The ASM3P2780A uses the most efficient and optimized
modulation profile approved by the FCC and is
implemented by using a proprietary all digital method.
The ASM3P2780A 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’.
Generates an 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: 30MHz to 50MHz for 2.5V.
: 30MHz to 50MHz for 3.3V.
Generates a 1X low EMI spread spectrum clock of
the input frequency.
Frequency deviation: ±0.75% (Typ) @46MHz
Input Frequency.
Available in 6 pin TSOT-23, 8 pin SOIC and 8 pin
TSSOP Packages.
Applications
The ASM3P2780A is targeted towards all portable
devices with very low power requirements like MP3
players and digital still cameras.
Product Description
The ASM3P2780A is a versatile spread spectrum
frequency modulator designed specifically for a wide
range of clock frequencies. The ASM3P2780A reduces
electromagnetic interference (EMI) at the clock source,
allowing system wide reduction of EMI of
all clock
dependent signals. The ASM3P2780A 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
V
DD
= 3.3V / 2.5V
200pS (Max)
45/55%
F
IN
/1280
±0.75 (Typ) @ 46MHz
Block Diagram
V
DD
PD
Modulation
XIN/CLKIN
XOUT
Crystal
Oscillator
Frequency
Divider
Feedback
Divider
Phase
Detector
Loop
Filter
PLL
VCO
Output
Divider
ModOUT
V
SS
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 1.6
Pin Configuration (6-pin TSOT- 23 Package)
PD 1
XOUT 2
XIN / CLKIN 3
6 V
SS
ASM3P2780A
ASM3P2780A
5 ModOUT
4 V
DD
Pin Description
Pin#
1
2
3
4
5
6
Pin Name
PD
XOUT
XIN / CLKIN
V
DD
ModOUT
V
SS
Type
I
O
I
P
O
P
Description
Power-down control pin. Pull low to enable power-down mode. Connect to V
DD
if not
used.
Crystal connection. If using an external reference, this pin must be left unconnected.
Crystal connection or external reference frequency input. This pin has dual functions. It
can be connected either to an external crystal or an external reference clock.
Power supply for the entire chip.
Spread spectrum clock output.
Ground connection.
Pin Configuration (8-pin SOIC and TSSOP Packages)
XIN / CLKIN
1
XOUT
2
PD
NC
3
4
8
7
6
5
V
DD
NC
ModOUT
V
SS
ASM3P2780A
Pin Description
Pin#
1
2
3
4
5
6
7
8
Pin Name
XIN/CLKIN
XOUT
PD
NC
V
SS
ModOUT
NC
V
DD
Type
I
O
I
-
P
O
-
P
Description
Crystal connection or external reference frequency 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.
Power-down control pin. Pull low to enable power-down mode. Connect to VDD if not
used.
No connect.
Ground connection.
Spread spectrum clock output.
No connect.
Power supply for the entire chip.
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
2 of 12
November
2006
rev 1.6
Modulation Profile
ASM3P2780A
Specifications
Description
Frequency Range
Modulation Equation
Frequency Deviation
For 2.5V Supply
For 3.3V Supply
Specification
30MHz < CLKIN < 50MHz
F
IN
/1280
±0.75% (Typ) @ 46MHz
Absolute Maximum Ratings
Symbol
V
DD
, 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)
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
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
3 of 12
November
2006
rev 1.6
DC Electrical Characteristics for 2.5V Supply
(Test condition: All parameters are measured at room temperature (+25°C) unless otherwise stated)
ASM3P2780A
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
Input high current
Parameter
Min
V
SS
- 0.3
2.0
-
-
-
-
-
1.8
-
-
2.375
-
-
Typ
-
-
-
-
3
3
-
-
-
4.0
2.5
-
50
Max
0.8
V
DD
+ 0.3
-35
35
-
-
0.6
-
10
-
2.625
5
-
Unit
V
V
µA
µA
mA
mA
V
V
uA
mA
V
mS
Ω
XOUT output low current (@0.6V, V
DD
=2.5V)
XOUT output high current (@1.8V, V
DD
=2.5V)
Output low voltage (V
DD
= 2.5 V, I
OL
= 8mA)
Output high voltage (V
DD
= 2.5 V, I
OH
= 8mA)
Static supply current*
Dynamic supply current (2.5V, 46MHz and no load)
Operating Voltage
Power-up time (first locked cycle after power-up)**
Output impedance
* XIN /CLKIN pin and PD pin are pulled low
** V
DD
and XIN/CLKIN input are stable, PD pin is made high from 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 = 30MHz
Input Frequency = 50MHz
Parameter
Min
30
30
-
-
0.7
0.4
-
45
Typ
-
-
± 1.10
± 0.65
1.3
0.8
-
50
Max
50
50
-
-
1.6
1.0
200
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.
