ASM3P2812 D

ASM3P2811A/B and ASM3P2812A/B and ASM3P2814A/B
Low Power EMI Reduction IC
Features
• FCC approved method of EMI attenuation
• Provides up to 15dB EMI reduction
• Generates a 1x, 2x and 4x low EMI spread spectrum
clock of the input frequency
o 1x: ASM3P2811A/B
o 2x: ASM3P2812A/B
o 4x: ASM3P2814A/B
• Optimized for input frequency range from 10MHz to
40MHz
• Internal loop filter minimizes external components
and board space
• Selectable spread options:
o Down Spread and Center Spread
• 8 frequency deviation selections:
o ±0.625% to -3.5%
• Low inherent Cycle-to-Cycle Jitter
• 3.3V Operating Voltage
• CMOS/TTL compatible inputs and outputs.
• Pin-out compatible with Cypress CY25811, CY25812
and CY25814
• Available in 8-pin SOIC and TSSOP Packages
combinations of spread options and percentage
deviations. Refer to Frequency Deviation and Spread
Selection Table. These combinations include Down and
Center Spread, and percentage deviation range from
±0.625% to -3.5%.
The ASM3P28XX reduces electromagnetic interference
(EMI) at the clock source, allowing system wide reduction
of EMI of downstream clock and data dependent signals.
The ASM3P28XX allows significant system cost savings
by reducing the number of circuit board layers, ferrite
beads, shielding, and other passive components that are
traditionally required to pass EMI regulations.
The ASM3P28XX 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’.
The ASM3P28XX uses the most efficient and optimized
modulation profile approved by the FCC and is
implemented in a proprietary all-digital method.
Product Description
The ASM3P28XX devices are versatile spread spectrum
frequency modulators designed specifically for a wide
range of input clock frequencies from 10MHz to 40MHz.
Refer to Input/Output Frequency Range Selection Table.
The ASM3P28XX can generate an EMI reduced clock
from crystal, ceramic resonator, or system clock. The
ASM3P28XX-A and the ASM3P28XX-B offer various
©2010 SCILLC. All rights reserved.
OCTOBER 2010 – Rev. 2.1
Applications
The ASM3P28XX is targeted towards EMI management
for memory and LVDS interfaces in mobile graphic
chipsets and high-speed digital applications such as PC
peripheral devices, consumer electronics, and embedded
controller systems.
Publication Order Number:
ASM3P2811/D
ASM3P2811A/B and ASM3P2812A/B and ASM3P2814A/B
Block Diagram
VDD
D_C SRS FRS
PLL
Modulation
XIN / CLKIN
Crystal
Oscillator
Frequency
Divider
XOUT
Feedback
Divide
r
Phase
Detector
Loop
Filter
VCO
Output
Divider
ModOUT
VSS
Pin Configuration
XIN / CLKIN 1
VSS 2
D_C 3
ASM3P2811A/B
ASM3P2812A/B
ASM3P2814A/B
SRS 4
8
XOUT
7
VDD
6
FRS
5
ModOUT
Pin Description
Pin#
Pin Name
Type
Description
1
XIN / CLKIN
I
Crystal connection or external Clock input.
2
VSS
P
Ground to entire chip.
3
D_C
I
4
SRS
I
5
ModOUT
O
Spread spectrum clock output.
6
FRS
I
Frequency range select. Digital logic input used to select Input frequency range
(Refer to Input/Output Frequency Range Selection Table).
This pin has an internal pull-up resistor.
7
VDD
P
Power supply for the entire chip.
8
XOUT
O
Crystal connection. If using an external reference, this pin must be left
unconnected.
Digital logic input used to select Down (LOW) or Center (HIGH) spread options.
(Refer to Frequency Deviation and Spread Selection Table).
This pin has an internal pull-up resistor.
Spread range select. Digital logic input used to select frequency deviation
(Refer to Frequency Deviation and Spread Selection Table).
This pin has an internal pull-up resistor.
.
Rev. 2 | Page 2 of 7 | www.onsemi.com
ASM3P2811A/B and ASM3P2812A/B and ASM3P2814A/B
Input/Output Frequency Range Selection Table
Part Number
FRS (pin 6)
ASM3P2811 (1x)
ASM3P2812 (2x)
ASM3P2814 (4x)
Modulation Rate
Input
(MHz)
Output
(MHz)
Input
(MHz)
Output
(MHz)
Input
(MHz)
Output
(MHz)
0
10-20
10-20
10-20
20-40
10-20
40-80
Input Frequency / 448
1
20-40
20-40
20-40
40-80
20-40
80-160
Input Frequency / 896
Output Frequency Deviation and Spread Selection Table
1
Frequency Deviation (%)
Part Number
ASM3P28XXA
ASM3P28XXB
D_C
(pin 3)
SRS
(pin 4)
FS=0
FS=1
10/20/40 (MHz)
20/40/80 (MHz)
20/40/80 (MHz)
40/80/160 (MHz)
0
0
-3
-2.5
-2.7
-2.6
0
1
-3.7
-3.4
-3.8
-3.6
1
0
±1.5
±1.2
±1.5
±1.3
1
1
±1.8
±1.6
±1.9
±1.8
0
0
-1.7
-1.0
-1.5
-1.4
0
1
-2.0
-1.5
-2.0
-1.9
1
0
±0.75
±0.6
±0.8
±0.7
1
1
±1.0
±0.75
±1.0
±0.9
Note: 1. Frequency Deviation given in the table is for the Output Frequency Range covering ASM3P2811x / 12x / 14x.
