- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄383541 > MAX9242GUM (MAXIM INTEGRATED PRODUCTS INC) 21-Bit Deserializers with Programmable Spread Spectrum and DC Balance PDF資料下載
參數(shù)資料
| 型號： | MAX9242GUM |
| 廠商： | MAXIM INTEGRATED PRODUCTS INC |
| 元件分類： | 通用總線功能 |
| 英文描述： | 21-Bit Deserializers with Programmable Spread Spectrum and DC Balance |
| 中文描述： | LINE DRIVER, PDSO48 |
| 封裝： | PLASTIC, TSSOP-48 |
| 文件頁數(shù)： | 13/22頁 |
| 文件大小： | 306K |
| 代理商： | MAX9242GUM |
M
21-Bit Deserializers with Programmable
Spread Spectrum and DC Balance
______________________________________________________________________________________
13
Detailed Description
The MAX9242/MAX9244/MAX9246/MAX9254 deserialize
three LVDS serial-data inputs into 21 single-ended LVC-
MOS/ LVTTL outputs. The outputs are programmable for
no spread or for a spread of ±2% or ±4%, relative to the
LVDS input clock frequency. The MAX9242/MAX9244/
MAX9254 operate at a parallel clock frequency of 16MHz
to 34MHz in DC-balanced mode and 20MHz to 40MHz in
non-DC-balanced mode. The MAX9246 operates at a
6MHz-to- 18MHz parallel clock frequency in DC-balanced
mode and 8MHz-to-20MHz parallel clock frequency in
non-DC-balanced mode. DC-balanced or non-DC-bal-
anced operation is controlled by the DCB input. The
MAX9242 has a rising-edge strobe and the MAX9244/
MAX9246/MAX9254 have a falling-edge strobe.
DC Balance (DCB)
DC-balanced or non-DC-balanced operation is con-
trolled by the DCB input (see Table 1). In the non-DC-
balanced mode, each channel deserializes 7 bits every
cycle of the parallel clock. In DC-balanced mode, 9 bits
are deserialized every clock cycle (7 data bits + 2
DC-balanced bits). The highest serial-data rate on each
channel in DC-balanced mode is 34MHz x 9 = 306Mbps.
In non-DC-balanced mode, the maximum data rate is
40MHz x 7 = 280Mbps.
Data coding by the MAX9209/MAX9213 serializers (that
are companion devices to the MAX9242/MAX9244/
MAX9246/MAX9254 deserializers) limits the imbalance
of ones and zeros transmitted on each channel. If +1 is
assigned to each binary 1 transmitted and -1 is
assigned to each binary 0 transmitted, the variation in
the running sum of assigned values is called the digital
sum variation (DSV). The maximum DSV for the data
channels is 10. At most, 10 more zeros than ones, or 10
more ones than zeros, are ever transmitted. The maxi-
mum DSV for the clock channel is 5. Limiting the DSV
and choosing the correct coupling capacitors maintain
differential signal amplitude and reduces jitter due to
droop on AC-coupled links.
To obtain DC balance on the data channels, the serial-
izer parallel data is inverted or not inverted, depending
on the sign of the digital sum at the word boundary.
Two complementary bits are appended to each group
of 7 parallel-input data bits to indicate to the MAX9242/
MAX9244/MAX9246/MAX9254 deserializer whether the
data bits are inverted (see Figures 11 and 12). The
deserializer restores the original state of the parallel
data. The LVDS clock signal alternates duty cycles of
4/9 and 5/9 to maintain DC balance.
Spread-Spectrum Generator (SSG)
The MAX9242/MAX9244/MAX9246/MAX9254 single-
ended data and clock outputs are programmable for a
variation of ±2% or ±4% around the LVDS input clock fre-
quency. The modulation rate of the frequency variation is
32.48kHz for a 33MHz LVDS clock input and scales lin-
early with the input clock frequency (see Table 2). The
spread spectrum can also be turned off. The output
spread is controlled through the SSG input (see Table 3).
Table 1. DCB Function
DCB INPUT LEVEL
High
Mid
Low
FUNCTION
Non-DC-balanced mode
Reserved
DC-balanced mode
TxIN_ IS DATA FROM THE SERIALIZER.
TxIN1
TxIN7
TxIN8
TxIN14
TxIN15
+
-
RxCLKIN
CYCLE N + 1
CYCLE N
CYCLE N - 1
TxIN2
TxIN6
TxIN3
TxIN4
TxIN5
TxIN9
TxIN13
TxIN10
TxIN11
TxIN12
TxIN0
TxIN1
TxIN2
TxIN6
TxIN3
TxIN4
TxIN5
TxIN7
TxIN8
TxIN9
TxIN13
TxIN10
TxIN11
TxIN12
TxIN14
TxIN15
TxIN16
TxIN20
TxIN17
TxIN18
TxIN19
TxIN0
TxIN1
TxIN7
TxIN8
TxIN14
TxIN15
TxIN16
TxIN20
TxIN17
TxIN18
TxIN19
TxIN0
RxIN1
RxIN0
RxIN2
Figure 11. Deserializer Serial Input in Non-DC-Balanced Mode
相關PDF資料 |
PDF描述 |
|---|---|
| MAX9244GUM | 21-Bit Deserializers with Programmable Spread Spectrum and DC Balance |
| MAX9246EUM | 21-Bit Deserializers with Programmable Spread Spectrum and DC Balance |
| MAX9246GUM | 21-Bit Deserializers with Programmable Spread Spectrum and DC Balance |
| MAX9254 | 21-Bit Deserializers with Programmable Spread Spectrum and DC Balance |
| MAX9254EUM | 21-Bit Deserializers with Programmable Spread Spectrum and DC Balance |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| MAX9242GUM/V+ | 功能描述:串行器/解串器 - Serdes 21-Bit DC-Balanced LVDS Deserializer 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 |
| MAX9242GUM/V+T | 功能描述:串行器/解串器 - Serdes 21-Bit DC-Balanced LVDS Deserializer 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 |
| MAX9242GUM+D | 功能描述:串行器/解串器 - Serdes 21-Bit DC-Balanced LVDS Deserializer 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 |
| MAX9242GUM+TD | 功能描述:串行器/解串器 - Serdes 21-Bit DC-Balanced LVDS Deserializer 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 |
| MAX9244 | 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:21-Bit Deserializers with Programmable Spread Spectrum and DC Balance |
發(fā)布緊急采購，3分鐘左右您將得到回復。