ALSC ASM3P5821A

October 2003
ASM3P5821A
rev 1.0
The ASM3P5821A reduces electromagnetic interference
Features
(EMI) at the clock source, allowing system wide reduction
FCC approved method of EMI attenuation.
Generates a 1X low EMI spread spectrum clock of
the input frequency.
Internal loop filter minimizes external components
and board space.
Frequency deviation: -1.5%
implemented in a proprietary all digital method.
TTL or CMOS compatible inputs and outputs.
Ultra-low power CMOS design.
The ASM3P5821A modulates the output of a single PLL
TBD mA @ 3.3V, 25MHz
in order to “spread” the bandwidth of a synthesized clock,
TBD mA @ 3.3V, 31MHz
compatible
with
Cypress
that are traditionally required to pass EMI regulations.
modulation profile approved by the FCC and is
3.3V operating voltage.
Pinout
ferrite beads, shielding and other passive components
The ASM3P5821A uses the most efficient and optimized
Low inherent cycle-to-cycle jitter.
o
down stream clock and data dependent
signals. The ASM3P5821A allows significant system cost
savings by reducing the number of circuit board layers
Input frequency range: 20MHz –34MHz.
o
of EMI of
CY25811.
Products are available for industrial temperature
range.
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
Available in 8-pin SOIC and TSSOP.
EMI by increasing a signal’s bandwidth is called ‘spread
Product Description
spectrum clock generation’.
The ASM3P5821A is a versatile spread spectrum
frequency modulator designed specifically for input clock
Applications
frequencies in the range of 20MHz – 34MHz. The
ASM3P5821A can generate an EMI reduced clock from
The ASM3P5821A is targeted towards EMI management
crystal,
for high speed digital applications such as PC peripheral
ceramic
resonator,
or
system
clock.
The
ASM3P5821A offers a percentage deviation of –1.5%.
devices, consumer electronics and embedded controller
systems.
VDD
Block Diagram
PLL
Modulation
XIN
Crystal
Oscillator
Frequency
Divider
XOUT
Feedback
Divider
Phase
Detector
Loop
Filter
VCO
Output
Divider
MODOUT
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.
October 2003
ASM3P5821A
rev 1.0
Pin Configuration
XIN
1
VSS
2
8
XOUT
7
VDD
ASM3P5821A
NC
3
6
NC
NC
4
5
ModOUT
Pin Description
Pin#
Pin Name
Type
1
XIN
I
Crystal connection or external reference frequency input. This pin has dual
functions. It can be connected to either an external crystal or an external
reference clock.
2
VSS
P
Ground to entire chip.
3
NC
No Connect.
4
NC
No Connect.
5
MODOUT
6
NC
7
VDD
P
Power supply for the entire chip (3.3V).
8
XOUT
O
Crystal connection. If using an external reference clock, this pin must be left
unconnected.
O
Description
Spread spectrum low EMI output.
No Connect.
Low Power EMI Reduction IC
Notice: The information in this document is subject to change without notice.
2 of 7
October 2003
ASM3P5821A
rev 1.0
Absolute Maximum Ratings
Symbol
Parameter
VDD, VIN
Voltage on any pin with respect to GND
TSTG
Storage temperature
TA
Operating temperature
Rating
Unit
-0.5 to + 7.0
V
-65 to +125
°C
0 to 70
°C
Note: These are stress ratings only and functional operation is not implied. Exposure to absolute maximum
ratings for extended periods may affect device reliability.
DC Electrical Characteristics
Symbol
Parameter
Min
Typ
Max
Unit
VIL
Input low voltage
GND – 0.3
-
TBD
V
VIH
Input high voltage
TBD
-
VDD + 0.3
V
IIL
Input low current
TBD
µA
IIH
Input high current
TBD
µA
IXOL
XOUT output low current (@0.4V, VDD=3.3V)
TBD
mA
IXOH
XOUT output high current (@ 2.5V, VDD=3.3V)
TBD
mA
VOL
Output low voltage (VDD = 3.3V, IOL = 4mA)
TBD
V
VOH
Output high voltage (VDD = 3.3V, IOH = 4mA)
TBD
V
ICC
Dynamic supply current normal mode (3.3V and 10pF
loading)
TBD
mA
IDD
Static supply current standby mode
VDD
Operating voltage
tON
ZOUT
µA
TBD
3.3
TBD
V
Power up time (first locked clock cycle after power up)
-
TBD
-
mS
Clock out impedance
-
TBD
-
Ω
Low Power EMI Reduction IC
Notice: The information in this document is subject to change without notice.
3 of 7
October 2003
ASM3P5821A
rev 1.0
AC Electrical Characteristics
Symbol
Parameter
Min
Typ
Max
Unit
XIN
Input frequency
20
25/31
34
MHz
MODOUT
Output frequency
20
25/31
34
MHz
tLH*
Output rise time (measured at 0.8V to 2.0V)
ns
tHL*
Output fall time (measured at 2.0V to 0.8V)
ns
tJC
Jitter (cycle to cycle)
-
-
TBD
ps
tD
Output duty cycle
-
TBD
-
%
*tLH and tHL are measured into a capacitive load of 15pF
Low Power EMI Reduction IC
Notice: The information in this document is subject to change without notice.
4 of 7
October 2003
ASM3P5821A
rev 1.0
Package Information
8-Pin SOIC
H
E
D
A2
A
C
A1
D
θ
e
L
B
Symbol
Dimensions in inches
Dimensions in millimeters
Min
Max
Min
Max
A
0.057
0.071
1.45
1.80
A1
0.004
0.010
0.10
0.25
A2
0.053
0.069
1.35
1.75
B
0.012
0.020
0.31
0.51
C
0.004
0.01
0.10
0.25
D
0.186
0.202
4.72
5.12
E
0.148
0.164
3.75
4.15
e
0.050 BSC
1.27 BSC
H
0.224
0.248
5.70
6.30
L
0.012
0.028
0.30
0.70
0°
8°
0°
8°
Low Power EMI Reduction IC
Notice: The information in this document is subject to change without notice.
5 of 7
October 2003
ASM3P5821A
rev 1.0
8-Pin TSSOP
H
E
D
A2
A
C
θ
e
A1
L
B
Dimensions in inches
Symbol
Min
A
0.047
A1
0.002
0.006
0.05
0.15
A2
0.031
0.041
0.80
1.05
B
0.007
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
Max
Dimensions in millimeters
Min
Max
1.10
0.026 BSC
0.65 BSC
H
0.244
0.260
6.20
6.60
L
0.018
0.030
0.45
0.75
θ
0°
8°
0°
8°
Low Power EMI Reduction IC
Notice: The information in this document is subject to change without notice.
6 of 7
October 2003
ASM3P5821A
rev 1.0
Alliance Semiconductor Corporation
2595, 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: ASM3P5821A
Document Version: v1.0
© 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 Terms and Conditions of Sale (which are available from Alliance).
All sales of Alliance products are made exclusively 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 EMI Reduction IC
Notice: The information in this document is subject to change without notice.
7 of 7