Absolute Maximum Ratings
Symbol
VDD, VIN
TSTG
Parameter
Rating
Unit
Voltage on any pin with respect to Ground
-0.5 to +4.6
V
Storage temperature
-65 to +125
°C
Ts
Max. Soldering Temperature (10 sec)
260
°C
TJ
Junction Temperature
150
°C
TDV
Static Discharge Voltage(As per JEDEC STD 22- A114-B)
2
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.
.
Rev. 2 | Page 3 of 7 | www.onsemi.com
ASM3P2811A/B and ASM3P2812A/B and ASM3P2814A/B
Operating Conditions
Symbol
Min
Max
Unit
Supply Voltage
3.0
3.6
V
TA
Operating temperature
-40
+85
°C
CL
Load Capacitance
10
pF
CIN
Input Capacitance
7
pF
Max
Unit
VSS – 0.3
0.8
V
2
VDD + 0.3
V
-50
µA
50
µA
3
mA
3
mA
0.4
V
VDD
Parameter
DC Electrical Characteristics
Symbol
Parameter
Min
VIL
Input low voltage
VIH
Input high voltage
Input low current
(Inputs D_C, SRS and FRS are pulled high internally)
IIL
IIH
Typ
Input high current
IXOL
IXOH
XOUT Output low current
(VXOL@ 0.4V, VDD = 3.3V)
XOUT Output high current
(VXOH@ 2.5V, VDD = 3.3V)
VOL
Output low voltage (VDD = 3.3V, IOL = 5mA)
VOH
Output high voltage (VDD = 3.3V, IOH = -5mA)
ICC
Dynamic supply current (Unloaded Output)
IDD
Static supply current , Standby mode
(CLKIN pulled to GND)
VDD
tON
ZOUT
Operating voltage
2.5
V
8
3.0
3.3
Power up time (first locked clock cycle after power up)
Clock out impedance
18
mA
4.5
mA
3.6
V
500
µS
76
Ω
AC Electrical Characteristics
Symbol
fIN
fOUT
1
tLH
tHL
1
Parameter
Min
Typ
Max
Unit
Input frequency for ASM3P2811/12/13/14 A/B
10
40
MHz
Output frequency for ASM3P2811A/B
10
40
MHz
Output frequency for ASM3P2812A/B
20
80
MHz
Output frequency for ASM3P2814A/B
40
160
MHz
Output rise time (measured at 0.8V to 2.0V)
0.5
0.9
1.2
nS
Output fall time (measured at 2.0V to 0.8V)
0.8
1.0
1.3
nS
tJC
Cycle-to-Cycle Jitter (Unloaded Output)
tD
Output duty cycle
±250
45
Note: 1. tLH and tHL are measured into a capacitive load of 10pF
.
Rev. 2 | Page 4 of 7 | www.onsemi.com
50
pS
55
%
ASM3P2811A/B and ASM3P2812A/B and ASM3P2814A/B
Package Information
8-Pin SOIC Package
H
E
D
A2
A
θ
C
D
e
A1
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
θ
0°
8°
0.41
1.27
0°
8°
Note: Controlling dimensions are millimeters.
SOIC: 0.074 grams unit weight.
.
Rev. 2 | Page 5 of 7 | www.onsemi.com
ASM3P2811A/B and ASM3P2812A/B and ASM3P2814A/B
8-lead TSSOP (4.40-MM Body)
H
E
D
A2
A
θ
e
C
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
θ
0°
8°
0.50
0.70
0°
8°
.
Rev. 2 | Page 6 of 7 | www.onsemi.com
ASM3P2811A/B and ASM3P2812A/B and ASM3P2814A/B
Ordering Code
Part Number
Marking
Package Type
Temperature
ASM3P2811AF-08SR
ACH
8-Pin SOIC, Tape & Reel, Pb free
0°C to 70°C
ASM3P2811BF-08SR
ACJ
8-Pin SOIC, Tape & Reel, Pb free
0°C to 70°C
ASM3P2812AF-08SR
ACL
8-Pin SOIC, Tape & Reel, Pb free
0°C to 70°C
ASM3P2812AF-08TR
ACL
8-Pin TSSOP, Tape & Reel, Pb free
0°C to 70°C
ASM3P2812BF-08SR
ACN
8-Pin SOIC, Tape & Reel, Pb free
0°C to 70°C
ASM3P2814AF-08SR
ACP
8-Pin SOIC, Tape & Reel, Pb free
0°C to 70°C
ASM3P2814BF-08TR
ACR
8-Pin TSSOP, Tape & Reel, Pb free
0°C to 70°C
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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