Generates a 1X low EMI optimized clock signal at the
output.
Integrated loop filter components.
Operates with a 3.3 / 2.5V Supply.
Operating current less than 5mA.
Low power CMOS design.
Input frequency range
60MHz to 120MHz for 2.5V
60MHz to 120MHz for 3.3V
•
Frequency deviation:
±0.75%
(Typ) @85MHz Output
frequency.
•
Available in 6-pin TSOT-23 Package.
ASM3P2590A
The ASM3P2590A uses the most efficient and optimized
modulation profile approved by the FCC and is
implemented by using a proprietary all digital method.
The ASM3P2590A 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 ASM3P2590A is targeted towards all portable
devices with very low power requirements like MP3
players,MFP, LCD Panel Module and digital still cameras.
Product Description
The ASM3P2590A is a versatile spread spectrum
frequency modulator designed specifically for a wide
range of clock frequencies. The ASM3P2590A reduces
electromagnetic interference (EMI) at the clock source,
allowing system wide reduction of EMI of
all clock
dependent signals. The ASM3P2590A allows significant
system cost savings by reducing the number of circuit
board layers ferrite beads, shielding that are traditionally
required to pass EMI regulations.
Key Specifications
Description
Supply voltages
Cycle-to-Cycle Jitter
Output Duty Cycle
Modulation Rate Equation
Frequency Deviation
Specification
VDD = 3.3V / 2.5V
360pS (Typ)
45/55%
F
IN
/2560
±0.75%
(Typ) @85MHz
Output
Block Diagram
VDD
SSON
Modulation
CLKIN
Frequency
Divider
Feedback
Divider
PLL
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.
September 2006
rev 0.4
Pin Configuration (6-pin TSOT- 23 Package)
ASM3P2590A
SSON
NC
1
2
6
VSS
ModOUT
VDD
ASM3P2590A
5
4
CLKIN
3
Pin Description
Pin#
1
2
3
4
5
6
Pin Name
SSON
NC
CLKIN
VDD
ModOUT
VSS
Type
I
-
I
P
O
P
Description
When SSON is HIGH, the spread spectrum is enabled and when LOW, it turns off the
spread spectrum. Connect the pin to ground When Spread Spectrum feature is not
required.
No Connect
Clock Input
Power supply for the entire chip.
Spread spectrum clock output.
Ground connection.
Modulation Profile
Specifications
Description
Frequency Range
Modulation Equation
Frequency Deviation
For 2.5V Supply
For 3.3V Supply
Specification
60MHz < CLKIN < 120MHz
60MHz < CLKIN < 120MHz
F
IN
/2560
±0.75%
(Typ) @ 85MHz Output
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
2 of 7
September 2006
rev 0.4
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)
ASM3P2590A
Parameter
Voltage on any pin with respect to Ground
Rating
-0.5 to +4.6
-65 to +125
-40 to +85
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 for 2.5V Supply
Symbol
V
IL
V
IH
I
IL
I
IH
V
OL
V
OH
IDD
I
CC
VDD
t
ON
Z
OUT
Input low voltage
Input high voltage
Input low current
Input high current
Output low voltage (VDD = 2.5V, I
OL
= 8 mA)
Output high voltage (VDD = 2.5V, I
OH
= 8 mA)
Static supply current*
Dynamic supply current (2.5V, 85MHz and no load)
Operating voltage
Power-up time (first locked cycle after power-up)
Output impedance
Parameter
Min
VSS - 0.3
2.0
–
–
–
1.8
–
–
2.375
–
–
Typ
–
–
–
–
–
–
1.8
4.0
2.5
–
50
Max
0.8
VDD + 0.3
-35
35
0.6
–
–
–
2.625
5
–
Unit
V
V
µA
µA
V
V
mA
mA
V
mS
Ω
* CLKIN pin is pulled low
AC Electrical Characteristics for 2.5V Supply
Symbol
CLKIN
ModOUT
f
d
t
LH
*
t
HL
*
t
JC
t
D
Input frequency
Output frequency
Frequency Deviation
Input Frequency = 60MHz
Input Frequency = 120MHz
Parameter
Min
60
60
–
–
0.7
0.4
–
45
Typ
–
–
±0.85
±0.60
1.8
0.9
360
50
Max
120
120
–
–
2.6
1.1
–
55
Unit
MHz
MHz
%
nS
nS
pS
%
Output rise time (measured from 0.7V to 1.7V)
Output fall time (measured from 1.7V to 0.7V)
Jitter (Cycle to cycle)
Output duty cycle
* t
LH
and t
HL
are measured into a capacitive load of 15pF
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
3 of 7
September 2006
rev 0.4
DC Electrical Characteristics for 3.3V Supply
Symbol
V
IL
V
IH
I
IL
I
IH
V
OL
V
OH
IDD
I
CC
VDD
t
ON
Z
OUT
Input low voltage
Input high voltage
Input low current
Input high current
Output low voltage (VDD = 3.3V, I
OL
= 8 mA)
Output high voltage (VDD = 3.3V, I
OH
= 8 mA)
Static supply current*
Dynamic supply current (3.3V, 85MHz and no load)
Operating voltage
Power-up time (first locked cycle after power-up)
Output impedance
ASM3P2590A
Parameter
Min
VSS - 0.3
2.0
–
–
–
2.5
–
–
3.0
–
–
Typ
–
–
–
–
–
–
2.2
4.5
3.3
–
45
Max
0.8
VDD + 0.3
-35
35
0.4
–
–
–
3.6
5
–
Unit
V
V
µA
µA
V
V
mA
mA
V
mS
Ω
* CLKIN pin is pulled low
AC Electrical Characteristics for 3.3V Supply
Symbol
CLKIN
ModOUT
f
d
t
LH
*
t
HL
*
t
JC
t
D
Input frequency
Output frequency
Frequency Deviation
Input Frequency = 60MHz
Input Frequency = 120MHz
Parameter
Min
60
60
–
–
0.5
0.3
–
45
Typ
–
–
±0.85
±0.60
1.2
0.8
360
50
Max
120
120
–
–
1.8
1.1
–
55
Unit
MHz
MHz
%
nS
nS
pS
%
Output rise time (measured from 0.8 to 2.0V)
Output fall time (measured at 2.0V to 0.8V)
Jitter (cycle to cycle)
Output duty cycle
*t
LH
and t
HL
are measured into a capacitive load of 15pF
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
4 of 7
September 2006
rev 0.4
Package Information
6-pin TSOT-23 Package
ASM3P2590A
Dimensions
Symbol
Min
A
A1
A2
b
H
D
B
e
C
L
θ
0.00
0.033
0.012
Inches
Max
0.04
0.004
0.036
0.02
Millimeters
Min
Max
1.00
0.00
0.84
0.30
0.127 BSC
2.90 BSC
1.60 BSC
0.950 BSC
2.80 BSC
0.30
0°
0.50
4°
0.10
0.90
0.50
0.005 BSC
0.114 BSC
0.06 BSC
0.0374 BSC
0.11 BSC
0.0118
0°
0.02
4°
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
