The P2027 is a versatile spread spectrum frequency
modulator designed specifically for digital camera
and other digital video and imaging applications. The
P2027 reduces electromagnetic interference (EMI) at
Block Diagram
MRA SR0 SSON
P2027A
the clock source, which provides system wide
reduction of EMI of all clock dependent signals. The
P2027 allows significant system cost savings by
reducing the number of circuit board layers and
shielding that are traditionally required to pass EMI
regulations.
The P2027 uses the most efficient and optimized
modulation profile approved by the FCC and is
implemented in a proprietary all-digital method.
The P2027 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 P2027 is targeted towards DSC market as well
as other imaging and digital video applications like
DVD and VCD players.
VDD
PLL
Modulation
XIN
XOUT
Crystal
Oscillator
Frequency
Divider
Feedback
Divider
Phase
Detector
Loop Filter
VCO
Output
Divider
ModOUT
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.
November 2006
rev 0.2
Pin Configuration
XIN / CLKIN 1
XOUT 2
8 VDD
7 SRO
P2027A
P2027A
MRA 3
VSS
4
6 ModOUT
5 SSON
Pin Description
Pin#
1
2
3
4
5
6
7
8
Pin Name
XIN/CLK
XOUT
MRA
VSS
SSON
ModOUT
SR0
VDD
Type
I
O
I
P
I
O
I
P
Description
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.
Crystal connection. Input connection for an external crystal. If using an
external reference, this pin must be left unconnected.
Digital logic input used to select Modulation Rate (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 pull-low
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 Power Supply.
General Purpose EMI Reduction IC
Notice: The information in this document is subject to change without notice.
2 of 8
November 2006
rev 0.2
Table-1 Modulation and Spreading Selection
MRA
0
0
1
1
SR0
0
1
0
1
Spread Range
Reserve
+/- 0.30%
+/- 0.20%
+/- 0.60%
Modulation Rate
Reserve
(Fin/10)*34.72 KHz
(Fin/10)*20.83 KHz
(Fin/10)*20.83 KHz
P2027A
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:
P2027 is designed for DSC and digital video and imaging markets and is optimized for 27 MHz under
minimum deviation settings. Selecting P2027’s spread options to MRA=1 and SR0=1 for a 27 MHz input signal
provides a percentage deviation of +/-0.60% (see Table 1) from the reference signal. This results in frequency
on ModOUT being swept from 27.16 MHz to 26.84 MHz at a modulation rate of 56.24 KHz (see Table 1). This
particular example (see the below figure) given here is a new EMI reduction method for DSC applications and is
already gaining popularity among leading manufacturers.
Application Schematic for Digital Still Camera
General Purpose EMI Reduction IC
Notice: The information in this document is subject to change without notice.
3 of 8
November 2006
rev 0.2
Absolute Maximum Ratings
Symbol
VDD, V
IN
T
STG
T
A
T
s
T
J
T
DV
Storage temperature
Operating temperature
Max. Soldering Temperature (10 sec)
Junction Temperature
Static Discharge Voltage (As per JEDEC STD22- A114-B)
P2027A
Parameter
Voltage on any pin with respect to Ground
Rating
-0.5 to +4.6
-65 to +125
0 to 70
260
150
2
Unit
V
°C
°C
°C
°C
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
Symbol
V
IL
V
IH
I
IL
I
IH
I
XOL
I
XOH
V
OL
V
OH
I
DD
I
CC
V
DD
t
ON
Z
OUT
Input Low Voltage
Input High Voltage
Input Low Current (pull-up resistor on inputs FS0, SR0
and MRA)
Input High Current (pull-down resistor on input SSON)
XOUT Output Low Current (@ 0.4V, V
DD
= 3.3V)
XOUT Output High Current (@ 2.5V, V
DD
= 3.3V)
Output Low Voltage (V
DD
= 3.3V, I
OL
= 20 mA)
Output High Voltage (V
DD
= 3.3V, I
OH
= 20 mA)
Static Supply Current
Dynamic Supply Current (3.3V and 15 pF loading)
Operating Voltage
Power Up Time (First locked clock cycle after power up)
Clock Output Impedance
Parameter
Min
GND – 0.3
2.0
-
-
-
-
-
2.5
-
6.0
2.7
Typ
-
-
-
-
3
3
-
-
6.0
7.0
3.3
0.18
50
Max
0.8
V
DD
+ 0.3
-35
35
-
-
0.4
-
-
8.3
3.8
Unit
V
V
µA
µA
mA
mA
V
V
mA
mA
V
ms
Ω
AC Electrical Characteristics
Symbol
f
IN
t
LH
*
t
HL
*
t
JC
t
D
Input Frequency
Output rise time
(Measured at 0.8V to 2.0V)
Output fall time
(Measured at 0.8V to 2.0V)
Jitter (cycle to cycle)
Output duty cycle
Parameter
Min
10
0.7
0.6
-
45
Typ
27
0.9
0.8
-
50
Max
30
1.1
1.0
360
55
Unit
MHz
ns
ns
ps
%
*
t
LH
and t
HL
are measured into a capacitive load of 15pF
General Purpose EMI Reduction IC
Notice: The information in this document is subject to change without notice.
4 of 8
November 2006
rev 0.2
Package Information
P2027A
8-lead (150-mil) SOIC Package
E
H
D
A2
A
θ
e
B
A
1
C
L
D
Dimensions
Symbol
Min
A1
A
A2
B
C
D
E
e
H
L
θ
Inches
Max
0.010
0.069
0.059
0.020
0.010
0.004
0.053
0.049
0.012
0.007
Millimeters
Min
Max
0.10
1.35
1.25
0.31
0.18
4.90 BSC
3.91 BSC
1.27 BSC
6.00 BSC
0.41
0°
1.27
8°
0.25
1.75
1.50
0.51
0.25
0.193 BSC
0.154 BSC
0.050 BSC
0.236 BSC
0.016
0°
0.050
8°
General Purpose EMI Reduction IC
Notice: The information in this document is subject to change without notice.
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