P2782AG-08TR [ONSEMI]
156MHz, OTHER CLOCK GENERATOR, PDSO8, GREEN, TSSOP-8;
| 型号： | P2782AG-08TR |
| 厂家： | 
ONSEMI |
| 描述： | 156MHz, OTHER CLOCK GENERATOR, PDSO8, GREEN, TSSOP-8 时钟 ISM频段 光电二极管 外围集成电路 晶体 |
| 文件： | 总8页 (文件大小：210K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
P2781/82/84
General Purpose EMI
Reduction IC
Features
• Provides up to 15dB of EMI suppression
source, which provides system wide reduction of EMI of all
clock dependent signals. The P278xA allows significant
system cost savings by reducing the number of circuit
board layers and shielding that are traditionally required to
pass EMI regulations.
• FCC approved method of EMI attenuation
• Generates a 1X, 2X, and 4X low EMI spread spectrum
clock of the input frequency
• Input frequency range from 3 to 78MHz
• External loop filter for spread % adjustment
• Spreading ranges from ±0.25% to ±5.0%
• Ultra low cycle-to-cycle jitter
The P278xA uses the most efficient and optimized
modulation profile approved by the FCC. The P278xA
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 result 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.
• Zero-cycle slip
• 3.3V operating voltage range
• Ultra-low power CMOS design
• P278xA is available in an 8 pin SOIC Package
Product Description
The P278xA is a versatile spread spectrum frequency
modulator designed specifically for digital camera and other
digital video and imaging applications. The P278xA
reduces electromagnetic interference (EMI) at the clock
Applications
The P278xA is targeted towards MFP, xDSL, fax modem,
set-top box, USB controller, DSC, and embedded systems.
Block Diagram
FS0
FS1
LF
VDD
PLL
Modulation
XIN / CLKIN
XOUT
Frequency
Divider
Crystal
Oscillator
Output
Divider
Phase
Detector
VCO
Feedback
Divider
ModOUT
VSS
©2010 SCILLC. All rights reserved.
NOVEMBER 2010 – Rev. 2.1
Publication Order Number:
P2781/82/84
P2781/82/84
Pin Configuration
XIN / CLKIN
XOUT
1
2
3
4
8
7
6
5
VDD
FS0
P278xA
ModOUT
VSS
FS1
LF
Standard pin Configuration offered in both
8 pin SOIC Packages.
Pin Description (P278xA)
Pin#
Pin Name
Type
Description
Connect to crystal or clock input. This pin has dual functions. It can be connected
either to an external crystal or an external reference clock.
Crystal connection. If using an external reference, this pin must be left
unconnected.
Digital logic input used to select input frequency range (see the Input Frequency
Selection Table). This pin has an internal pull-up resistor.
External Loop Filter for the PLL. By changing the value of the CRC circuit, the
percentage spread can be adjusted accordingly. See the Loop Filter Selection
Table for detail value.
1
XIN/CLKIN
I
2
3
XOUT
FS1
O
I
4
LF
I
5
6
VSS
I
Ground Connection. Connect to system ground.
Spread Spectrum Clock Output.
ModOUT
O
Digital logic input used to select input frequency range (see the Input Frequency
Selection Table). This pin has an internal pull-up resistor.
7
8
FS0
I
VDD
P
Connect to +3.3 V
Input Frequency Selection Table
Output Frequency Scaling (MHz)
Modulation Rate (KHz)
FS1
FS0
Input (MHz)
P2781A
P2782A
P2784A
0
0
1
1
0
1
0
1
3 to 9
3 to 9
6 to 18
12 to 36
Fin / 128
Fin / 256
Fin / 512
Fin / 1024
10 to 19
20 to 38
39 to 78
10 to 19
20 to 38
39 to 78
20 to 38
40 to 76
78 to 156
40 to 76
80 to 152
156 to 312
Rev. 2 | Page 2 of 8 | www.onsemi.com
P2781/82/84
Loop Filter Selection Table VDD 3.3V
Contact ON Semiconductor for loop values that are not listed in the table and for
Component selection values for industrial and automotive temperatures.
