ALSC ASM3P2474AF-08TT

ASM3P2474A
October 2005
rev 1.0
Low Power Peak EMI Reducing Solution
Features
ƒ
The ASM3P2474A uses the most efficient and optimized
modulation profile approved by the FCC and is
Generates an EMI optimized clock signal at the
implemented by using a proprietary all digital method.
output.
ƒ
Integrated loop filter components.
ƒ
Operates with a 3.3V Supply.
ƒ
Operating current less than 6mA.
ƒ
Low power CMOS design.
ƒ
Input frequency range : 13MHz to 30MHz
ƒ
Generates a 1X and 2X low EMI spread spectrum
The ASM3P2474A 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
clock of the input frequency.
ƒ
Output Frequency Selection through FSEL pin
ƒ
Frequency deviation : -1.5% (Typ) @25MHz
ƒ
Available in 6-pin TSOT-23, 8-pin SOIC and 8-pin
EMI by increasing a signal’s bandwidth is called ‘spread
spectrum clock generation’.
: -1.5% (Typ) @50MHz
Applications
TSSOP packages.
The ASM3P2474A is targeted towards all portable
devices with very low power requirements like MP3
Product Description
players and digital still cameras.
The ASM3P2474A is a versatile spread spectrum
frequency modulator designed specifically for a wide
range of clock frequencies. The ASM3P2474A reduces
electromagnetic interference (EMI) at the clock source,
Key Specifications
Description
Specification
Supply voltages
VDD = 3.3V ± 0.3V
dependent signals. The ASM3P2474A allows significant
Cycle-to-Cycle Jitter
200pS (Typ)
system cost savings by reducing the number of circuit
Output Duty Cycle
45/55% (worst case)
board layers, ferrite beads and shielding that are
Modulation Rate Equation
FIN/640
traditionally required to pass EMI regulations.
Frequency
Deviation
allowing system wide reduction of EMI of
Block Diagram
all clock
FSEL=0
-1.5% (Typ) @ 50MHz
FSEL=1
-1.5% (Typ) @ 25MHz
FSEL
VDD
PLL
Modulation
XIN/CLKIN
XOUT
Crystal
Oscillator
Frequency
Divider
Feedback
Divider
Phase
Detector
Loop
Filter
VCO
Output
Divider
VSS
Alliance Semiconductor
2575 Augustine Drive • Santa Clara, CA • Tel: 408.855.4900 • Fax: 408.855.4999 • www.alsc.com
Notice: The information in this document is subject to change without notice.
ModOUT
ASM3P2474A
October 2005
rev 1.0
Pin Configuration (6-pin TSOT- 23 Package)
FSEL
1
XOUT
2
6 VSS
ASM3P2474A
XIN / CLKIN 3
5
ModOUT
4
VDD
Pin Description
Pin#
Pin Name
Type
Description
1
FSEL
I
Selection Pin for 1X and 2X Output Frequency Options. Please refer the table
“Frequency Selection Options” for further details
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.
Pin Configuration (8-pin SOIC and TSSOP Packages)
XIN / CLKIN
1
8
VDD
XOUT
2
7
NC
FSEL 3
6
ModOUT
4
5
VSS
NC
ASM3P2474A
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
FSEL
I
Selection Pin for 1X and 2X Output Frequency Options. Please refer the table
“Frequency Selection Options” for further details
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.
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
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ASM3P2474A
October 2005
rev 1.0
Modulation Profile
Specifications
Description
Specification
Frequency Range
13MHz < CLKIN < 30MHz
Modulation Equation
FIN/640
Frequency Deviation
FSEL=0
-1.5% (Typ) @ 50MHz
FSEL=1
-1.5% (Typ) @ 25MHz
Frequency Selection Options
FSEL Pin
Input Frequency (MHz)
Output Frequency (MHz)
0
13-30
26-60
1
13-30
13-30
Absolute Maximum Ratings
Symbol
Parameter
VDD, VIN
TSTG
Rating
Unit
Voltage on any pin with respect to Ground
-0.5 to +7.0
V
Storage temperature
-65 to +125
°C
TA
Operating temperature
0 to 70
°C
Ts
Max. Soldering Temperature (10 sec)
260
°C
TJ
Junction Temperature
150
°C
2
KV
TDV
Static Discharge Voltage
(As per JEDEC STD22- A114-B)
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.
