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SM8721AB 3-PLL Multi-Output Clock Generator
OVERVIEW
The SM8721AB is a clock generator IC with 3 built-in PLLs. It can simultaneously generate and output 3 clocks with different frequency derived from a single master clock. The generated output clock frequency can be switched using control pins and one clock can be turned ON/OFF (CLK2). The master clock can be selected from a low-cost 14.31818MHz or small 28.636363MHz crystal. The device is available in compact 20-pin QFN packages, making it ideal for portable digital still cameras and other applications which require multiple clocks.
FEATURES
I I I
PINOUT
(Top view)
VDD1 VDD1 VSS1 CLK2ON CLK1
15 14 13 12 11
I
I
I
I
3.0 to 3.6V supply voltage Crystal oscillator circuit built-in 14.318182/28.636363MHz master clock (internal PLL reference clock) Generated clocks * 14.318182/17.734450MHz (REF_CLK) * 71.877274/90.314686/96.016044 /114.54546MHz (CLK1) * 48.008022/96.016044MHz (CLK2) Low jitter output * 30ps typ. (1-sigma) * 180ps typ. (peak-to-peak) Output load * 15pF 20-pin QFN package (Pb free)
CLK2 VSS2 VDD2 REF_CLK TEST2
16 17 18 19 20 12345
10 9 8 7 6
FS1 FS2 FS3 XTAL_SEL TEST1
APPLICATIONS
I
PACKAGE DIMENSIONS
(Unit: mm) Weight: 0.037g
4.20 0.20
Digital still cameras
ORDERING INFORMATION
Device SM8721AB Package
4.20 0.20 4.00 0.10 4.00 0.10
15 16 11
10
20-pin QFN
20
1
5 0.50
VDD3 VDD3 VSS3 XTI XTO
6
0.60 0.10
+ 0.03 0.02 - 0.02
0.05
0.22 0.05
0.05 M
SEIKO NPC CORPORATION --1
1.00max
0.22
SM8721AB
BLOCK DIAGRAM
Reference Divider 1 XTI Oscillator XTO (PLL1)
Phase Detector 1
Charge Pump 1
LPF 1
VCO 1
CLK1
Loop Divider 1
CLK2ON
Reference Divider 2
Phase Detector 2
Charge Pump 2
LPF 2
VCO 2
CLK2
(PLL2) FS1 FS2 FS3 XTAL_SEL TEST1 TEST2 (PLL3) Control Logic
Loop Divider 2
Reference Divider 3
Phase Detector 3
Charge Pump 3
LPF 3
VCO 3
REF_CLK
Loop Divider 3
PIN DESCRIPTION
Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Name VDD3 VDD3 VSS3 XTI XTO TEST1 XTAL_SEL FS3 FS2 FS1 CLK1 CLK2ON VSS1 VDD1 VDD1 CLK2 VSS2 VDD2 REF_CLK TEST2 I/O - - - I O I I I I I O I - - - O - - O I Analog supply voltage 3 Analog supply voltage 3 Analog supply ground 3 Crystal oscillator element connection pin (14.318182/28.636363MHz) Crystal oscillator element connection pin Test pin 1. Built-in pull-down resistance (leave open circuit or connect to VSS) Crystal oscillator element selection pin. Built-in pull-up resistance (HIGH = 28.636MHz, LOW = 14.318MHz) CLK1, CLK2 output select 3. Built-in pull-up resistance CLK1, CLK2 output select 2. Built-in pull-up resistance REF_CLK output select 1. Built-in pull-up resistance Clock output (71/90/96/114MHz switchable output) CLK2 output enable. Built-in pull-up resistance (HIGH = enable, LOW = disable) Digital supply ground 1 Digital supply voltage 1 Digital supply voltage 1 Clock output (48/96MHz switchable output) Digital supply ground 2 Digital supply voltage 2 Clock output (14.318/17.734MHz switchable output) Test pin 2. Built-in pull-down resistance (leave open circuit or connect to VSS) Description
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SM8721AB
ABSOLUTE MAXIMUM RATINGS
VDD = (VDD1, VDD2, VDD3), VSS = (VSS1, VSS2, VSS3) unless otherwise noted.
Parameter Supply voltage range Supply voltage deviation Input voltage range Output voltage range Power dissipation*1 Storage temperature range Symbol VDD1, VDD2, VDD3 VDD1 - VDD2, VDD1 - VDD3, VDD2 - VDD3 VIN VOUT PD TSTG Rating -0.3 to 6.5 0.1 -0.3 to VDD + 0.3 -0.3 to VDD + 0.3 215 -55 to 125 Unit V V V V mW C
*1. The power dissipation rating is for a surface-mounted device operating at 85C.
