ALSC P2041A-08TT

P2041A
November 2003
rev F
Versatile EMI Reduction IC
Features
ƒ FCC approved method of EMI attenuation
ƒ Provides up to 20 dB of EMI suppression
ƒ Generates a low EMI spread spectrum clock
of the input frequency
ƒ Optimized for 25 MHz to 60MHz input
frequency range
ƒ Internal loop filter minimizes external
components and board space
ƒ 4 selectable spread ranges
ƒ SSON control pin for spread spectrum
enable and disable options
ƒ Characterizes to work with EMI-Lator®, EMC
simulation program.
ƒ Low cycle-to-cycle jitter
ƒ 3.3 V or 5.0 V operating range
ƒ 16 mA output drives
ƒ TTL or CMOS compatible outputs
ƒ Low power CMOS design
ƒ Available in 8 pin SOIC and TSSOP
the clock source which provides system wide
reduction of EMI of all clock dependent signals. The
P2041 allows significant system cost savings by
reducing the number of circuit board layers and
shielding that are traditionally required to pass EMI
regulations.
Product Description
The P2041 is a selectable spread spectrum
frequency modulator designed specifically for PC
peripheral and embedded controller markets .The
P2041 reduces electromagnetic interference (EMI) at
Applications
The P2041 is targeted towards the embedded
controller market and PC peripheral markets
including scanners, MFP’s, printers, PDA, IA , and
GPS devices.
The P2041 uses the most efficient and optimized
modulation profile approved by the FCC and is
implemented in a proprietary all-digital method.
The P2041 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”.
Block Diagram
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.
P2041A
November 2003
rev F
Pin Configuration
Pin Description
Pin#
Pin Name
Type
Description
1
XIN/CLK
I
Connect to crystal or externally generated clock signal.
2
XOUT
SR1
I
I
VSS
SSON
P
I
ModOUT
SR0
O
I
VDD
P
Connect to crystal. No connect if externally generated clock signal is used.
Digital logic input used to select Spreading Range (see Table 1). This pin
has an internal pull-up resistor.
Ground Connection. Connect to system ground.
Digital logic input used to enable Spread Spectrum function (Active Low).
Spread Spectrum function enable when low. This pin has an internal pulllow resistor.
Spread Spectrum Clock Output.
Digital logic input used to select Spreading Range (see Table 1). This pin
has an internal pull-up resistor.
Connect to +3.3V or +5.0V
3
4
5
6
7
8
Table 1 - Spread Range Selection
FS0
SR0
Spreading Range
0
0
+/- 1.50%
Input Frequency
Modulation rate
(Fin/40)*34.72 KHz
0
0
1
+/- 2.50%
(Fin/40)*34.72 KHz
0
1
0
+/- 0.50%
(Fin/40)*34.72 KHz**
1
1
1
+/- 1.00%
(Fin/40)*34.72 KHz**
1
Versatile EMI Reduction IC
Notice: The information in this document is subject to change without notice.
2 of 9
P2041A
November 2003
rev F
Spread spectrum selection
Table 1 illustrates the possible spread spectrum options. The optimal setting should minimize system EMI to the
fullest without affecting system performance. The spreading is described as a percentage deviation of the center
frequency (Note: the center frequency is the frequency of the external reference input on CLKIN, Pin 1).
Example of a typical printer or scanner application that operates on a clock frequency of 40 MHz:
A spreading selection of SR1=1 and SR0=1 provides a percentage deviation of +/-1.00%* (see Table 1) of Fcen.
This results in the frequency on ModOUT being swept from 40.40 MHz to 39.60 MHz at a modulation rate of
40/40*34.72=34.72 KHz (see Table 1). This particular example (see Figure below) given here is a common EMI
reduction method for scanners and has already been implemented by most of the leading manufacturers.
NOTE: Spreading range selection varies from different system manufacturers and their designs. The spreading range of P2041 can be set
to +/-2.5% when working with certain scanner model.
P2041 Application Schematic for Flat-Bed Scanner
Versatile EMI Reduction IC
Notice: The information in this document is subject to change without notice.
3 of 9
P2041A
November 2003
rev F
EMC Software Simulation
By using Alliance Semiconductor’s proprietary EMC simulation software – EMI-lator®, radiated system level EMI
analysis can be made easier to allow a quantitative assessment on Alliance’s EMI reduction products. The
simulation engine of this EMC software has already been characterized to correlate with the electrical
characteristics of Alliance EMI reduction IC’s. The figure below is an example of the simulation result. Please
visit our web site at www.alsc.comfor information on how to obtain a free copy and demonstration of EMI-lator®.
Simulation Result from EMI-lator®
Versatile EMI Reduction IC
Notice: The information in this document is subject to change without notice.