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
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ASM3P2474A
October 2005
rev 1.0
DC Electrical Characteristics
(Test condition: All parameters are measured at room temperature (+25°C) unless otherwise stated)
Symbol
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
Parameter
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 = 3.3V, IOL = 8mA)
-
-
0.4
V
VOH
Output high voltage (VDD = 3.3V, IOH = 8mA)
2.5
-
-
V
IDD
Static supply current*
Dynamic supply current
(3.3V, 25MHz and no load and FSEL=1)
Operating voltage
-
1.6
-
mA
-
4.0
-
mA
3.0
3.3
3.6
V
ICC
VDD
tON
ZOUT
Power-up time (first locked cycle after power-up)
-
-
5
mS
Output impedance
-
45
-
Ω
* XIN /CLKIN pin is pulled low
AC Electrical Characteristics
Symbol
CLKIN
Parameter
Input frequency
FSEL=0
FSEL=1
Output Frequency =
Output Frequency =
Output Frequency =
Output Frequency =
Min
Typ
Max
Unit
13
26
13
-
-1.8
-0.9
-1.8
-0.9
30
60
30
-
MHz
0.85
1.1
nS
ModOUT
Output frequency
fd
Frequency Deviation
fd
Frequency Deviation
tLH*
Output rise time (measured from 0.8 to 2.0V)
0.4
tHL *
Output fall time (measured at 2.0V to 0.8V)
0.3
0.7
0.9
nS
tJC
Jitter (cycle to cycle)
-
200
-
pS
tD
Output duty cycle
45
50
55
%
13MHz
30MHz
26MHz
60MHz
MHz
%
%
*tLH and tHL are measured into a capacitive load of 15pF
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
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ASM3P2474A
October 2005
rev 1.0
Typical Crystal Oscillator Circuit
Crystal
R1 = 510Ω
C1 = 27 pF
C2 = 27 pF
Typical Crystal Specifications
Fundamental AT cut parallel resonant crystal
Nominal frequency
25MHz
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
18pF
Shunt capacitance
7pF maximum
ESR
25 Ω
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
5 of 10
ASM3P2474A
October 2005
rev 1.0
Package Information
6-pin TSOT-23 Package
Dimensions
Symbol
Inches
Min
A
Max
Millimeters
Min
Max
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°
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
6 of 10
ASM3P2474A
October 2005
rev 1.0
8-Pin SOIC Package
H
E
D
A2
A
C
A1
D
θ
e
L
B
Dimensions
Symbol
Inches
Min
Max
Millimeters
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°
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
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ASM3P2474A
October 2005
rev 1.0
8-Pin TSSOP Package
H
E
D
A2
A
C
θ
e
A1
L
B
Dimensions
Symbol
Inches
Min
Millimeters
Max
A
Min
Max
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°
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
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ASM3P2474A
October 2005
rev 1.0
Ordering Information
Part Number
Marking
Package Type
Temperature
ASM3P2474AF-06OR
W4LL
6-Pin TSOT-23, TAPE & REEL, Pb Free
Commercial
ASM3P2474AF-08TT
3P2474AF
8-Pin TSSOP, TUBE, Pb Free
Commercial
ASM3P2474AF-08TR
3P2474AF
8-Pin TSSOP, TAPE & REEL, Pb Free
Commercial
ASM3P2474AF-08ST
3P2474AF
8-Pin SOIC, TUBE, Pb Free
Commercial
ASM3P2474AF-08SR
3P2474AF
8-Pin SOIC, TAPE & REEL, Pb Free
Commercial
ASM3P2474AG-06OR
W3LL
6-Pin TSOT-23, TAPE & REEL, Green
Commercial
ASM3P2474AG-08TT
3P2474AG
8-Pin TSSOP, TUBE, Green
Commercial
ASM3P2474AG-08TR
3P2474AG
8-Pin TSSOP, TAPE & REEL, Green
Commercial
ASM3P2474AG-08ST
3P2474AG
8-Pin SOIC, TUBE, Green
Commercial
ASM3P2474AG-08SR
3P2474AG
8-Pin SOIC, TAPE & REEL, Green
Commercial
Device Ordering Information
A S M 3 P 2 4 7 4 A F - 0 8 T R
R = Tape & reel, T = Tube or Tray
O = SOT
S = SOIC
T = TSSOP
A = SSOP
V = TVSOP
B = BGA
Q = QFN
U = MSOP
E = TQFP
L = LQFP
U = MSOP
P = PDIP
D = QSOP
X = SC-70
DEVICE PIN COUNT
F = LEAD FREE AND RoHS COMPLIANT PART
G = GREEN PACKAGE
PART NUMBER
X= Automotive
I= Industrial
P or n/c = Commercial
(-40C to +125C) (-40C to +85C)
(0C to +70C)
1 = Reserved
2 = Non PLL based
3 = EMI Reduction
4 = DDR support products
5 = STD Zero Delay Buffer
6 = Power Management
7 = Power Management
8 = Power Management
9 = Hi Performance
0 = Reserved
ALLIANCE SEMICONDUCTOR MIXED SIGNAL PRODUCT
Licensed under U.S Patent Nos 5,488,627 and 5,631,921
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
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ASM3P2474A
October 2005
rev 1.0
Alliance Semiconductor Corporation
2575 Augustine Drive,
Santa Clara, CA 95054
Tel# 408-855-4900
Fax: 408-855-4999
www.alsc.com
Copyright © Alliance Semiconductor
All Rights Reserved
Preliminary Information
Part Number: ASM3P2474A
Document Version: v1.0
Note: This product utilizes US Patent # 6,646,463 Impedance Emulator Patent issued to Alliance Semiconductor, dated 11-11-2003
© Copyright 2003 Alliance Semiconductor Corporation. All rights reserved. Our three-point logo, our name and Intelliwatt are
trademarks or registered trademarks of Alliance. All other brand and product names may be the trademarks of their respective
companies. Alliance reserves the right to make changes to this document and its products at any time without notice. Alliance
assumes no responsibility for any errors that may appear in this document. The data contained herein represents Alliance's
best data and/or estimates at the time of issuance. Alliance reserves the right to change or correct this data at any time,
without notice. If the product described herein is under development, significant changes to these specifications are possible.
The information in this product data sheet is intended to be general descriptive information for potential customers and users,
and is not intended to operate as, or provide, any guarantee or warrantee to any user or customer. Alliance does not assume
any responsibility or liability arising out of the application or use of any product described herein, and disclaims any express or
implied warranties related to the sale and/or use of Alliance products including liability or warranties related to fitness for a
particular purpose, merchantability, or infringement of any intellectual property rights, except as express agreed to in Alliance's
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according to Alliance's Terms and Conditions of Sale. The purchase of products from Alliance does not convey a license under
any patent rights, copyrights; mask works rights, trademarks, or any other intellectual property rights of Alliance or third
parties. Alliance does not authorize its products for use as critical components in life-supporting systems where a malfunction
or failure may reasonably be expected to result in significant injury to the user, and the inclusion of Alliance products in such
life-supporting systems implies that the manufacturer assumes all risk of such use and agrees to indemnify Alliance against all
claims arising from such use.
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
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