ASM3P2760A
Low Power Peak EMI
Reducing Solution
©2010 SCILLC. All rights reserved. Publication Order Number:
JANUARY 2010 – Rev. 2 ASM3P2760/D
Features
Generates an EMI optimized clock signal at the
output.
Integrated loop filter components.
Operates with a 3.3V / 2.5V Supply.
Operating current less than 4mA.
Low power CMOS design.
Input frequency range: 6MHz to 12MHz for 2.5V.
6MHz to 13MHz for 3.3V.
Generates a 1X low EMI spread spectrum clock of
the input frequency.
Frequency deviation: ±0.65% @ 8MHz.
Available in 6-pin TSOT-23, 8-pin SOIC and
8-pin TSSOP Packages.
Product Description
The ASM3P2760A is a versatile spread spectrum
frequency modulator designed specifically for a wide
range of clock frequencies. The ASM3P2760A reduces
electromagnetic interference (EMI) at the clock source,
allowing system wide reduction of EMI of all clock
dependent signals. The ASM3P2760A 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 ASM3P2760A uses the most efficient and optimized
modulation profile approved by the FCC and is
implemented by using a proprietary all digital method.
The ASM3P2760A 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.‟
Applications
The ASM3P2760A is targeted towards all portable
devices with very low power requirements like MP3
players and digital still cameras.
Key Specifications
Description
Specification
Supply voltages
VDD = 3.3V / 2.5V
Cycle-to-Cycle Jitter
200pS (Max)
Output Duty Cycle
45/55%
Modulation Rate Equation
FIN/256
Frequency Deviation
±0.65% @ 8MHz
Block Diagram
XIN
ModOUT
VSS
Feedback
Divider
Modulation
Phase
Detector
Loop
Filter
VCO
Output
Divider
PLL
VDD
PD
Crystal
Oscillator
XOUT
ASM3P2760A
Rev. 2 | Page 2 of 12 | www.onsemi.com
Pin Configuration (6-pin TSOT-23 Package)
Pin Description
Pin#
Pin Name
Type
Description
1
PD
I
Power-down control pin. Pull low to enable power-down 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 connected either to an external crystal or an external reference clock.
4
VDD
P
Power supply for the entire chip.
5
ModOUT
O
Spread spectrum clock output.
6
VSS
P
Ground connection.
XOUT
1
2
3
4
5
6
ASM3P2760A
PD
XIN / CLKIN
VDD
ModOUT
VSS
ASM3P2760A
Rev. 2 | Page 3 of 12 | www.onsemi.com
Pin Configuration (8-pin SOIC and TSSOP Packages)
Pin Description
Pin#
Pin Name
Type
Description
1
XIN / CLKIN
I
Crystal connection or external reference frequency input. This pin has dual functions. It
can be connected either to an external crystal or an external reference clock.
2
XOUT
O
Crystal connection. If using an external reference, this pin must be left unconnected.
3
PD
I
Power-down control pin. Pull low to enable power-down mode. Connect to VDD if not
used.
4
NC
-
No connect.
5
VSS
P
Ground connection.
6
ModOUT
O
Spread spectrum clock output.
7
NC
-
No connect.
8
VDD
P
Power supply for the entire chip.
Modulation Profile
Specification
Description
Specification
Frequency Range
For 2.5V Supply
6MHz < CLKIN < 12MHz
For 3.3V Supply
6MHz < CLKIN < 13MHz
Modulation Equation
FIN/256
Frequency Deviation
±0.65% @ 8MHz
XIN / CLKIN
VSS
ModOUT
NC
XOUT
1
2
3
4
5
6
7
8
ASM3P2760A
PD
NC
VDD
ASM3P2760A
Rev. 2 | Page 4 of 12 | www.onsemi.com
Absolute Maximum Ratings
Symbol
Parameter
Rating
Unit
VDD, VIN
Voltage on any pin with respect to Ground
-0.5 to +4.6
V
TSTG
Storage temperature
-65 to +125
°C
TA
Operating temperature
-40 t0 +85
°C
Ts
Max. Soldering Temperature (10 sec)
260
°C
TJ
Junction Temperature
150
°C
TDV
Static Discharge Voltage
(As per JEDEC STD22- A114-B)
2
KV
Note: These are stress ratings only and are not implied for functional use. Exposure to absolute maximum ratings for prolonged periods of time may affect
device reliability.
