PULSECORE P2779AF-08-ST

P2779A
February 2007
rev 0.2
Low-Cost Notebook EMI Reduction IC
Features
the clock source, which provides system-wide reduction of
•
Provides up to 15dB of EMI suppression
EMI of all clock dependent signals. The P2779A allows
•
FCC approved method of EMI attenuation
significant system cost savings by reducing the number of
•
Generates a 1X low EMI spread spectrum clock of
circuit board layers and shielding that are traditionally
the input frequency
required to pass EMI regulations.
Operates between 20MHz and 38MHz input
The P2779A uses the most efficient and optimized
frequency range
modulation profile approved by the FCC.
External loop filter for spread percentage
The P2779A modulates the output of a single PLL in order
adjustment
to spread the bandwidth of a synthesized clock and, more
•
Spreading ranges from ±0.25% to ±2.5%
importantly,
•
Ultra low cycle-to-cycle jitter
harmonics. This results in significantly lower system EMI
•
Zero-Cycle slip at small deviations
compared to the typical narrow-band signal produced by
•
3.3 V Operating Voltage
oscillators and most frequency generators. Lowering EMI
•
Low power CMOS design
by increasing a signal’s bandwidth is called spread
•
Available in 8-pin SOIC and TSSOP Packages
spectrum clock generation.
•
Available in Industrial temperature operating
•
•
decreases
the
peak
amplitudes
of
its
Applications
range (-40º C to 85º C)
The P2779A is targeted toward mobile 3D graphics chip set
applications.
Product Description
The P2779A is a versatile spread spectrum frequency
modulator designed specifically for mobile and digital
camera and other digital video and imaging applications.
The P2779A reduces electromagnetic interference (EMI) at
Block Diagram
PD
VDD
LF
PLL
Modulation
XIN
Crystal
Oscillator
XOUT
Frequency
Divider
Feedback
Divider
Phase
Detector
Loop
Filter
VCO
Output
Divider
ModOUT
REF
VSS
PulseCore Semiconductor Corporation
1715 S. Bascom Ave Suite 200, Campbell, CA 95008 • Tel: 408-879-9077 • Fax: 408-879-9018
www.pulsecoresemi.com
Notice: The information in this document is subject to change without notice.
P2779A
February 2007
rev 0.2
Pin Configuration
XIN / CLKIN 1
8
XOUT 2
P2779A
VDD
7 REF
PD 3
6 ModOUT
LF 4
5 VSS
Pin Description
Pin#
Pin Name
Type
1
XIN / CLKIN
I
Connect to crystal or clock input.
2
XOUT
O
Crystal output.
3
PD
I
Description
Power-down control pin. Pull low to enable power-down mode.
This pin has an internal pull-up resistor.1
External loop filter for the PLL. By changing the value of the CRC circuit,
the percentage spread can be adjusted accordingly.
(See Loop Filter Selection Table for detail values.)
4
LF
I
5
VSS
P
Ground connection. Connect to system ground.
6
ModOUT
O
Spread spectrum clock output.
7
REF
O
Provides a reference clock output of the input frequency.
8
VDD
P
Connect to +3.3 V.
Note: 1. Connect to VDD if not used.
Loop Filter Selection Table VDD 3.3 V
Pin 4 LF
R1
C1
C2
Input
(MHz)
FS1
FS0
20
21-22
23-24
25-26
27-28
29-30
31-32
33-34
35-36
37-38
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
C1
(pF)
270
270
270
270
270
270
270
270
270
270
BW = ± 0.50%
C2
R1
(pF)
(Ω)
100,000
330
100,000
390
100,000
510
100,000
560
100,000
620
100,000
750
100,000
820
100,000
910
100,000 1,000
100,000 1,200
C1
(pF)
270
270
270
270
270
270
270
270
270
270
BW = ± 0.75%
C2
R1
(pF)
(Ω)
100,000 560
100,000 620
100,000 750
100,000 820
100,000 1,000
100,000 1,100
100,000 1,200
100,000 1,300
100,000 1,500
100,000 1,600
C1
(pF)
270
270
270
270
270
270
270
270
270
270
BW = ± 1.00%
C2
R1
(pF)
(Ω)
100,000 750
100,000 866(1%)
10,000
1,000
12,000
1,200
6,800
1,200
3,900
1,200
12,000
2,200
10,000
2,200
5,600
2,200
3,300
2,200
C1
(pF)
560
560
680
470
330
330
680
390
270
270
BW = ± 1.25%
C2
R1
(pF)
(Ω)
100,000
910
100,000
1,100
6,800
1,200
4,700
1,200
3,300
1,200
3,300
1,500
6,800
2,200
3,900
2,200
2,700
2,200
2,700
2,700
Please contact factory for loop filter values if desired spread settings are not listed.