RECOMMENDED OPERATING CONDITIONS
VSS = (VSS1, VSS2, VSS3) = 0V, unless otherwise noted.
Rating Parameter Supply voltage*1 Output load capacitance Master clock frequency Operating temperature Symbol VDD1, VDD2, VDD3 CL fXTAL1 fXTAL2 TOPR All outputs excluding XTO XTAL_SEL = LOW XTAL_SEL = HIGH Conditions min 3.0 - - - -40 typ - - 14.318182 28.636363 - max 3.6 15 - - +85 V pF MHz MHz C Unit
*1. The supply voltages are with reference to VSS = 0V. It is recommended that the voltages applied to pins VDD1, VDD2, VDD3 be supplied from a single source. If various voltage sources are used on pins VDD1, VDD2, VDD3, the voltage supplies should be applied simultaneously. If the timing of applying voltage supplies varies, the device may be damaged.
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SM8721AB
ELECTRICAL CHARACTERISTICS
DC Characteristics
VDD = (VDD1, VDD2, VDD3) = 3.3 0.3V, VSS = (VSS1, VSS2, VSS3) = 0V, Ta = -40 to +85C unless otherwise noted.
Rating Parameter Symbol Pins Conditions min Current consumption IDD VIH VIL IIH1 IIL1 Input current IIH2 IIL2 IIH3 IIL3 Output voltage VOH VOL CLK1, CLK2, REF_CLK XTI VDD XTAL_SEL, FS1, FS2, FS3, CLK2ON, TEST1, TEST2*1,*2 XTAL_SEL, FS1, FS2, FS3, CLK2ON*1 TEST1, TEST2*2 VDD = 3.3V, Ta = 25C, all outputs operating without load VDD = 3.3V VIN = VDD VIN = 0V VIN = VDD VIN = 0V VIN = VDD VIN = 0V IOH = -2mA IOL = 2mA - 0.8VDD - - -100 - -1 - -40 VDD - 0.4 - typ 40 - - - - - - - - - - max 50 - 0.2VDD 1 - 100 - 40 - - 0.4 mA V V A A A A A A V V Unit
Input voltage
*1. XTAL_SEL, FS1, FS2, FS3, CLK2ON pins have Schmitt-trigger inputs with internal pull-up resistance. *2. TEST1, TEST2 pins have Schmitt-trigger inputs with internal pull-down resistance.
SEIKO NPC CORPORATION --4
SM8721AB
AC Characteristics
VDD = (VDD1, VDD2, VDD3) = 3.3 0.3V, VSS = (VSS1, VSS2, VSS3) = 0V, Ta = -40 to +85C unless otherwise noted.
Rating Parameter Output clock rise time*1 Output clock fall time*1 Symbol Pins CLK1, CLK2, REF_CLK CLK1, CLK2, REF_CLK CLK1, CLK2, REF_CLK CLK1, CLK2, REF_CLK CLK1, CLK2, REF_CLK CLK1 CLK1, CLK2, REF_CLK Conditions min tr tf tjitter (1-sigma) tjitter (peak-peak) Dt1 Output clock duty cycle*1, *3 Dt2 Power-up time*3,*4,*5 tP CL = 15pF, VOL = 0.2VDD to VOH = 0.8VDD transition CL = 15pF, VOH = 0.8VDD to VOL = 0.2VDD transition Ta = 25C, CL = 15pF, VO = 0.5VDD Ta = 25C, CL = 15pF, VO = 0.5VDD Ta = 25C, CL = 15pF, VO = 0.5VDD Ta = 25C, CL = 15pF, VO = 0.5VDD, 114.54546MHz - - - - 45 40 - typ 2.0 2.0 30 180 50 50 1 max - - - - 55 60 5 ns ns ps ps % % ms Unit
Output clock jitter*2,*3
*1. Measured using the circuit shown in figure 1 on the NPC standard evaluation board. *2. Measured using the circuit shown in figure 2 on the NPC standard evaluation board. *3. The crystal oscillator element coefficients for characteristics measurements are described below (HP4195 measurement equipment). f = 14.318182MHz crystal: R = 12.16, L = 10.34mH, Ca = 11.95fF, Cb = 4.03pF f = 28.636363MHz crystal: R = 12.50, L = 5.89mH, Ca = 5.25fF, Cb = 1.65pF
Cb
L
Ca
R
*4. The power-up time is the time from when the supply reaches 3.0V after the supply is turned ON until each output clock reaches its designated frequency to within 0.1%. *5. Measured using the NPC standard evaluation board.