DC Electrical Characteristics for 2.5V Supply
(Test condition: All parameters are measured at room temperature (+25°C) unless otherwise stated.)
Symbol
Parameter
Min
Typ
Max
Unit
VIL
Input low voltage
VSS-0.3
-
0.8
V
VIH
Input high voltage
2.0
-
VDD+0.3
V
IIL
Input low current
-
-
-35
µA
IIH
Input high current
-
-
35
µA
IXOL
XOUT output low current (@ 0.5V, VDD = 2.5V)
-
3
-
mA
IXOH
XOUT output high current (@ 1.8V, VDD = 2.5V)
-
3
-
mA
VOL
Output low voltage (VDD = 2.5V, IOL = 8mA)
-
-
0.6
V
VOH
Output high voltage (VDD = 2.5V, IOH = 8mA)
1.8
-
-
V
IDD
Static supply current1
-
-
10
µA
ICC
Dynamic supply current (2.5V, 8MHz and no load)
-
2.5
-
mA
VDD
Operating Voltage
2.375
2.5
2.625
V
tON
Power-up time (first locked cycle after power-up)2
-
-
5
mS
ZOUT
Output impedance
-
50
-
Ω
Notes: 1. XIN / CLKIN pin and PD pin are pulled low.
2. VDD and XIN / CLKIN input are stable, PD pin is made high from low.
AC Electrical Characteristics for 2.5V Supply
Symbol
Parameter
Min
Typ
Max
Unit
CLKIN
Input frequency
6
-
12
MHz
ModOUT
Output frequency
6
-
12
MHz
fd
Frequency Deviation
Input Frequency = 6MHz
-
±1.0
-
%
Input Frequency = 12MHz
-
±0.45
-
tLH1
Output rise time (measured from 0.7V to 1.7V)
0.4
1.2
1.4
nS
tHL1
Output fall time (measured from 1.7V to 0.7V)
0.4
0.9
1.1
nS
tJC
Jitter (cycle-to-cycle)
-
-
200
pS
tD
Output duty cycle
45
50
55
%
Note: 1. tLH and tHL are measured into a capacitive load of 15pF.
ASM3P2760A
Rev. 2 | Page 5 of 12 | www.onsemi.com
DC Electrical Characteristics for 3.3V Supply
(Test condition: All parameters are measured at room temperature (+25°C) unless otherwise stated.)
Symbol
Parameter
Min
Typ
Max
Unit
VIL
Input low voltage
VSS-0.3
-
0.8
V
VIH
Input high voltage
2.0
-
VDD+0.3
V
IIL
Input low current
-
-
-35
µA
IIH
Input high current
-
-
35
µA
IXOL
XOUT output low current (@ 0.4V, VDD = 3.3V)
-
3
-
mA
IXOH
XOUT output high current (@ 2.5V, VDD = 3.3V)
-
3
-
mA
VOL
Output low voltage (VDD = 3.3 V, IOL = 8mA)
-
-
0.4
V
VOH
Output high voltage (VDD = 3.3 V, IOH = 8mA)
2.5
-
-
V
IDD
Static supply current1
-
-
10
µA
ICC
Dynamic supply current (3.3V, 8MHz and no load)
-
3.0
-
mA
VDD
Operating Voltage
2.7
3.3
3.6
V
tON
Power-up time (first locked cycle after power up)2
-
-
5
mS
ZOUT
Output impedance
-
45
-
Ω
Notes: 1. XIN / CLKIN pin and PD pin are pulled low.
