperature −65 to +125 °C
Operating Temperature 0 to 70 °C
Max. Soldering Temperature (10 sec) 260 °C
Junction Temperature 150 °C
Static Discharge Voltage (As per MIL−STD−883, Method 3015) 2 kV
http://onsemi.com
3
NB2779A
Table 4. DC ELECTRICAL CHARACTERISTICS FOR 2.5 V SUPPLY
(Test Conditions: All parameters are measured at room temperature 25°C)
Symbol Description Min Typ Max Unit
V
IL
V
IH
I
IL
I
IH
I
XOL
I
XOH
V
OL
V
OH
I
DD
I
CC
V
DD
t
ON
Z
OUT
NOTE: Device will meet the specifications after thermal equilibrium has been established when mounted in a test socket or printed circuit
board with maintained transverse airflow greater than 500 lfpm. Electrical parameters are guaranteed only over the declared
operating temperature range. Functional operation of the device exceeding these conditions is not implied. Device specification limit
values are applied individually under normal operating conditions and not valid simultaneously.
1. XIN/CLKIN pin and PD
and XIN/CLKIN input are stable, PD pin is made high from low.
2. V
DD
Input LOW Voltage GND − 0.3 0.8 V
Input HIGH Voltage 2.0 VDD + 0.3 V
Input LOW Current −35
Input HIGH Current 35
mA
mA
XOUT Output LOW Current (@ 0.5 V, VDD = 2.5 V) 3.0 mA
XOUT Output HIGH Current (@ 1.8 V, VDD = 2.5 V) 3.0 mA
Output LOW Voltage (VDD = 2.5 V, IOL = 8.0 mA) 0.6 V
Output HIGH Voltage (VDD = 2.5 V, IOH = 8.0 mA) 1.8 V
Static Supply Current (Note 1) 10
mA
Dynamic Supply Current (2.5 V, 16 MHz, and No Load) 3.0 mA
Operating Voltage 2.375 2.5 2.625 V
Powerup Time (first locked cycle after powerup) (Note 2) 5.0 mS
Clock Output Impedance 50
W
are pulled low.
Table 5. AC ELECTRICAL CHARACTERISTICS FOR 2.5 V SUPPLY
Symbol Description Min Typ Max Unit
CLKIN Input Frequency 13 30 MHz
ModOUT Output Frequency 13 30 MHz
f
d
tLH (Note 3) Output Rise Time (measured at 0.7 V to 1.7 V) 0.7 1.4 1.8 ns
tHL (Note 3) Output Fall Time (measured at 1.7 V to 0.7 V) 0.4 0.9 1.1 ns
t
JC
t
D
NOTE: Device will meet the specifications after thermal equilibrium has been established when mounted in a test socket or printed circuit
board with maintained transverse airflow greater than 500 lfpm. Electrical parameters are guaranteed only over the declared
operating temperature range. Functional operation of the device exceeding these conditions is not implied. Device specification limit
values are applied individually under normal operating conditions and not valid simultaneously.
3. t
and tHL are measured at capacitive load of 15 pF.
LH
Frequency Deviation Input Frequency = 13 MHz
Input Frequency = 30 MHz
±1.15
±0.6
Jitter (Cycle−to−Cycle) 200 ps
Output Duty Cycle 45 50 55 %
%
http://onsemi.com
4
NB2779A
Table 6. DC ELECTRICAL CHARACTERISTICS FOR 3.3 V SUPPLY
(Test Conditions: All parameters are measured at room temperature 25°C)
Symbol Description Min Typ Max Unit
V
IL
V
IH
I
IL
I
IH
I
XOL
I
XOH
V
OL
V
OH
I
DD
I
CC
V
DD
t
ON
Z
OUT
NOTE: Device will meet the specifications after thermal equilibrium has been established when mounted in a test socket or printed circuit
board with maintained transverse airflow greater than 500 lfpm. Electrical parameters are guaranteed only over the declared
operating temperature range. Functional operation of the device exceeding these conditions is not implied. Device specification limit
values are applied individually under normal operating conditions and not valid simultaneously.
4. XIN/CLKIN pin and PD
and XIN/CLKIN input are stable, PD pin is made high from low.
5. V
DD
Input LOW Voltage GND − 0.3 0.8 V
Input HIGH Voltage 2.0 VDD + 0.3 V
Input LOW Current −35
Input HIGH Current 35
mA
mA
XOUT Output LOW Current (@ 0.4 V, VDD = 3.3 V) 3.0 mA
XOUT Output HIGH Current (@ 2.5 V, VDD = 3.3 V) 3.0 mA
Output LOW Voltage (VDD = 3.3 V, IOL = 8.0 mA) 0.4 V
Output HIGH Voltage (VDD = 3.3 V, IOH = 8.0 mA) 2.5 V
Static Supply Current (Note 4) 10
mA
Dynamic Supply Current (3.3 V, 16 MHz, and No Load) 3.5 mA
Operating Voltage 2.7 3.3 3.6 V
Powerup Time (first locked cycle after powerup) (Note 5) 5.0 mS
Clock Output Impedance 45
W
are pulled low.