4 of 12
November
2006
rev 1.6
DC Electrical Characteristics for 3.3V Supply
(Test condition: All parameters are measured at room temperature (+ 25°C) unless otherwise stated)
ASM3P2780A
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
Input high current
Parameter
Min
V
SS
- 0.3
2.0
-
-
-
-
-
2.5
-
-
2.7
-
-
Typ
-
-
-
-
3
3
-
-
-
5.0
3.3
-
45
Max
0.8
V
DD
+ 0.3
-35
35
-
-
0.4
-
10
-
3.6
5
-
Unit
V
V
µA
µA
mA
mA
V
V
uA
mA
V
mS
Ω
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
= 3.3 V, I
OL
= 8mA)
Output high voltage (V
DD
= 3.3 V, I
OH
= 8mA)
Static supply current*
Dynamic supply current (3.3V, 46MHz and no load)
Operating Voltage
Power-up time (first locked cycle after power-up)**
Output impedance
* XIN /CLKIN pin and PD pin are pulled low
** V
DD
and XIN/CLKIN input are stable, PD pin is made high from 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 = 30MHz
Input Frequency = 50MHz
Parameter
Min
30
30
-
-
0.5
0.3
-
45
Typ
-
-
±1.10
± 0.65
1.1
0.8
-
50
Max
50
50
-
-
1.4
1.1
200
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.
[i=s]This post was last edited by uniquey on 2016-12-12 15:49[/i] [align=left]At the beginning of the article, let's first learn about the basic information of LSM6DSM. [/align][align=left]Although so...
[i=s]This post was last edited by paulhyde on 2014-9-15 03:05[/i] I've been learning about quadcopters recently. I read a document saying that commercial ESCs cannot respond quickly: Commercial ESCs o...
I am currently doing JAVA development (I am a computer science graduate) and I want to switch to hardware development. Can you please show me a learning path? Thank you....
Silicon Labs BG22-EK4108A is developed using Silicon Labs' own Simplicity Studio V5. This IDE is based on eclipse, but it is super smooth and easy to use. Whether it is SDK update or automatic board r...
Reprinted from: deyisupport [align=left][color=#000]Designers must meet many electromagnetic compatibility (EMC) requirements for automotive applications, and choosing the right switching frequency (f...
On August 24th, Jin Yuzhi, CEO of Huawei's Intelligent Automotive Solutions BU, announced the first automotive application of Huawei Qiankun's unique Limera technology. This technology eliminates t...[Details]
Abstract:
With the increasing complexity of smart vehicle electrical and electronic architectures, the full lifecycle management of vehicle electronic control components faces multiple challe...[Details]
A line scan lens is an industrial lens used with line scan cameras. Its imaging principle is to capture the image of the workpiece using a linear sensor and then perform digital signal processing t...[Details]
In recent years, with the application of the IEC61850 standard and the development and deployment of optoelectronic transformers, the concept of digital substations has been put into practical use ...[Details]
Capable of providing precise and efficient thermal management for artificial intelligence computing power, intelligent sensing and autonomous driving systems
Shenzhen, ...[Details]
1 Introduction
In the mid-1960s, American scientist Maas conducted extensive experimental research on the charging process of open-cell batteries and proposed an acceptable charging curve for ...[Details]
Definition of interactive projection system:
Interactive projection systems, also known as multimedia interactive projection, are available in floor, wall, and tabletop interactive projection....[Details]
Electric vehicles are becoming increasingly popular, with increasingly longer ranges. There are two ways to charge electric vehicles: slow charging and fast charging. Which is the most suitable? Sl...[Details]
UPS stands for Uninterruptible Power Supply, which includes energy storage devices. It is mainly used to provide uninterruptible power supply for devices that require high power stability.
...[Details]
Through AI connection technology supported by Qualcomm X85 5G modem and RF and Qualcomm FastConnect 7900 mobile connection system, seamless switching can be achieved between cellular net...[Details]
Recently, Joyson Electronics has made positive progress in the core technology research and development of the robot's "brain and brain" and key components, and launched the industry's first integr...[Details]
Consumer demand for premium listening experiences has driven rapid evolution in the wireless headphone market in recent years. Hybrid designs, which utilize two drivers per earbud to enhance sound ...[Details]
With the continuous development of ultrasonic technology, ultrasound has been widely used in fields such as inspection, cleaning, welding, and medical treatment, and has even found its way into tex...[Details]
With the development of vehicle technology, there are more types of cars. Cars are divided into hybrid, pure electric vehicles, and fuel vehicles. For hybrid cars, they are divided into plug-in hyb...[Details]
The power transmission system between a car's engine and drive wheels is called its drivetrain. It ensures the necessary traction and speed under various driving conditions, and coordinates these t...[Details]
MEMS sensors
京公网安备 11010802033920号
EEWORLD