2. VDD and XIN / CLKIN input are stable; PD pin is made high from low.
AC Electrical Characteristics for 3.3V Supply
Symbol
Parameter
Min
Typ
Max
Unit
CLKIN
Input frequency
6
-
13
MHz
ModOUT
Output frequency
6
-
13
MHz
fd
Frequency Deviation
Input Frequency = 6MHz
-
±1.0
-
%
Input Frequency = 13MHz
-
±0.4
-
tLH1
Output rise time (measured at 0.8V to 2.0V)
0.5
1.3
1.5
nS
tHL1
Output fall time (measured at 2.0V to 0.8V)
0.4
1.0
1.2
nS
tJC
Jitter (cycle-to-cycle)
-
-
200
pS
tD
Output duty cycle
45
50
55
%
Note: 1. tLH and tHL are measured into a capacitive load of 15pF.
ASM3P2760A
Rev. 2 | Page 6 of 12 | www.onsemi.com
Typical Crystal Oscillator Circuit
Typical Crystal Specifications
Fundamental AT cut parallel resonant crystal
Nominal frequency
8.000MHz
Frequency tolerance
±50ppm or better at 25°C
Operating temperature range
-25°C to +85°C
Storage temperature
-40°C to +85°C
Load capacitance
18pF
Shunt capacitance
7pF maximum
ESR
25
R1 = 510Ω
C1 = 27pF
C2 = 27pF
Crystal
ASM3P2760A
Rev. 2 | Page 7 of 12 | www.onsemi.com
Package Information
6-pin TSOT-23 Package
Symbol
Dimensions
Inches
Millimeters
Min
Max
Min
Max
A
0.04
1.00
A1
0.00
0.004
0.00
0.10
A2
0.033
0.036
0.84
0.90
b
0.012
0.02
0.30
0.50
H
0.005 BSC
0.127 BSC
D
0.114 BSC
2.90 BSC
B
0.06 BSC
1.60 BSC
e
0.0374 BSC
0.950 BSC
C
0.11 BSC
2.80 BSC
L
0.0118
0.02
0.30
0.50
θ
0°
4°
0°
4°
ASM3P2760A
Rev. 2 | Page 8 of 12 | www.onsemi.com
8-Pin SOIC Package
D
EH
D
A1
A2 A
L
C
B
e
Symbol
Dimensions
Inches
Millimeters
Min
Max
Min
Max
A1
0.004
0.010
0.10
0.25
A
0.053
0.069
1.35
1.75
A2
0.049
0.059
1.25
1.50
B
0.012
0.020
0.31
0.51
C
0.007
0.010
0.18
0.25
D
0.193 BSC
4.90 BSC
E
0.154 BSC
3.91 BSC
e
0.050 BSC
1.27 BSC
H
0.236 BSC
6.00 BSC
L
0.016
0.050
0.41
1.27
θ
0°
8°
0°
8°
ASM3P2760A
Rev. 2 | Page 9 of 12 | www.onsemi.com
E
H
A
A1
A2
D
B
C
L
e
8-Pin TSSOP Package
Symbol
Dimensions
Inches
Millimeters
Min
Max
Min
Max
A
0.043
1.10
A1
0.002
0.006
0.05
0.15
A2
0.033
0.037
0.85
0.95
B
0.008
0.012
0.19
0.30
C
0.004
0.008
0.09
0.20
D
0.114
0.122
2.90
3.10
E
0.169
0.177
4.30
4.50
e
0.026 BSC
0.65 BSC
H
0.252 BSC
6.40 BSC
L
0.020
0.028
0.50
0.70
θ
0°
8°
0°
8°
ASM3P2760A
Rev. 2 | Page 10 of 12 | www.onsemi.com
Ordering Information
Part Number
Marking
Package Type
Temperature
ASM3P2760AF-06OR
E4LL
6-Pin TSOT-23, TAPE & REEL, Pb Free
Commercial
ASM3P2760AF-08TT
3P2760AF
8-Pin TSSOP, TUBE, Pb Free
Commercial
ASM3P2760AF-08TR
3P2760AF
8-Pin TSSOP, TAPE & REEL, Pb Free
