參數(shù)資料
型號: LM2502SM
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 通用總線功能
英文描述: Mobile Pixel Link (MPL) Display Interface Serializer and Deserializer
中文描述: LINE TRANSCEIVER, PBGA49
封裝: 4 X 4 MM, 1 MM HEIGHT, 0.50 MM PITCH, LEAD FREE, UFBGA-49
文件頁數(shù): 22/27頁
文件大?。?/td> 1089K
代理商: LM2502SM
Application Information
(Continued)
MPL SWAP FEATURE
The LM2502 provides a swap function of MPL MD lines
depending upon the state of the M/S* pin. This facilitates a
straight through MPL interface design eliminating the needs
for via and crossovers as shown on
Figure 17
. See also
Connection Diagram and
Table 1
.
Note that three pins are defined differently on the MAS-
TER and the SLAVE configured device. Schematic Cap-
ture device diagrams should take this into account for
proper connection. The following pin descriptions apply
for the three pins given in Ball Number : Master (Slave)
function
UFBGA Package
A5 : INTR (CLKDIS*)
A6 : MD1 (MD0)
B7 : MD0 (MD1)
LLP Package
34 : INTR (CLKDIS*)
32 : MD1 (MD0)
29 : MD0 (MD1)
FLEX CIRCUIT RECOMMENDATIONS
The three MPL lines should generally run together to mini-
mize any trace length differences (skew). For impedance
control and also noise isolation (crosstalk), guard ground
traces are recommended in between the signals. Commonly
a Ground-Signal-Ground (GSGSGSG) layout is used. Lo-
cate fast edge rate and large swing signals further away to
also minimize any coupling (unwanted crosstalk). In a
stacked flex interconnect, crosstalk also needs to be taken
into account in the above and below layers (vertical direc-
tion). To minimize any coupling locate MPL traces next to a
ground layer. Power rails also tend to generate less noise
than LVCMOS so they are also good candidates for use as
isolation and separation.
The interconnect from the Master to the Slave typically acts
like a transmission line. Thus impedance control and ground
returns are an important part of system design. Impedance
should be in the 50 to 100 Ohm nominal range for the
LM2502. Testing has been done with cables ranging from 40
to 110 Ohms without error (BER Testing). To obtain the
impedance, adjacent grounds are typically required ( 1 layer
flex), or a ground shield / layer. Total interconnect length is
intended to be in the 20cm range, however 30cm is possible
at lower data rates. Skew should be less than 500ps to
maximize timing margins.
GROUNDING
While the LM2502 employs three separate types of ground
pins, these are intended to be connected together to a
common ground plane. The separate ground pins help to
isolate switching currents from different sections of the inte-
grated circuit (IC). Also required is a nearby signal return
(ground) for the MPL signals. These should be provided next
to the MPL signals, as that will create the smallest current
loop area. The grounds are also useful for noise isolation
and impedance control.
PCB RECOMMENDATIONS
General guidelines for the PCB design:
Floor plan, locate MPL Master near the connector to limit
chance of cross talk to high speed serial signals.
Route serial traces together, minimize the number of
layer changes to reduce loading.
Use ground lines are guards to minimize any noise cou-
pling (guarantees distance).
Avoid parallel runs with fast edge, large LVCMOS swings.
Also use a GSGSG pinout in connectors (Board to Board
or ZIF).
Slave device - follow similar guidelines.
Bypass the device with MLC surface mount devices and
thinly separated power and ground planes with low induc-
tance feeds.
High current returns should have a separate path with a
width proportional to the amount of current carried to
minimize any resulting IR effects.
20093320
FIGURE 17. MPL Interface Layout - UFBGA Example
L
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LM2502SM/NOPB 功能描述:串行器/解串器 - Serdes RoHS:否 制造商:Texas Instruments 類型:Deserializer 數(shù)據(jù)速率:1.485 Gbit/s 輸入類型:ECL/LVDS 輸出類型:LVCMOS 輸入端數(shù)量:1 輸出端數(shù)量:20 工作電源電壓:2.375 V to 2.625 V 工作溫度范圍:0 C to + 70 C 封裝 / 箱體:TQFP-64
LM2502SMX/NOPB 功能描述:串行器/解串器 - Serdes RoHS:否 制造商:Texas Instruments 類型:Deserializer 數(shù)據(jù)速率:1.485 Gbit/s 輸入類型:ECL/LVDS 輸出類型:LVCMOS 輸入端數(shù)量:1 輸出端數(shù)量:20 工作電源電壓:2.375 V to 2.625 V 工作溫度范圍:0 C to + 70 C 封裝 / 箱體:TQFP-64
LM2502SQ 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Mobile Pixel Link (MPL) Display Interface Serializer and Deserializer
LM2502SQ/NOPB 功能描述:串行器/解串器 - Serdes RoHS:否 制造商:Texas Instruments 類型:Deserializer 數(shù)據(jù)速率:1.485 Gbit/s 輸入類型:ECL/LVDS 輸出類型:LVCMOS 輸入端數(shù)量:1 輸出端數(shù)量:20 工作電源電壓:2.375 V to 2.625 V 工作溫度范圍:0 C to + 70 C 封裝 / 箱體:TQFP-64
LM2502SQX/NOPB 功能描述:串行器/解串器 - Serdes RoHS:否 制造商:Texas Instruments 類型:Deserializer 數(shù)據(jù)速率:1.485 Gbit/s 輸入類型:ECL/LVDS 輸出類型:LVCMOS 輸入端數(shù)量:1 輸出端數(shù)量:20 工作電源電壓:2.375 V to 2.625 V 工作溫度范圍:0 C to + 70 C 封裝 / 箱體:TQFP-64