BW = ±0.50%1
BW = ±0.75%1
BW = ±1.00%1
BW = ±1.25%1
Input
MHz
FS1 FS0
C1
(pF)
C2
(pF)
R1
C1
C2
(pF)
R1
C1
C2
(pF)
R1
(ohm)
C1
(pF)
C2
(pF)
R1
(ohm)
(ohm) (pF)
(ohm) (pF)
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
270 330,000 220
270 100,000 270
270 100,000 390
270 100,000 510
270 100,000 620
270 100,000 820
270 330,000 300
270 100,000 390
270 100,000 560
270 100,000 750
270 100,000 1,000 270
270 100,000 1,200 270
270 100,000
270 100,000
270 100,000
390
560
750
1,000
1,200
2,200
2,200
750
560
560
560
680
330
680
270
560
100,000
100,000
100,000
6,800
3,300
6,800
510
680
910
270
10,000
5,600
1,200
1,200
2,200
2,200
910
1,100
1,200
1,200
1,200
1,500
2,200
2,200
2,200
2,700
910
1,100
1,200
1,200
1,200
1,500
2,200
2,200
2,200
2,700
910
1,100
1,200
1,200
1,200
1,500
2,200
2,200
2,200
2,700
12,000
5,600
270 100,000
270 100,000 1,000 270 100,000 1,500 270
2,700
270 100,000 330
270 100,000 390
270 100,000 510
270 100,000 560
270 100,000 620
270 100,000 750
270 100,000 820
270 100,000 910
270 100,000 510
270 100,000 560
270 100,000 750
270 100,000 820
270 100,000 1,000 270
270 100,000 1,100 270
270 100,000 1,200 270
270 100,000 1,300 270
100,000
100,000
6,800
4,700
3,300
3,300
6,800
3,900
2,700
270 100,000 866(1%) 560
270
270
10,000
12,000
5,600
1,000
1,200
1,200
1,200
2,200
2,200
2,200
2,200
750
680
470
330
330
680
390
270
270
560
3,900
12,000
10,000
5,600
270 100,000 1,000 270 100,000 1,500 270
270 100,000 1,200 270 100,000 1,600 270
19
20
3,300
270 100,000
270 100,000 866 (1%) 560
2,700
270 100,000 330
270 100,000 390
270 100,000 510
270 100,000 560
270 100,000 620
270 100,000 750
270 100,000 820
270 100,000 910
270 100,000 560
270 100,000 620
270 100,000 750
270 100,000 820
270 100,000 1,000 270
270 100,000 1,100 270
270 100,000 1,200 270
270 100,000 1,300 270
100,000
100,000
6,800
4,700
3,300
3,300
6,800
3,900
2,700
21-22
23-24
25-26
27-28
29-30
31-32
33-34
35-36
37-38
39-42
43-46
47-50
51-54
55-58
59-62
63-66
67-70
71-74
75-78
270
270
10,000
12,000
6,800
1,000
1,200
1,200
1,200
2,200
2,200
2,200
2,200
750
680
470
330
330
680
390
270
270
560
3,900
12,000
10,000
5,600
270 100,000 1,000 270 100,000 1,500 270
270 100,000 1,200 270 100,000 1,600 270
3,300
270 100,000
270 100,000 866 (1%) 560
2,700
270 100,000 330
270 100,000 390
270 100,000 510
270 100,000 560
270 100,000 620
270 100,000 750
270 100,000 820
270 100,000 910
270 100,000 560
270 100,000 620
270 100,000 750
270 100,000 820
270 100,000 1,000 270
270 100,000 1,100 270
270 100,000 1,200 270
270 100,000 1,300 270
100,000
100,000
6,800
4,700
3,300
3,300
6,800
3,900
2,700
270
270
10,000
12,000
6,800
3,900
12,000
8,200
5,600
3,300
1,000
1,200
1,200
1,200
2,200
2,200
2,200
2,200
680
470
330
330
680
390
270
270
270 100,000 1,000 270 100,000 1,600 270
270 100,000 1,200 270 100,000 1,800 270
2,700
Note: 1. The BW value is representative of typical conditions.
Rev. 2 | Page 3 of 8 | www.onsemi.com
P2781/82/84
Spread Spectrum Selection
The P278xA performs Zero Cycle Slip when set at low percentage spreading. This allows no 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: the center frequency is the frequency of the external reference input on CLKIN, Pin 1.)
The P2781A is designed for PC peripheral, networking, notebook PC, and LCD monitor applications. It is optimized for
operation between 3 to 78MHz range. In the following application schematic example, the P2781A spread percentage
selection is determined by the external LF value specified in the Loop Filter Selection Table. The Input Frequency Selection
Table specifies the input frequency range. The external LF allows the user to fine tune the spread percentage to optimize the
EMI reduction benefits of the spread spectrum.
+3.3V
16 MHz
XIN/CLKIN VDD
1
2
3
4
8
7
6
5
0.1µF
2.2 K
XOUT
FS0
FS1
Modulated 16MHz Clock
To target Chip
ModOUT
LF
VSS
P278xA
R1
C1
0 Ohm
C2
Note: Both logic input pins FS1 and FS0 have to be connected to either VDD or VSS. Do not leave them floating.
