Figure 9. VRING vs" />

      參數(shù)資料
      型號: SI3232DCX-EVB
      廠商: Silicon Laboratories Inc
      文件頁數(shù): 46/128頁
      文件大?。?/td> 0K
      描述: DAUGHTER CARD W/DISCRETE INTRFC
      標(biāo)準(zhǔn)包裝: 1
      系列: ProSLIC®
      主要目的: 接口,模擬前端(AFE)
      已用 IC / 零件: Si3232
      已供物品: 板,CD
      Si3232
      24
      Preliminary Rev. 0.96
      Not
      Recommended
      fo
      r N
      ew
      D
      esi
      gn
      s
      Figure 9. VRING vs. IRING Characteristic for
      Ground Start Operation
      Figure 8 illustrates the linefeed characteristics for a
      typical application using an ILOOP setting of 24 mA and
      a TIP-RING open circuit voltage (VOC) of 48 V. The
      VOC and VOCTRACK RAM locations are used to
      program the TIP-RING voltage, and these two values
      are equal provided that VBAT > VOC + VOV + VCM. When
      the battery voltage drops below that point, VOCTRACK
      decreases at the same rate as VBAT in order to provide
      sufficient headroom to accommodate both VOV and VCM
      levels below VBAT.
      The equation for calculating the RAM address value for
      VOC, VCM, VOCDELTA, VOV, VOVRING, RINGOF,
      VOCLTH, and VOCHTH is shown below. The CEILING
      function rounds up the result to the next integer.
      For example, to program a VOC value of 51 V:
      During the on-hook state, the Si3232 is in the constant-
      voltage operating area and typically presents a 640
      output impedance (Figure 8). The Si3232 includes a
      special modified linefeed scheme that adjusts the
      ProSLIC’s output impedance based on the linefeed
      voltage level in order to ensure the ability to source
      extended loop lengths. When the terminal equipment
      transitions to the off-hook state, the linefeed voltage
      typically collapses and transitions through the preset
      threshold voltage causing the Si3232 to reduce its
      output impedance to 320
      . The TIP-RING voltage will
      then continue decreasing until the preset loop current
      limit (ILIM) setting is reached. Loop closure and ring trip
      detection thresholds are programmable, and internal
      debouncing is provided. A high-gain common-mode
      loop generates a low impedance from TIP or RING to
      ground, effectively reducing the effects of longitudinal
      interference.
      For ground-start operation, the active lead presents a
      640
      output impedance during the on-hook state and a
      320
      output impedance in the off-hook state. The
      “open” lead presents a high-impedance feed (>150 k
      ).
      Figure 9 illustrates a typical ground-start application
      using VOC = 48 V and ILIM = 24 mA in the TIP OPEN
      state.
      The
      ring
      ground-detection
      threshold
      and
      debouncing interval are both programmable.
      Figure 10. VTIP–RING vs. ILOOP Characteristics
      using Modified Linefeed Scheme
      The modified linefeed scheme also allows the user to
      modify the apparent VOC voltage as a means of
      boosting the linefeed voltage when the battery voltage
      drops below a certain level. Figure 10 illustrates a
      typical Si3232 application sourcing a loop from a 48 V
      battery.
      For
      VOV and VCM values of 3 V, the
      VOCTRACK RAM location will be set to 42 V when
      given a programmed value of 42 V for the VOC RAM
      location. When a loop closure event occurs, the TIP-
      RING voltage decreases linearly until it reaches a
      preset voltage threshold that is lower than VOCTRACK
      by an amount programmed into the VOCLTH RAM
      location. Exceeding this threshold causes the Dual
      ProSLIC to increase its “target” VOC level by an amount
      programmed into the VOCDELTA RAM location to
      provide additional overhead for driving the higher-
      impedance loop. In the on-hook condition, the TIP-
      RING voltage increases linearly until it rises above a
      second preprogrammed voltage threshold, which is
      higher than VOCTRACK by an amount programmed
      into the VOCHTH RAM location. This scheme offers the
      ability to drive very long loop lengths while using the
      lowest possible battery voltage. Consult the factory for
      optimal register and RAM location settings for specific
      applications.
      0
      –20
      –40
      –60
      10
      20
      30
      40
      50
      I
      LIM = 24 mA
      R
      O = 600
      I
      RING (mA)
      V
      RI
      N
      G
      (V
      )
      R
      O = 320
      Loop Closure
      Threshold
      RAM VALUE
      2
      CEILING ROUND
      desired voltage
      1.005V
      ----------------------------------------
      512
      5
      ----------
      =
      VOC
      2
      CEILING ROUND
      51 V
      1.005 V
      --------------------
      512
      5
      ----------
      28CEh
      ==
      0
      10
      20
      10
      20
      30
      40
      50
      VTIPRING (V)
      ILIM (mA)
      1930
      load line
      R
      O = 320
      R
      O = 600
      VOCTRACK
      VOCDELTA
      V
      OC
      相關(guān)PDF資料
      PDF描述
      M1AXK-3440K IDC CABLE - MSC34K/MC34F/X
      SI3232PPT0-EVB BOARD EVAL W/SI3200 INTERFACE
      UPZW6101MHD CAP ALUM 100UF 420V 20% RADIAL
      SI3232DC0-EVB DAUGHTER CARD W/SI3200 INTERFACE
      UPZ2D391MHD CAP ALUM 390UF 200V 20% RADIAL
      相關(guān)代理商/技術(shù)參數(shù)
      參數(shù)描述
      SI3232-FQ 功能描述:電信線路管理 IC DUAL CH SLIC 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
      SI3232-FQR 制造商:Silicon Laboratories Inc 功能描述:
      SI3232-G-FQ 功能描述:電信線路管理 IC Dual-Channel SLIC 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
      SI3232-G-FQR 功能描述:電信線路管理 IC Dual-CH SLIC only Internal 65 Vrms 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
      SI3232-G-GQ 功能描述:電信線路管理 IC Dual-Channel SLIC 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