- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄383875 > T7234 Compliance with the New ETSI PSD Requirement PDF資料下載
參數(shù)資料
| 型號： | T7234 |
| 英文描述： | Compliance with the New ETSI PSD Requirement |
| 中文描述： | 符合新的ETSI PSD的要求 |
| 文件頁數(shù)： | 87/116頁 |
| 文件大?。?/td> | 1056K |
| 代理商： | T7234 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁第81頁第82頁第83頁第84頁第85頁第86頁當(dāng)前第87頁第88頁第89頁第90頁第91頁第92頁第93頁第94頁第95頁第96頁第97頁第98頁第99頁第100頁第101頁第102頁第103頁第104頁第105頁第106頁第107頁第108頁第109頁第110頁第111頁第112頁第113頁第114頁第115頁第116頁
Data Sheet
January 1998
T7256 Single-Chip NT1 (SCNT1) Transceiver
Lucent Technologies Inc.
83
Questions and Answers
(continued)
U-Interface
(continued)
A12:
(continued)
It is desirable to express the return loss in terms of im-
pedance bounds, since an impedance measurement is
relatively simple to make. From the above equation, up-
per and lower bounds on impedance magnitude can be
derived as follows:
Z
O
= return loss reference impedance = 135
Z
U
= upper impedance curve
Z
L
= lower impedance curve
Upper bound (Z
U
>
Z
O
)
:
RL (dB) = 20 log
Lower bound (Z
L
< Z
O
):
RL (dB) = 20 log
Note that the higher the minimum return loss require-
ment, the tighter the impedance limits will be around
Z
O
, and vice versa.
So, for the upper bound, solve for Z
U
:
For the lower bound, solve for Z
L
:
Plotting the above equations (using 135 for Zo and Fig-
ure 16 in T1.601 for the RL values) results in the graph
shown in Figure 32, which shows the return loss
expressed in terms of impedance upper and lower
bounds.
Q13:
Why must secondary protection, such as a SGS-
Thomson SM6T6V8CA protection diode, be
used
A13:
The purpose of the diode is to protect against
metallic surges below the breakdown level of the
primary protector.
Such metallic surges can be coupled through the
transformer and could cause device damage if
the currents are high. The protector does not pro-
vide absolute protection for the device, but it
works in conjunction with the built-in protection
on the device leads.
The breakdown voltage level for secondary pro-
tection devices must be chosen to be above the
normal working voltage of the signal and typically
below the breakdown voltage level of the next
stage of protection. The SM6T6V8CA has a mini-
mum breakdown voltage level of 6.4 V and a
maximum breakdown voltage of 7.1 V.
The chip pins that the SM6T6V8CA protects are
pins 36 (HP), 31 (HN), 32 (LOP), and 35 (LON).
The 16.9
resistors will help to protect pins 32
and 35, but pins 31 and 36 will be directly
exposed to the voltage across the SM6T6V8CA.
The on-chip protection on these pins consists of
output diodes and a pair of polysilicon resistors.
These pins have been thoroughly tested to
ensure that a 7.1 V level will not damage them;
therefore, no third level of protection is needed
between the SM6T6V8CA and the HP and HN
pins.
The SM6T6V8CA has a maximum reverse surge
voltage level of 10.5 V at 57 A. Sustained cur-
rents this large on the device side of the trans-
former are not a concern in this application.
Thus, there should never be more than 7.1 V
across the SM6T6V8CA, except for possibly an
ESD or lightning hit. In these cases, the T7256 is
able to withstand at least
±
1000 V (human-body
model) on its pins.
Z
Z
U
U
Z
O
–
--------------Z
Z
O
Z
U
Z
L
Z
L
+
–
--------------------
Z
U
Z
O
10
20
1
+
10
20
1
–
----------------------
Z
O
1
-------------------------
10
-20
+
1
10
-20
–
=
=
Z
U
Z
O
10
20
1
10
20
1
+
------------------------
Z
O
1
--------------------------
10
--20
1
10
-20
+
=
=
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| T7234A | Compliance with the New ETSI PSD Requirement |
| T7237A | Compliance with the New ETSI PSD Requirement |
| T7256A | Compliance with the New ETSI PSD Requirement |
| T7288 | CEPT/E1 Line Interface(CEPT/E1 線接口) |
| T7290A | DS1/T1/CEPT/E1 Line Interface(DS1/T1/CEPT/E1 線接口) |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| T7234A | 制造商:AGERE 制造商全稱:AGERE 功能描述:Compliance with the New ETSI PSD Requirement |
| T7237 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Compliance with the New ETSI PSD Requirement |
| T7237A | 制造商:AGERE 制造商全稱:AGERE 功能描述:Compliance with the New ETSI PSD Requirement |
| T7240 | 制造商:TE Connectivity 功能描述: |
| T7-241A5 | 功能描述:撥動(dòng)開關(guān) ON NONE OFF 2 Pole Standard Bat Handle RoHS:否 制造商:OTTO 觸點(diǎn)形式: 開關(guān)功能: 電流額定值: 電壓額定值 AC: 電壓額定值 DC: 功率額定值: 端接類型: 安裝風(fēng)格: 端子密封: 觸點(diǎn)電鍍: 照明: |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。