參數(shù)資料
型號: Si3200-BS
廠商: Electronic Theatre Controls, Inc.
英文描述: DUAL PROGRAMMABLE CMOS SLIC WITH LINE MONITORING
中文描述: 兩個(gè)可編程的CMOS用戶接口與在線監(jiān)測
文件頁數(shù): 34/128頁
文件大?。?/td> 2327K
代理商: SI3200-BS
Si3232
34
Preliminary Rev. 0.96
4.5.2. Ground Key Detection
Ground key detection detects an alerting signal from the
terminal equipment during the tip open or ring open
linefeed states. The functional blocks required to
implement a ground key detector are shown in
Figure 15, and the register set for detecting a ground
key event is provided in Table 22 on page 36. The
primary input to the system is the longitudinal current
sense value provided by the voltage/current/power
monitoring circuitry and reported in the ILONG RAM
address. The I
LONG
value is produced in the ISP
provided the LFS bits in the linefeed register indicate
the device is in the tip open or ring open state.
The longitudinal current (I
LONG
) is computed as shown
in the following equation. Refer to Figure 11 on page 26
for the transistor references used in the equation (Q1,
Q2, Q5 and Q6 – note that the Si3200 has
corresponding MOS transistors). The same I
LONG
equation applies to the discrete bipolar linefeed as well
as the Si3200 linefeed device.
The output of the ISP (I
LONG
) is the input to a
programmable, digital low-pass filter, which removes
unwanted ac signal components before threshold
detection.
The low-pass filter coefficient is calculated using the
following equation and is entered into the LONGLPF
RAM location:
Where f = the desired cutoff frequency of the filter.
The programmable range of the filter is from 0h (blocks
all signals) to 4000h (unfiltered). A typical value of 10
(0A10h) is sufficient to filter out any unwanted ac
artifacts while allowing the dc information to pass
through the filter.
The output of the low-pass filter is compared to the
programmable threshold, LONGHITH. Hysteresis is
enabled
by
programming
LONGLOTH, to detect when the ground key is released.
The threshold comparator output feeds a programmable
debounce filter.
a
second
threshold,
The output of the debounce filter remains in its present
state unless the input remains in the opposite state for
the entire period of time programmed by the loop
closure debounce interval, LONGDBI. If the debounce
interval is satisfied, the LONGHI bit is set to indicate
that a valid ground key event has occurred.
When the Si3220/25 detects a ground key event, the
linefeed automatically transitions from the TIP-OPEN
(or RING-OPEN) state to the FORWARD-ACTIVE (or
REVERSE-ACTIVE) state. However, this automatic
state transition is triggered by the LCR bit becoming
active (i.e., =1), and not by the LONGHI bit.
While I
LONG
is used to generate the LONGHI status bit,
a transition from TIP-OPEN to the FORWARD-ACTIVE
state (or from the RING-OPEN to the REVERSE-
ACTIVE state) occurs when the RING terminal (or TIP
terminal) is grounded and is based on the LCR bit and
implicitly on exceeding the LCROFFHK threshold.
As an example of ground key detection, suppose that
the Si3220/25 has been programmed with the current
values shown in Table 20.
With the settings of Table 20, the behavior of I
LOOP
,
I
LONG
, LCR, LONGHI, and CMHIGH is as shown in
Table 21. The entries under “Loop State” indicate the
condition of the loop, as determined by the equipment
terminating the loop. The entries under “LINEFEED
Setting” indicate the state initially selected by the host
CPU (e.g., TIP-OPEN) and the automatic transition to
the FORWARD-ACTIVE state due to a ground key
event (when RING is connected to GND). The transition
from state #2 to state #3 in Table 21 is the automatic
transition from TIP-OPEN to FWD-ACTIVE in response
to LCR = 1.
I
LONG
I
---------------------------------------+
I
I
2
=
LONGLPF
--------------------------------
800
(
)
2
3
×
=
Table 20. Settings for Ground Key Example
ILIM
21 mA
LCROFFHK
14 mA
LCRONHK
10 mA
LONGHITH
7 mA
LONGLOTH
5 mA
相關(guān)PDF資料
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Si3232 DUAL PROGRAMMABLE CMOS SLIC WITH LINE MONITORING
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參數(shù)描述
SI3200-BSR 制造商:Silicon Laboratories Inc 功能描述:
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SI3200-FSR 制造商:Silicon Laboratories Inc 功能描述:SLIC 2CH 70DB 45MA 3.3V/5V 16SOIC EP - Tape and Reel
Si3200-G-FS 功能描述:射頻無線雜項(xiàng) 100 V Linefeed Inter IC unit price RoHS:否 制造商:Texas Instruments 工作頻率:112 kHz to 205 kHz 電源電壓-最大:3.6 V 電源電壓-最小:3 V 電源電流:8 mA 最大功率耗散: 工作溫度范圍:- 40 C to + 110 C 封裝 / 箱體:VQFN-48 封裝:Reel
SI3200-G-FSR 功能描述:電信線路管理 IC 100 V Linefeed Interface 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