參數(shù)資料
型號(hào): 73M1903-IVTR/F
廠商: Maxim Integrated Products
文件頁數(shù): 37/47頁
文件大?。?/td> 0K
描述: IC MODEM AFE V.22BIS 20-TSSOP
產(chǎn)品培訓(xùn)模塊: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
標(biāo)準(zhǔn)包裝: 2,000
通道數(shù): 2
電壓 - 電源,模擬: 3 V ~ 3.6 V
電壓 - 電源,數(shù)字: 3 V ~ 3.6 V
封裝/外殼: 20-TSSOP(0.173",4.40mm 寬)
供應(yīng)商設(shè)備封裝: 20-TSSOP
包裝: 帶卷 (TR)
73M1903 Data Sheet
DS_1903_032
42
Rev. 2.1
Appendix B – Crystal Oscillator
The crystal oscillator is designed to operate over wide choice of crystals (from 9 MHz to 27 MHz). The
crystal oscillator output is input to an NCO based pre-scaler (divider) prior to being passed onto an on-
chip PLL. The intent of the pre-scaler is to convert the crystal oscillator frequency, Fxtal, to a convenient
frequency to be used as a reference frequency, Fref, for the PLL. A set of three numbers– Pdvsr (5 bit),
Prst (3 bit) and Pseq (8 bit) must be entered through the serial port as follows:
Pdvsr = Integer [Fref/Fxtal];
Prst = Denominator of the ratio (Fref/Fxtal) minus 1 when it is expressed as a ratio of two smallest
integers = Nnco1/Dnco1;
Pseq = Divide Sequence
Fxtal
mux
count ctrl
overflow
Counter
Pdvsr
Pdvsr +1
Sequence
Register
Rst
Sequence
Counter
Fref
Pseq[7:0]
Prst[2:0]
Figure 17: NCO Block Diagram
Note that in all cases, pre-scaler should be designed such that pre-scaler output frequency, Fref, is in the
range of 2 ~ 4 MHz.
In the first example below, the exact divide ratio required is Fxtal/Fref = 15.625 =125/8. If a divide
sequence of {
÷16,÷16,÷15,÷16,÷16,÷15,÷16,÷15} is repeated, the effective divide ratio would be exactly
15.625. Consequently, Pdvsr of 15, the length of the repeating pattern, Prst = 8 –1 =7, and the pattern,
{1,1,0,1,1,0,1,0}, where 0 means Pdvsr, or
÷15, and 1 means Pdvsr +1, or ÷16 must be entered as below.
Example 1:
Fxtal = 27 MHz, Fref = 1.728 MHz.
Pdvsr = Integer [Fxtal/Fref] = 15 =0Fh
Prst[2:0] = 8 – 1 = 7 from Fxtal/Fref = 15.625 =125/8;
Pseq =
÷16,÷16,÷15,÷16,÷16,÷15,÷16,÷15 => {1,1,0,1,1,0,1,0} =DAh.
In the second example, Fxtal/Fref =4.0. This is a constant divide by 4. Thus Pdvsr is 4, Prst = 1 –1
=0 and Pseq = {x,x,x,x,x,x,x,x).
相關(guān)PDF資料
PDF描述
73M1903C-IMR/F IC MODEM AFE MULTIREGIONAL 32QFN
83336-22 IC PLL INTEGER-N 3GHZ 44CQFJ
8N3Q001EG-105LCDI8 IC CLCK OSC QUAD FREQUENCY 5X7
8N3QV01EG-0109CDI8 IC VCXO LVPECL QD FREQUENCY 5X7
ABFT-40.000MHZ-T2 FREQ TRANSLATOR JITTER ATTEN
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
73M1906B-IM/F 功能描述:電信線路管理 IC DAA-FXO VOLP System Host Side RoHS:否 制造商:STMicroelectronics 產(chǎn)品:PHY 接口類型:UART 電源電壓-最大:18 V 電源電壓-最小:8 V 電源電流:30 mA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VFQFPN-48 封裝:Tray
73M1906B-IM/F1 功能描述:電信線路管理 IC RoHS:否 制造商:STMicroelectronics 產(chǎn)品:PHY 接口類型:UART 電源電壓-最大:18 V 電源電壓-最小:8 V 電源電流:30 mA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VFQFPN-48 封裝:Tray
73M1906B-IMR/F 功能描述:電信線路管理 IC DAA-FXO VOLP System Host Side RoHS:否 制造商:STMicroelectronics 產(chǎn)品:PHY 接口類型:UART 電源電壓-最大:18 V 電源電壓-最小:8 V 電源電流:30 mA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VFQFPN-48 封裝:Tray
73M1906B-IMR/F1 功能描述:電信線路管理 IC RoHS:否 制造商:STMicroelectronics 產(chǎn)品:PHY 接口類型:UART 電源電壓-最大:18 V 電源電壓-最小:8 V 電源電流:30 mA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VFQFPN-48 封裝:Tray
73M1906B-IVT/F 功能描述:電信線路管理 IC DAA-FXO VOLP System Host Side RoHS:否 制造商:STMicroelectronics 產(chǎn)品:PHY 接口類型:UART 電源電壓-最大:18 V 電源電壓-最小:8 V 電源電流:30 mA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VFQFPN-48 封裝:Tray