Rev. 2 | Page 4 of 8 | www.onsemi.com
P2781/82/84
Absolute Maximum Ratings
Symbol
Parameter
Rating
Unit
V
VDD, VIN
TSTG
Ts
Voltage on any pin with respect to Ground
Storage temperature
-0.5 to +4.6
-65 to +125
°C
Max. Soldering Temperature (10 sec)
Junction Temperature
260
150
2
°C
TJ
°C
TDV
Static Discharge Voltage (As per JEDEC STD22- A114-B)
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.
Operating Conditions
Parameter
Description
Min
3.0
Max
3.6
+85
15
Unit
V
VDD
TA
Supply Voltage
Operating Temperature (Ambient Temperature)
Load Capacitance
-40
°C
CL
pF
pF
CIN
Input Capacitance
7
DC Electrical Characteristics
(Test condition: All parameters are measured at room temperature (+25°C) unless otherwise stated.)
Symbol
VIL
Parameter
Min
VSS – 0.3
2.0
Typ
Max
Unit
V
Input low voltage
0.8
VIH
Input high voltage
Input low current
VDD +0.3
V
IIL
60
60
µA
µA
(internal input pull-up resistor on FS0 and FS1)
Input high current
IIH
(internal input pull-up resistor on FS0 and FS1)
IXOL
IXOH
XOUT output low current
XOUT output high current
10
10
mA
mA
VOL
VOH
Output low voltage (VDD = 3.3V, IOL = 20mA)
0.4
V
Output high voltage (VDD = 3.3V, IOH = 20mA)
Static supply current
2.5
V
IDD
ICC
3
mA
Typical dynamic supply current
(25pF scope probe loading)
5.2 at 3MHz
3.0
21.2 at 82MHz mA
3.6
VDD
Operating voltage
3.3
V
Rev. 2 | Page 5 of 8 | www.onsemi.com
P2781/82/84
AC Electrical Characteristics
Symbol
Parameter
Min
3
Typ
Max
78
Unit
fIN
Input frequency: P278xA
P2781A
P2782A
P2784A
3
78
MHz
fOUT
Output frequency:
6
156
312
12
Output rise time (measured at 0.8V to 2.0V,
25pF scope probe loading)
tLH
tHL
tJC
tD
P278xA
P278xA
P2781A
P2781A
1
1
nS
nS
pS
%
Output fall time (measured at 2.0V to 0.8V, 25
pF scope probe loading)
Jitter (cycle-to-cycle, ±6sigma, 1000 sweeps,
±0.5% spread, I/O frequency = 16MHz)
±250
Output duty cycle deviation (error from 50%
duty cycle, 25pF scope probe loading)
±1 @ 3MHz
-20
±2 @ 82MHz
+20
Frequency deviation tolerance from BW%
stated in the Loop Filter Selection Table
∆F
P278xA
0
%
Rev. 2 | Page 6 of 8 | www.onsemi.com
P2781/82/84
Package Information
8-Pin SOIC Package
H
E
D
A2
A
C
θ
e
A1
L
B
Dimensions
Symbol
Inches
Millimeters
Min
Max
0.010
0.069
0.059
0.020
0.010
Min
0.10
1.35
1.25
0.31
0.18
Max
0.25
1.75
1.50
0.51
0.25
A1
A
0.004
0.053
0.049
0.012
0.007
A2
B
C
D
E
0.193 BSC
0.154 BSC
0.050 BSC
0.236 BSC
4.90 BSC
3.91 BSC
1.27 BSC
6.00 BSC
e
H
L
0.016
0°
0.050
8°
0.41
0°
1.27
8°
θ
Note: Controlling dimensions are millimeters.
SOIC - 0.074 grams unit weight.
Rev. 2 | Page 7 of 8 | www.onsemi.com
P2781/82/84
Ordering Codes
Ordering #
Top Marking
ABG
Package Type
8 PIN SOIC, TUBE, Pb Free
Temperature
0°C to + 70°C
0°C to +70°C
P2781AF-08ST
P2781AF-08SR
I2781AF-08ST
I2781AG-08SR
P2782AF-08SR
P2784AF-08SR
ABG
8 PIN SOIC, TAPE AND REEL,Pb Free
8 PIN SOIC, TUBE, Pb Free
ABH
-40°C to +85°C
-40°C to +85°C
ABJ
8 PIN SOIC, TAPE AND REEL, Green
8 PIN SOIC, TAPE AND REEL,Pb Free
8 PIN SOIC, TAPE AND REEL,Pb Free
ABK
0°C to +70°C
0°C to +70°C
ABO
A “microdot” placed at the end of last row of marking or just below the last row toward the center of package indicates Pb-free.
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without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular
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including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or
specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be
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