View ASM3P2870A_316725.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

January 2005 rev 1.4
Low Power Peak EMI Reducing Solution
Features
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 4mA. Low power CMOS design. Input frequency range: 13MHz to 30MHz for 2.5V. : 13MHz to 30MHz for 3.3V. Generates a 1X low EMI spread spectrum clock of the input frequency. Frequency deviation: 0.75% ( Typ ) @ 22 MHz Input Frequency. Available in 6-pin TSOT-23, 8-pin SOIC and 8-pin TSSOP packages.
ASM3P2870A
The ASM3P2870A uses the most efficient and optimized modulation profile approved by the FCC and is implemented by using a proprietary all digital method. The ASM3P2870A 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 ASM3P2870A is targeted towards all portable devices with very low power requirements like MP3 players and digital still cameras.
Product Description
The ASM3P2870A is a versatile spread spectrum frequency modulator designed specifically for a wide range of clock frequencies. The ASM3P2870A reduces electromagnetic interference (EMI) at the clock source, allowing system wide reduction of EMI of all clock dependent signals. The ASM3P2870A 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 200 pS (Max) 45/55% (worst case) FIN/640 0.75% ( Typ ) @ 22 MHz
Block Diagram
VDD
XIN Crystal Oscillator Frequency Divider Feedback Divider REFOUT
Modulation
PLL
XOUT
Phase Detector
Loop Filter
VCO
Output Divider
ModOUT
VSS
Alliance Semiconductor 2575, Augustine Drive * Santa Clara, CA * Tel: 408.855.4900 * Fax: 408.855.4999 * www.alsc.com
Notice: The information in this document is subject to change without notice.
January 2005 rev 1.4
Pin Configuration (6-pin TSOT- 23 Package)
ASM3P2870A
REFOUT
1
6
VSS ModOUT VDD
XOUT 2 XIN / CLKIN 3
ASM3P2870A
5 4
Pin#
1 2 3 4 5 6
Pin Name
REFOUT XOUT XIN / CLKIN VDD ModOUT VSS
Type
O O I P O P
Description
Buffered output of the input frequency 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.
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
2 of 11
January 2005 rev 1.4
Pin Configuration (8-pin SOIC and TSSOP Package)
ASM3P2870A
XIN / CLKIN XOUT REFOUT NC
1 2 3 4
8 7 6 5
VDD NC ModOUT VSS
ASM3P2870A
Pin Description Pin#
1 2 3 4 5 6 7 8
Pin Name
XIN/CLKIN XOUT REFOUT NC VSS ModOUT NC VDD
Type
I O O - 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. Buffered output of the input frequency No connect. Ground connection. Spread spectrum clock output. No connect. Power supply for the entire chip.
Modulation Profile
Specifications
Description Frequency Range For 2.5V Supply For 3.3V Supply Specification 13MHz < CLKIN < 30MHz FIN/640 +0.75%(Typ) @22MHz
Modulation Equation Frequency Deviation
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
3 of 11
January 2005 rev 1.4
Absolute Maximum Ratings
Symbol VDD, VIN TSTG TA Ts TJ TDV Storage temperature Operating temperature Max. Soldering Temperature (10 sec) Junction Temperature Static Discharge Voltage (As per MIL-STD-883, Method 3015) Parameter Voltage on any pin with respect to Ground
ASM3P2870A
Rating 0.5 to +7.0 -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 for 2.5V Supply
(Test condition: All parameters are measured at room temperature (+25C) unless otherwise stated)
Symbol VIL VIH IIL IIH IXOL IXOH VOL VOH IDD ICC VDD tON ZOUT Input low voltage Input high voltage Input low current Input high current
Parameter
Min GND - 0.3 2.0 - - - - - 1.8 - - 2.375 - -
Typ - - - - 3 3 - - 1.0 3.0 2.5 - 50
Max 0.8 VDD + 0.3 -35 35 - - 0.6 - - - 2.625 5 -
Unit V V NA NA mA mA V V mA mA V mS Q
XOUT output low current (@0.5V, VDD=2.5V) XOUT output high current (@1.8V, VDD=2.5V) Output low voltage (VDD = 2.5 V, IOL = 8 mA) Output high voltage (VDD = 2.5 V, IOH = 8 mA) Static supply current* Dynamic supply current (2.5V, 22MHz and no load) Operating voltage Power-up time (first locked cycle after power-up) Output impedance
* XIN /CLKIN pin is pulled low
AC Electrical Characteristics for 2.5V Supply
Symbol CLKIN ModOUT fd tLH* tHL* tJC tD Input frequency Output frequency Frequency Deviation Input Frequency = 13MHz Input Frequency = 30MHz Parameter Min 13 13 - - 0.7 0.4 - 45 Typ - - - - 1.4 0.8 - 50 Max 30 30 1.20 0.47 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
* tLH and tHL 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 11
January 2005 rev 1.4
DC Electrical Characteristics for 3.3V Supply
(Test condition: All parameters are measured at room temperature (+ 25C) unless otherwise stated)