Table 7. AC ELECTRICAL CHARACTERISTICS FOR 3.3 V SUPPLY
Symbol Description Min Typ Max Unit
CLKIN Input Frequency 13 30 MHz
ModOUT Output Frequency 13 30 MHz
f
d
tLH (Note 6) Output Rise Time (measured at 0.8 V to 2.0 V) 0.5 1.1 1.3 ns
tHL (Note 6) Output Fall Time (measured at 2.0 V to 0.8 V) 0.3 0.8 0.9 ns
t
JC
t
D
NOTE: Device will meet the specifications after thermal equilibrium has been established when mounted in a test socket or printed circuit
board with maintained transverse airflow greater than 500 lfpm. Electrical parameters are guaranteed only over the declared
operating temperature range. Functional operation of the device exceeding these conditions is not implied. Device specification limit
values are applied individually under normal operating conditions and not valid simultaneously.
6. t
and tHL are measured at capacitive load of 15 pF.
LH
Frequency Deviation Input Frequency = 13 MHz
Input Frequency = 30 MHz
±1.15
±0.6
Jitter (Cycle−to−Cycle) 200 ps
Output Duty Cycle 45 50 55 %
%
http://onsemi.com
5
NB2779A
XIN XOUT
Crystal
C1 = 27 pF C2 = 27 pF
R1 = 510 W
Figure 4. Typical Crystal Oscillator Circuit
Table 8. TYPICAL CRYSTAL SPECIFICATIONS
Fundamental AT Cut Parallel Resonant Crystal
Nominal Frequency 14.31818 MHz
Frequency Tolerance ±50 ppm or better at 25°C
Operating Temperature Range −25°C to +85°C
Storage Temperature −40°C to +85°C
Load Capacitance 18 pF
Shunt Capacitance 7 pF Maximum
ESR
25 W
http://onsemi.com
6
NB2779A
ORDERING INFORMATION
Device Marking Temperature Range Package Shipping
NB2779ASNR2 E06 0°C − 70°C TSOP−6
(TSOT−23−6)
NB2779ASNR2G E06 0°C − 70°C TSOP−6
(TSOT−23−6)
(Pb−Free)
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
2500 Tape & Reel Now
2500 Tape & Reel Contact
†
Availability
Sales
Representative
http://onsemi.com
7
NB2779A
PACKAGE DIMENSIONS
TSOP−6
CASE 318G−02
ISSUE S
0.05 (0.002)
D
456
H
E
1
23
E
b
e
A
A1
c
L
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. MAXIMUM LEAD THICKNESS INCLUDES LEAD
FINISH THICKNESS. MINIMUM LEAD
THICKNESS IS THE MINIMUM THICKNESS OF
BASE MATERIAL.
4. DIMENSIONS A AND B DO NOT INCLUDE
MOLD FLASH, PROTRUSIONS, OR GATE
BURRS.
DIMAMIN NOM MAX MIN
A1 0.01 0.06 0.10 0.001
q
b 0.25 0.38 0.50 0.010
c 0.10 0.18 0.26 0.004
D 2.90 3.00 3.10 0.114
E 1.30 1.50 1.70 0.051
e 0.85 0.95 1.05 0.034
L 0.20 0.40 0.60 0.008
H
E
q
MILLIMETERS
0.90 1.00 1.10 0.035
2.50 2.75 3.00 0.099 0.108 0.118
0° 10° 0° 10°
− −
INCHES
NOM MAX
0.039 0.043
0.002 0.004
0.014 0.020
0.007 0.010
0.118 0.122
0.059 0.067
0.037 0.041
0.016 0.024
SOLDERING FOOTPRINT*
2.4
0.094
0.95
0.037
1.9
0.075
0.95
0.037
0.7
0.028
1.0
0.039
SCALE 10:1
ǒ
inches
mm
Ǔ
*For additional information on our Pb−Free strategy and soldering
details, please download the ON Semiconductor Soldering and
Mounting Techniques Reference Manual, SOLDERRM/D.
This product utilizes US Patent #6,646,463 Impedance Emulator Patent issued to Alliance Semiconductor, Dated 11−11 −2003.
ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice
to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability
arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages.
“Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All
operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights
nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications
intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should
Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates,
and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death
associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal
Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.
PUBLICATION ORDERING INFORMATION
LITERATURE FULFILLMENT:
Literature Distribution Center for ON Semiconductor
P.O. Box 5163, Denver, Colorado 80217 USA
Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada
Fax: 303−675−2176 or 800−344−3867 Toll Free USA/Canada
Email: orderlit@onsemi.com
N. American Technical Support: 800−282−9855 Toll Free
USA/Canada
Europe, Middle East and Africa Technical Support:
Phone: 421 33 790 2910
Japan Customer Focus Center
Phone: 81−3−5773−3850
http://onsemi.com
ON Semiconductor Website: www.onsemi.com
Order Literature: http://www.onsemi.com/orderlit
For additional information, please contact your local
Sales Representative
NB2779A/D
8
Loading...