4 of 9
P2041A
November 2003
rev F
Absolute Maximum Ratings
Symbol
VDD, VIN
Parameter
Voltage on any pin with respect to GND
Rating
Unit
-0.5 to + 7.0
V
TSTG
Storage temperature
-65 to +125
°C
TA
Operating temperature
0 to +70
°C
DC Electrical Characteristics
Symbol
Parameter
Min
Typ
Max
Unit
VIL
Input Low Voltage
GND – 0.3
-
0.8
V
VIH
Input High Voltage
2.0
-
VDD + 0.3
V
IIL
Input Low Current (pull-up resistor on inputs SR0, 1)
-
-
-35
µA
IIH
Input High Current (pull-down resistor on input SSON)
-
-
35
µA
-
3
-
mA
-
3
-
mA
-
-
0.4
V
2.5
-
-
V
-
0.6
-
mA
7
8.6
10
mA
2.7
3.3
5.5
V
IXOL
XOUT Output Low Current (@ 0.4V, VDD = 3.3V)
IXOH
XOUT Output High Current (@ 2.5V, VDD = 3.3V)
VOL
Output Low Voltage (VDD=3.3V, IOL = 20 mA)
VOH
IDD
Output High Voltage (VDD=3.3V, IOH = 20 mA)
Static Supply Current
ICC
Dynamic Supply Current (3.3V and 15 pF loading)
VDD
Operating Voltage
AC Electrical Characteristics
Symbol
fIN
Parameter
Input Frequency when
tJC
Output rise time
(Measured at 0.8V to 2.0V)
Output fall time
(Measured at 0.8V to 2.0V)
Jitter (cycle to cycle)
tD
Output duty cycle
tLH*
tHL*
Min
25
Typ
40
Max
60
Unit
MHz
0.7
0.9
1.1
ns
0.6
0.8
1.0
ns
45
50
360
ps
%
55
*tLH and tHL are measured into a capacitive load of 15pF
Versatile EMI Reduction IC
Notice: The information in this document is subject to change without notice.
5 of 9
P2041A
November 2003
rev F
Package Information
Mechanical Package Outline 8-Pin SOIC
Symbol
Dimensions in inches
Dimensions in millimeters
Min
Nor
Max
Min
Nor
Max
A
0.057
0.064
0.071
1.45
1.63
1.80
A1
0.004
0.007
0.010
0.10
0.18
0.25
A2
0.053
0.061
0.069
1.35
1.55
1.75
B
0.012
0.016
0.020
0.31
0.41
0.51
C
0.004
0.006
0.01
0.10
0.15
0.25
D
0.186
0.194
0.202
4.72
4.92
5.12
E
0.148
0.156
0.164
3.75
3.95
4.15
e
0.050 BSC
1.27 BSC
H
0.224
0.236
0.248
5.70
6.00
6.30
L
0.012
0.020
0.028
0.30
0.50
0.70
a
0°
5°
8°
0°
5°
8°
Note: Controlling dimensions are millimeters
Versatile EMI Reduction IC
Notice: The information in this document is subject to change without notice.
6 of 9
P2041A
November 2003
rev F
Mechanical Package Outline 8-Pin TSSOP
Dimensions in inches
Symbol
Min
Nor
A
Max
Dimensions in millimeters
Min
Nor
0.047
A1
0.002
A2
0.031
B
Max
1.10
0.006
0.05
0.041
0.80
0.007
0.012
0.19
0.30
C
0.004
0.008
0.09
0.20
D
0.114
0.118
0.122
2.90
3.00
3.10
E
0.169
0.173
0.177
4.30
4.40
4.50
e
0.039
0.026 BSC
0.15
1.00
1.05
0.65 BSC
H
0.244
0.252
0.260
6.20
6.40
6.60
L
0.018
0.024
0.030
0.45
0.60
0.75
a
0°
5°
8°
0°
5°
8°
Note: Controlling dimensions are millimeters
Versatile EMI Reduction IC
Notice: The information in this document is subject to change without notice.
7 of 9
P2041A
November 2003
rev F
Ordering Codes
Part Number
Marking
Package Type
P2041A-08ST
P2041A
8 PIN SOIC, TUBE
P2041A-08SR
P2041A
8 PIN SOIC, TAPE & REEL
P2041A-08TT
P2041A
8 PIN TSSOP, TUBE
P2041A-08TR
P2041A
8 PIN TSSOP, TAPE & REEL
Qty per reel
Temperature
(°C)
0 TO 70
2,500
0 TO 70
0 TO 70
2,500
0 TO 70
Licensed under US patent Nos 5,488,627 and 5,631,920.
Preliminary datasheet. Specification subject to change without notice.
Versatile EMI Reduction IC
Notice: The information in this document is subject to change without notice.
8 of 9
P2041A
November 2003
rev F
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
Part Number: P2041A
Document Version: F
© 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.
Versatile EMI Reduction IC
Notice: The information in this document is subject to change without notice.
9 of 9