參數(shù)資料
型號: 73M1903C-IM
廠商: TERIDIAN SEMICONDUCTOR CORP
元件分類: 消費家電
英文描述: SPECIALTY CONSUMER CIRCUIT, QCC32
封裝: LEAD FREE, QFN-32
文件頁數(shù): 36/45頁
文件大小: 459K
代理商: 73M1903C-IM
73M1903C
Modem Analog Front End
DATA SHEET
Page: 41 of 45
2005 TERIDIAN Semiconductor Corporation
Rev 3.4
Ndvsr = Integer [ Fvco/Fref ] = 19
Nrst = 5 – 1 = 4 from Fvco/Fref = 19.2 = 96/5;
Nseq =
÷19, ÷19, ÷19, ÷19, ÷20 => {0,0,0,0,1} =xxx00001 = 01h.
Example 2: Fs = 8.0kHz or Fvco = 2 x 2304 x 8kHz =36.864MHz, Fref = 2.304MHz.
Ndvsr = Integer [Fvco/Fref] = 16 = 10h;
Nrst= 1-1 = 0 from Fvco/Fref = 16/1;
Nseq = {x,x,x,x,x,x,x,x} = xxh.
Example 3: Fs = 9.6kHz or Fvco = 2 x 2304 x 9.6kHz =44.2368MHz, Fref = 2.4576MHz.
Ndvsr = Integer [Fvco/Fref] = 18 = 16h;
Nrst= 1-1 = 0 from Fvco/Fref = 18/1;
Nseq = {x,x,x,x,x,x,x,x} = xxh.
Example 4: Fs = 16.0kHz or Fvco = 2 x 2304 x 16.0kHz =73.728MHz, Fref = 3.072MHz.
Ndvsr = Integer [Fvco/Fref] = 24 =18h;
Nrst= 1-1 = 0 from Fvco/Fref = 24/1;
Nseq = {x,x,x,x,x,x,x,x} = xxh.
It is important to note that in general the NCO based feedback divider will generate a fixed jitter pattern
whose frequency components are at Fref/Accreset2 and its integer multiples. The overall jitter frequency
will be a nonlinear combination of jitters from both pre-scaler and PLL NCO. The fundamental frequency
component of this jitter is at Fref/Prst/Nrst. The PLL parameters should be selected to remove this jitter.
Three separate controls are provided to fine tune the PLL as shown in the following sections.
To ensure quick settling of PLL, a feature was designed into the 73M1903C where Ichp is kept at a higher
value until Lokdet becomes active or Frcvco bit is set to 1, whichever occurs first. Thus PLL is
guaranteed to have the settling time of less than one Frame Synch period after a new set of NCO
parameters had been written to the appropriate registers. The serial port register writes for a particular
sample rate should be done in sequence starting from register 08h ending in register 0Dh. 0Dh register
should be the last one to be written to. This will be followed by a write to the next register in sequence
(0Eh) to force the transition of Sysclk from Xtal to Pllclk.
Upon the system reset, the system clock is reset to Fxtal/9. The system clock will remain at Fxtal/9 until
the Host forces the transition, but no sooner the second Frame Synch period after the write to 0Dh.
When this happens, the system clock will transition to PLLclk without any glitches thru a specially
designed deglitch MUX.
Examples of NCO settings
Example 1:
Crystal Frequency = 24.576MHz; Desired Sampling Rate, Fs = 13.714kHz(=2.4kHz x 10/7 x 4)
Step 1. First compute the required VCO frequency, Fvco, corresponding to
Fs = 2.4kHz x 10/7 x 4 = 13.714kHz, or
Fvco = 2 x 2304 x Fs = 2 x 2304 x 2.4kHz x 10/7 x 4 = 63.19543MHz.
Step 2. Express the required VCO frequency divided by the Crystal Frequency as a ratio of two integers.
This is initially given by :
相關(guān)PDF資料
PDF描述
73M1903C-IM SPECIALTY CONSUMER CIRCUIT, QCC32
73S1209F-44IM/F POWER SUPPLY MANAGEMENT CKT, QCC44
73S1209F-68IM/F POWER SUPPLY MANAGEMENT CKT, QCC68
73S1209F-68IMR/F POWER SUPPLY MANAGEMENT CKT, QCC68
73S1209F-44IMR/F POWER SUPPLY MANAGEMENT CKT, QCC44
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
73M1903C-IM/F 功能描述:電信線路管理 IC Modem Analog Front End 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 安裝風格:SMD/SMT 封裝 / 箱體:VFQFPN-48 封裝:Tray
73M1903C-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 安裝風格:SMD/SMT 封裝 / 箱體:VFQFPN-48 封裝:Tray
73M1903C-IMR/F 功能描述:電信線路管理 IC Modem Analog Front End 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 安裝風格:SMD/SMT 封裝 / 箱體:VFQFPN-48 封裝:Tray
73M1903C-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 安裝風格:SMD/SMT 封裝 / 箱體:VFQFPN-48 封裝:Tray
73M1903-EVM-600 功能描述:網(wǎng)絡(luò)開發(fā)工具 73M1903 w/Ppu & 600 Ohm Term-Usa & Japan RoHS:否 制造商:Rabbit Semiconductor 產(chǎn)品:Development Kits 類型:Ethernet to Wi-Fi Bridges 工具用于評估:RCM6600W 數(shù)據(jù)速率:20 Mbps, 40 Mbps 接口類型:802.11 b/g, Ethernet 工作電源電壓:3.3 V