Low-Cost Notebook EMI Reduction IC
Notice: The information in this document is subject to change without notice.
2 of 8
P2779A
February 2007
rev 0.2
Spread Spectrum Selection
The P2779A performs zero cycle slip when set at low percentage spreading. This prevents any occurrence of system timing
error. 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 that the center frequency is the frequency of the external
reference input on XIN/CLKIN, pin 1.)
The P2779A is designed for PC peripheral, networking, notebook PC, and LCD monitor applications. It is optimized for
operation from 20MHz to 38MHz. The P2779A’s spread percentage selection is determined by the external LF value
specified in the Loop Filter Selection Table. The external LF allows the user to fine tune the spread percentage to optimize
the EMI reduction benefits of the spread spectrum.
Application Schematic
27 MHz
1 XIN/CLKIN VDD 8
VDD
2 XOUT
3 PD
C2
R1
C1
REF 7
0.1µF
+3.3V
ModOUT 6
4 LF
Modulated 27MHz
VSS 5
P2779A
PD selection: Power dissipation can be reduced by completely turning off the IC.
Low-Cost Notebook EMI Reduction IC
Notice: The information in this document is subject to change without notice.
3 of 8
P2779A
February 2007
rev 0.2
Absolute Maximum Ratings
Symbol
Parameter
VDD, VIN
Voltage on any pin with respect to Ground
-0.5 to +4.6
V
Storage temperature
-65 to +125
°C
TA
Operating temperature
-40 to +85
°C
Ts
Max. Soldering Temperature (10 sec)
260
°C
TJ
Junction Temperature
150
°C
2
KV
TSTG
TDV
Rating
Static Discharge Voltage
(As per JEDEC STD22- A114-B)
Unit
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
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
-
60
-
µA
IIH
Input high current
-
0
-
µA
IXOL
XOUT output low current (at 0.4 V, VDD = 3.3V)
-
10
-
mA
IXOH
XOUT output high current (at 2.5 V, VDD = 3.3V)
-
10
-
mA
VOL
Output low voltage (VDD = 3.3V, IOL = 20 mA)
-
-
0.4
V
VOH
Output high voltage (VDD = 3.3V, IOH = 20 mA)
2.5
-
-
V
IDD
Static supply current
-
3
-
mA
ICC
Dynamic supply current
(3.3 V, 25 pF loading, 32 MHz)
-
12
-
mA
VDD
Operating voltage
3.0
3.3
3.6
V
tON
Power-up time (first locked cycle after power up)
-
7
-
mS
Clock output impedance
-
28
-
Ω
ZOUT
AC Electrical Characteristics
Symbol
Min
Typ
Max
Unit
Input frequency
20
-
38
MHz
fOUT
Output frequency
20
-
38
MHz
1
tLH
Output rise time (measured at 0.8 V to 2.0 V)
-
1
-
nS
fIN
tHL
1
Parameter
Output fall time (measured at 2.0 V to 0.8 V)
-
1
-
nS
tJC
Jitter (Cycle to cycle)
-
±175
-
pS
tD
Output duty cycle
45
50
55
%
Note: 1. tLH and tHL are measured into a capacitive load of 15 pF
Low-Cost Notebook EMI Reduction IC
Notice: The information in this document is subject to change without notice.
4 of 8
P2779A
February 2007
rev 0.2
Package Information
8-lead (150-mil) 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°
Note: Controlling dimensions are millimeters
SOIC – 0.074 grams unit weight
Low-Cost Notebook EMI Reduction IC
Notice: The information in this document is subject to change without notice.
5 of 8
P2779A
February 2007
rev 0.2
8-lead Thin Shrunk Small Outline Package (4.40-MM Body)
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°
Note: Controlling dimensions are millimeters
TSSOP – 0.0325 grams unit weight
Low-Cost Notebook EMI Reduction IC
Notice: The information in this document is subject to change without notice.
