PLL BUILDING BLOCK MDS 673-01 L 7 Revision 051310 www.idt" />
參數(shù)資料
型號: ICS673M-01LFT
廠商: IDT, Integrated Device Technology Inc
文件頁數(shù): 7/8頁
文件大?。?/td> 0K
描述: IC PLL BUILDING BLOCK 16-SOIC
標準包裝: 2,500
類型: 鎖相環(huán)路(PLL)
PLL:
輸入: 時鐘
輸出: 時鐘
電路數(shù): 1
比率 - 輸入:輸出: 1:2
差分 - 輸入:輸出: 無/無
頻率 - 最大: 120MHz
除法器/乘法器: 是/無
電源電壓: 3.135 V ~ 5.5 V
工作溫度: 0°C ~ 70°C
安裝類型: 表面貼裝
封裝/外殼: 16-SOIC(0.154",3.90mm 寬)
供應(yīng)商設(shè)備封裝: 16-SOIC
包裝: 帶卷 (TR)
其它名稱: 673M-01LFT
PLL BUILDING BLOCK
MDS 673-01 L
7
Revision 051310
www.idt.com
ICS673-01
Determining the Loop Filter Values
The loop filter components consist of CS, CP, and RS.
Calculating these values is best illustrated by an
example. Using the example in Figure 1, we can
synthesize 20 MHz from a 200 kHz input.
The phase locked loop may be approximately
described by the following equations:
Bandwidth
Damping factor,
where:
KO = VCO gain (Hz/V)
Icp = Charge pump current (A)
N = Total feedback divide from VCO,
including the internal VCO post divider
CS = Loop filter capacitor (Farads)
RS = Loop filter resistor (Ohms)
As a general rule, the bandwidth should be at least 20
times less than the reference frequency, i.e.,
In this example, using the above equation, bandwidth
should be less than or equal to 10 kHz. By setting the
bandwith to 10kHz and using the first equation, RS can
be determined since all other variables are known. In
the example of Figure 1, N = 200, comprising the divide
by 2 on the chip (VCO post divider) and the external
divide by 100. Therefore, the bandwidth equation
becomes:
and RS = 26 kΩ
Choosing a damping factor of 0.7 (a minimal damping
factor than can be used to ensure fast lock time),
damping factor equation becomes:
and CS = 1.32 nF (1.2 nF is the nearest standard
value).
The capacitor CP is used to damp transients from the
charge pump and should be approximately 1/20th the
size of CS, i.e.,
Therefore, CP = 60 pF (56 pF nearest standard value).
To summarize, the loop filter components are:
CS = 1.2 nf
CP = 56 pf
RS = 26 kΩ
When choosing either CLK1 or CLK2 to drive the
feedback divider, IDT recommends that CLK2 be used
so that the rising edges of CLK1, CLK2, and REFIN are
all synchronized. If CLK1 is used to feedback, CLK2
may be either a rising or falling edge when compared to
CLK1 and REFIN.
NBW
R
S
K
O
I
CP
2
πN
--------------------------------
=
ζ
R
S
2
------
K
O
I
CP
C
S
N
-----------------------------------
=
BW
REFIN
() 20
0,000
R
S
190
10
6
2.5
10
2
π
200
--------------------------------------------------------------------
=
0.7
25 000
,
2
----------------
190
10
6
2.5
10
6
C
S
200
--------------------------------------------------------------------------
=
C
P
C
S
20
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ICS673M-01T 功能描述:IC PLL BUILDING BLOCK 16-SOIC RoHS:否 類別:集成電路 (IC) >> 時鐘/計時 - 時鐘發(fā)生器,PLL,頻率合成器 系列:- 產(chǎn)品變化通告:Product Discontinuation 04/May/2011 標準包裝:96 系列:- 類型:時鐘倍頻器,零延遲緩沖器 PLL:帶旁路 輸入:LVTTL 輸出:LVTTL 電路數(shù):1 比率 - 輸入:輸出:1:8 差分 - 輸入:輸出:無/無 頻率 - 最大:133.3MHz 除法器/乘法器:是/無 電源電壓:3 V ~ 3.6 V 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:16-TSSOP(0.173",4.40mm 寬) 供應(yīng)商設(shè)備封裝:16-TSSOP 包裝:管件 其它名稱:23S08-5HPGG
ICS674-01 制造商:ICS 制造商全稱:ICS 功能描述:User Configurable Divider
ICS674R-01 功能描述:IC DIVIDER USER CONFIG 28-SSOP RoHS:否 類別:集成電路 (IC) >> 時鐘/計時 - 時鐘發(fā)生器,PLL,頻率合成器 系列:- 產(chǎn)品變化通告:Product Discontinuation 04/May/2011 標準包裝:96 系列:- 類型:時鐘倍頻器,零延遲緩沖器 PLL:帶旁路 輸入:LVTTL 輸出:LVTTL 電路數(shù):1 比率 - 輸入:輸出:1:8 差分 - 輸入:輸出:無/無 頻率 - 最大:133.3MHz 除法器/乘法器:是/無 電源電壓:3 V ~ 3.6 V 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:16-TSSOP(0.173",4.40mm 寬) 供應(yīng)商設(shè)備封裝:16-TSSOP 包裝:管件 其它名稱:23S08-5HPGG
ICS674R-01I 功能描述:IC DIVIDER USER CONFIG 28-SSOP RoHS:否 類別:集成電路 (IC) >> 時鐘/計時 - 時鐘發(fā)生器,PLL,頻率合成器 系列:- 產(chǎn)品變化通告:Product Discontinuation 04/May/2011 標準包裝:96 系列:- 類型:時鐘倍頻器,零延遲緩沖器 PLL:帶旁路 輸入:LVTTL 輸出:LVTTL 電路數(shù):1 比率 - 輸入:輸出:1:8 差分 - 輸入:輸出:無/無 頻率 - 最大:133.3MHz 除法器/乘法器:是/無 電源電壓:3 V ~ 3.6 V 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:16-TSSOP(0.173",4.40mm 寬) 供應(yīng)商設(shè)備封裝:16-TSSOP 包裝:管件 其它名稱:23S08-5HPGG
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