14.318182/ 28.636363MHz
14.318182/ 28.636363MHz
DUT
Active Probe (HP1152A)
Oscilloscope (Infinium HP54845A) Frequency & Time Interval Analyzer (HP5371A)
DUT
Active Probe (HP1152A)
DUT:Device under test Passive Probe (HP10435A)
Oscilloscope (Infinium HP54845A)
Jitter Measurement System (ASA, M1)
DUT:Device under test
Figure 1. Measurement circuit 1
Figure 2. Measurement circuit 2
SEIKO NPC CORPORATION --5
SM8721AB
FUNCTIONAL DESCRIPTION
14.318182/28.636363MHz Master Clock
The 14.318182/28.636363MHz master clock is generated by the crystal oscillator formed by connecting a crystal (14.318182/28.636363MHz fundamental frequency) between pins XTI (pin 4) and XTO (pin 5), as shown in figure 3.
14.318182/ 28.636363MHz
C1
XTI (Pin 4) Selector Oscillator 1/2 PLL
C2 C1, C2 = 0 to 33pF
XTO (Pin 5) Selector REF_CLK (Pin 19)
Figure 3. Crystal oscillator connection
SEIKO NPC CORPORATION --6
SM8721AB
Output Clock Frequency
The SM8721AB generates 3 output clocks with frequency 14.318182/17.734450MHz (REF_CLK), 71.877274/90.314686/96.016044/114.54546MHz (CLK1), and 48.008022/96.016044MHz (CLK2), derived from the master clock. A list of the supported clock frequency and control settings is shown in table 1.
Table 1. Output clock frequency 14.318182MHz master clock frequency: XTAL_SEL = LOW 28.636363MHz master clock frequency: XTAL_SEL = HIGH
Output clock frequency [MHz] FS1 (Pin 10) HIGH HIGH LOW HIGH HIGH LOW LOW HIGH HIGH HIGH LOW LOW HIGH LOW LOW HIGH HIGH LOW HIGH HIGH LOW LOW LOW HIGH HIGH LOW LOW HIGH LOW LOW 17.734450 14.318182 114.54546 17.734450 14.318182 71.877274 17.734450 Fixed LOW 14.318182 90.314686 17.734450 17.734450 14.318182 96.016044 14.318182 114.54546 96.016044 17.734450 14.318182 71.877274 17.734450 14.318182 90.314686 48.008022 17.734450 FS2 (Pin 9) FS3 (pin 8) CLK2ON (pin 12) REF_CLK (Pin 19) 14.318182 96.016044 CLK1 (Pin 11) CLK2 (Pin 16)
SEIKO NPC CORPORATION --7
SM8721AB
Please pay your attention to the following points at time of using the products shown in this document. The products shown in this document (hereinafter "Products") are not intended to be used for the apparatus that exerts harmful influence on human lives due to the defects, failure or malfunction of the Products. Customers are requested to obtain prior written agreement for such use from SEIKO NPC CORPORATION (hereinafter "NPC"). Customers shall be solely responsible for, and indemnify and hold NPC free and harmless from, any and all claims, damages, losses, expenses or lawsuits, due to such use without such agreement. NPC reserves the right to change the specifications of the Products in order to improve the characteristic or reliability thereof. NPC makes no claim or warranty that the contents described in this document dose not infringe any intellectual property right or other similar right owned by third parties. Therefore, NPC shall not be responsible for such problems, even if the use is in accordance with the descriptions provided in this document. Any descriptions including applications, circuits, and the parameters of the Products in this document are for reference to use the Products, and shall not be guaranteed free from defect, inapplicability to the design for the mass-production products without further testing or modification. Customers are requested not to export or re-export, directly or indirectly, the Products to any country or any entity not in compliance with or in violation of the national export administration laws, treaties, orders and regulations. Customers are requested appropriately take steps to obtain required permissions or approvals from appropriate government agencies.
SEIKO NPC CORPORATION
15-6, Nihombashi-kabutocho, Chuo-ku, Tokyo 103-0026, Japan Telephone: +81-3-6667-6601 Facsimile: +81-3-6667-6611 http://www.npc.co.jp/ Email: sales@npc.co.jp
NC0120BE 2006.04
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