6 of 8
P2779A
February 2007
rev 0.2
Ordering Information
Part number
P2779AF-08-ST
Marking
P2779AF
Package Type
Temperature
8-Pin SOIC, Tube, Pb Free
Commercial
P2779AF-08-SR
P2779AF
8-Pin SOIC, Tape and Reel, Pb Free
Commercial
P2779AG-08-ST
P2779AG
8-Pin SOIC, Tube, Green
Commercial
P2779AG-08-SR
P2779AG
8-Pin SOIC, Tape and Reel, Green
Commercial
I2779AF-08-ST
I2779AF
8-Pin SOIC, Tube, Pb Free
Industrial
I2779AF-08-SR
I2779AF
8-Pin SOIC, Tape and Reel, Pb Free
Industrial
I2779AG-08-ST
I2779AG
8-Pin SOIC, Tube, Green
Industrial
I2779AG-08-SR
I2779AG
8-Pin SOIC, Tape and Reel, Green
Industrial
P2779AF-08-TT
P2779AF
8-Pin TSSOP, Tube, Pb Free
Commercial
P2779AF-08-TR
P2779AF
8-Pin TSSOP, Tape and Reel, Pb Free
Commercial
P2779AG-08-TT
P2779AG
8-Pin TSSOP, Tube, Green
Commercial
P2779AG-08-TR
P2779AG
8-Pin TSSOP, Tape and Reel, Green
Commercial
I2779AF-08-TT
I2779AF
8-Pin TSSOP, Tube, Pb Free
Industrial
I2779AF-08-TR
I2779AF
8-Pin TSSOP, Tape and Reel, Pb Free
Industrial
I2779AG-08-TT
I2779AG
8-Pin TSSOP, Tube, Green
Industrial
I2779AG-08-TR
I2779AG
8-Pin TSSOP, Tape and Reel, Green
Industrial
Device Ordering Information
P 2 7 7 9 A
F - 0 8 - S T
SR - SOIC, T/R
TT – TSSOP, TUBE
TR - TSSOP, T/R
ST – SOIC, TUBE
Pin Count
F = LEAD FREE AND RoHS COMPLIANT PART
G = GREEN PACKAGE, LEAD FREE, and RoHS
Deviation (%) and Spread option Identifier
DEVICE NUMBER
Flow:
P = Commercial Temperature Range (0°C to 70°C)
I = Industrial Temperature Range (-40°C to 85°C)
Licensed under US patent #5,488,627, #6,646,463 and #5,631,920.
Low-Cost Notebook EMI Reduction IC
Notice: The information in this document is subject to change without notice.
7 of 8
P2779A
February 2007
rev 0.2
PulseCore Semiconductor Corporation
1715 S. Bascom Ave Suite 200
Campbell, CA 95008
Tel: 408-879-9077
Fax: 408-879-9018
www.pulsecoresemi.com
Copyright © PulseCore Semiconductor
All Rights Reserved
Preliminary Information
Part Number: P277A
Document Version: v0.2
Note: This product utilizes US Patent # 6,646,463 Impedance Emulator Patent issued to PulseCore Semiconductor, dated 11-11-2003
© Copyright 2007 PulseCore Semiconductor Corporation. All rights reserved. Our logo and name are trademarks or
registered trademarks of PulseCore Semiconductor. All other brand and product names may be the trademarks of their
respective companies. PulseCore reserves the right to make changes to this document and its products at any time without
notice. PulseCore assumes no responsibility for any errors that may appear in this document. The data contained herein
represents PulseCore’s best data and/or estimates at the time of issuance. PulseCore 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. PulseCore 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 PulseCore 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 PulseCore’s Terms and Conditions of Sale (which are available from
PulseCore). All sales of PulseCore products are made exclusively according to PulseCore’s Terms and Conditions of Sale.
The purchase of products from PulseCore does not convey a license under any patent rights, copyrights; mask works rights,
trademarks, or any other intellectual property rights of PulseCore or third parties. PulseCore 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 PulseCore products in such life-supporting systems implies that the
manufacturer assumes all risk of such use and agrees to indemnify PulseCore against all claims arising from such use.
Low-Cost Notebook EMI Reduction IC
Notice: The information in this document is subject to change without notice.
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