Commercial
ASM3P2760AF-08ST
3P2760AF
8-Pin SOIC, TUBE, Pb Free
Commercial
ASM3P2760AF-08SR
3P2760AF
8-Pin SOIC, TAPE & REEL, Pb Free
Commercial
ASM3P2760AG-06OR
E3LL
6-Pin TSOT-23, TAPE & REEL, Green
Commercial
ASM3P2760AG-08TT
3P2760AG
8-Pin TSSOP, TUBE, Green
Commercial
ASM3P2760AG-08TR
3P2760AG
8-Pin TSSOP, TAPE & REEL, Green
Commercial
ASM3P2760AG-08ST
3P2760AG
8-Pin SOIC, TUBE, Green
Commercial
ASM3P2760AG-08SR
3P2760AG
8-Pin SOIC, TAPE & REEL, Green
Commercial
ASM3I2760AF-06OR
E5LL
6-Pin TSOT-23, TAPE & REEL, Pb Free
Industrial
ASM3I2760AF-08TT
3I2760AF
8-Pin TSSOP, TUBE, Pb Free
Industrial
ASM3I2760AF-08TR
3I2760AF
8-Pin TSSOP, TAPE & REEL, Pb Free
Industrial
ASM3I2760AF-08ST
3I2760AF
8-Pin SOIC, TUBE, Pb Free
Industrial
ASM3I2760AF-08SR
3I2760AF
8-Pin SOIC, TAPE & REEL, Pb Free
Industrial
ASM3I2760AG-06OR
E6LL
6-Pin TSOT-23, TAPE & REEL, Green
Industrial
ASM3I2760AG-08TT
3I2760AG
8-Pin TSSOP, TUBE, Green
Industrial
ASM3I2760AG-08TR
3I2760AG
8-Pin TSSOP, TAPE & REEL, Green
Industrial
ASM3I2760AG-08ST
3I2760AG
8-Pin SOIC, TUBE, Green
Industrial
ASM3I2760AG-08SR
3I2760AG
8-Pin SOIC, TAPE & REEL, Green
Industrial
ASM3P2760A
Rev. 2 | Page 11 of 12 | www.onsemi.com
Device Ordering Information
A S M 3 P 2 7 6 0 A F - 0 8 T R
Licensed under US Patent #5,488,627 and #5,631,921.
O = TSOT23 U = MSOP J=TSOT26
S = SOIC E = TQFP
T = TSSOP L = LQFP
A = SSOP U = MSOP
V = TVSOP P = PDIP
B = BGA D = QSOP
Q = QFN X = SC-70
DEVICE PIN COUNT
X= Automotive I= Industrial P or n/c = Commercial
(-40C to +125C) (-40C to +85C) (0C to +70C)
1 = Reserved 6 = Power Management
2 = Non PLL based 7 = Power Management
3 = EMI Reduction 8 = Power Management
4 = DDR support products 9 = Hi Performance
5 = STD Zero Delay Buffer 0 = Reserved
ON Semiconductor Mixed Signal Product
PART NUMBER
F = LEAD FREE AND RoHS COMPLIANT PART
G = GREEN PACKAGE, LEAD FREE, and RoHS
R = Tape & Reel, T = Tube or Tray
ASM3P2760A
Note: This product utilizes US Patent #6,646,463 Impedance Emulator Patent issued to PulseCore 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. U.S Patent Pending; Timing-Safe
and Active Bead are trademarks of PulseCore Semiconductor, a wholly owned subsidiary of ON Semiconductor. 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
ON Semiconductor Website:
www.onsemi.com
Order Literature: http://www.onsemi.com/orderlit
For additional information, please contact your
local Sales Representative