ASM3P2870A
Symbol VIL VIH IIL IIH IXOL IXOH VOL VOH IDD ICC VDD tON ZOUT Input low voltage Input high voltage Input low current Input high current
Parameter
Min GND - 0.3 2.0 - - - - - 2.5 - - 2.7 - -
Typ - - - - 3 3 - - 1.2 4.0 3.3 - 45
Max 0.8 VDD + 0.3 -35 35 - - 0.4 - - - 3.6 5 -
Unit V V NA NA mA mA V V mA mA V mS Q
XOUT output low current (@0.4V, VDD=3.3V) XOUT output high current (@2.5V, VDD=3.3V) Output low voltage (VDD = 3.3 V, IOL = 8 mA) Output high voltage (VDD = 3.3 V, IOH = 8 mA) Static supply current* Dynamic supply current (3.3V, 22MHz and no load) Operating voltage Power-up time (first locked cycle after power-up)** Output impedance
* XIN /CLKIN pin is pulled low.
AC Electrical Characteristics for 3.3V Supply
Symbol CLKIN ModOUT fd tLH* tHL * tJC tD Input frequency Output frequency Frequency Deviation Input Frequency = 13MHz Input Frequency = 30MHz Parameter Min 13 13 - - 0.4 0.3 - 45 Typ - - - - 1.2 0.8 - 50 Max 30 30 1.20 0.47 1.5 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
*tLH and tHL 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.
5 of 11
January 2005 rev 1.4
Typical Crystal Oscillator Circuit
ASM3P2870A
Crystal
R1 = 510Q
C1 = 27 pF
C2 = 27 pF
Typical Crystal Specifications
Fundamental AT cut parallel resonant crystal Nominal frequency Frequency tolerance Operating temperature range Storage temperature Load capacitance Shunt capacitance ESR 14.31818 MHz 50 ppm or better at 25C -25C to +85C -40C to +85C 18pF 7pF maximum 25
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
6 of 11
January 2005 rev 1.4
Package Information 6-pin TSOT-23 Package
ASM3P2870A
Dimensions Symbol Min A A1 A2 b H D B e C L S 0.0118 0 0.00 0.033 0.012 0.005 BSC 0.114 BSC 0.06 BSC 0.0374 BSC 0.11 BSC 0.02 4 0.30 0 Inches Max 0.04 0.004 0.036 0.02 0.00 0.84 0.30 0.127 BSC 2.90 BSC 1.60 BSC 0.950 BSC 2.80 BSC 0.50 4 Min Millimeters Max 1.00 0.10 0.90 0.50
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
7 of 11
January 2005 rev 1.4
8-Pin SOIC Package
ASM3P2870A
E
H
D
A2
A C
e B
A 1
D
L
Dimensions Symbol Min A1 A A2 B C D E e H L S 0.004 0.053 0.049 0.012 0.007 Inches Max 0.010 0.069 0.059 0.020 0.010 Millimeters Min 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 Max 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
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
8 of 11
January 2005 rev 1.4
8-Pin TSSOP Package
ASM3P2870A
H
E D A2 A C e B A1 L
Dimensions Symbol Min A A1 A2 B c D E e H L S 0.020 0 0.002 0.033 0.008 0.004 0.114 0.169 0.026 BSC 0.252 BSC 0.028 8 0.50 0 Inches Max 0.043 0.006 0.037 0.012 0.008 0.122 0.177 0.05 0.85 0.19 0.09 2.90 4.30 0.65 BSC 6.40 BSC 0.70 8 Min Millimeters Max 1.10 0.15 0.95 0.30 0.20 3.10 4.50
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
9 of 11
January 2005 rev 1.4
Ordering Information
Part Number ASM3P2870AF-06OR ASM3P2870AF-08TT ASM3P2870AF-08TR ASM3P2870AF-08ST ASM3P2870AF-08SR ASM3P2870A-06OR ASM3P2870A-08TT ASM3P2870A-08TR ASM3P2870A-08ST ASM3P2870A-08SR Marking C4LL 3P2870AFT 3P2870AFT 3P2870AFS 3P2870AFS C1LL 3P2870AT 3P2870AT 3P2970AS 3P2870AS Package Type
ASM3P2870A
Temperature Commercial Commercial Commercial Commercial Commercial Commercial Commercial Commercial Commercial Commercial
6-Pin TSOT-23, TAPE & REEL, Pb Free 8-Pin TSSOP, TUBE, Pb Free 8-Pin TSSOP, TAPE & REEL, Pb Free 8-Pin SOIC, TUBE, Pb Free 8-Pin SOIC, TAPE & REEL, Pb Free 6-Pin TSOT-23, TAPE & REEL 8-Pin TSSOP, TUBE 8-Pin TSSOP, TAPE & REEL 8-Pin SOIC, TUBE 8-Pin SOIC, TAPE & REEL
Device Ordering Information
ASM3P2870AF-08TR
OR - TSOT23-6,T/R TT - TSSOP, TUBE TR - TSSOP, T/R VT - TVSOP, TUBE VR - TVSOP, T/R ST - SOIC, TUBE SR - SOIC, T/R QR - QFN, T/R QT - QFN, TUBE BT - BGA, TUBE BR - BGA, T/R
PIN COUNT LEAD FREE PART PART NUMBER X = Automotive (-40C to +125C) I = Industrial (-40C to +85C) P or n/c = Commercial (0C to +70C)
1 - reserved 2 - Non PLL based 3 - EMI Reduction 4 - DDR support products 5 - STD Zero Delay Buffer
6 - power management 7 - power management 8 - power management 9 - Hi performance 0 - reserved
Alliance Semiconductor Mixed Signal Product
Licensed under U.S Patent Nos 5,488,627 and 5,631,921
Low Power Peak EMI Reducing Solution
Notice: The information in this document is subject to change without notice.
10 of 11

▲Up To Search▲

Price & Availability of ASM3P2870A

	To Download ASM3P2870A Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .