- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄358701 > DS1922L Temperature Logger iButton with 8kB Datalog Memory PDF資料下載
參數(shù)資料
| 型號： | DS1922L |
| 英文描述： | Temperature Logger iButton with 8kB Datalog Memory |
| 文件頁數(shù)： | 41/48頁 |
| 文件大?。?/td> | 428K |
| 代理商： | DS1922L |
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頁當(dāng)前第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁
DS1922L/DS1922T
41 of 48
The sum of t
RL
+ (rise rime) on one side and the internal timing generator of the DS1922L/T on the other side
define the master sampling window (t
MSRMIN
to t
MSRMAX
) in which the master must perform a read from the data line.
For most reliable communication, t
RL
should be as short as permissible and the master should read close to but no
later than t
MSRMAX
. After reading from the data line, the master must wait until t
SLOT
is expired. This guarantees
sufficient recovery time t
REC
for the DS1922L/T to get ready for the next time slot.
IMPROVED NETWORK BEHAVIOR
In a 1-Wire environment line termination is possible only during transients controlled by the bus master (1-Wire
driver). 1-Wire networks, therefore are susceptible to noise of various origins. Depending on the physical size and
topology of the network, reflections from end points, and branch points can add up or cancel each other to some
extent. Such reflections are visible as glitches or ringing on the 1-Wire communication line. Noise coupled onto the
1-Wire line from external sources can also result in signal glitching. A glitch during the rising edge of a time slot can
cause a slave device to lose synchronization with the master and, as a consequence, result in a search ROM
command coming to a dead end or cause a device-specific function command to abort. For better performance in
network applications, the DS1922L/T uses a new 1-Wire front end, which makes it less sensitive to noise and also
reduces the magnitude of noise injected by the slave device itself.
The 1-Wire front end of the DS1922L/T differs from traditional slave devices in four characteristics:
1) The falling edge of the presence pulse has a controlled slew rate. This provides a better match to the line
impedance than a digitally switched transistor, converting the high frequency ringing known from traditional
devices into a smoother low-bandwidth transition. The slew rate control is specified by the parameter t
FPD
,
which has different values for standard and Overdrive speed.
2) There is additional low-pass filtering in the circuit that detects the falling edge at the beginning of a time slot.
This reduces the sensitivity to high-frequency noise. This additional filtering does not apply at Overdrive speed.
3) There is a hysteresis at the low-to-high switching threshold V
TH
. If a negative glitch crosses V
TH
but doesn’t go
below V
TH
- V
HY
, it will not be recognized (Figure 14, Case A). The hysteresis is effective at any 1-Wire speed.
4) There is a time window specified by the rising edge hold-off time t
REH
during which glitches will be ignored,
even if they extend below V
TH
- V
HY
threshold (Figure 14, Case B, t
GL
< t
REH
). Deep voltage droops or glitches
that appear late after crossing the V
TH
threshold and extend beyond the t
REH
window cannot be filtered out and
will be taken as beginning of a new time slot (Figure 14, Case C, t
GL
t
REH
).
Only devices which have the parameters t
FPD
, V
HY
and t
REH
specified in their electrical characteristics use the
improved 1-Wire front end.
Figure 14. Noise Suppression Scheme
V
PUP
V
TH
V
HY
0V
t
REH
t
GL
t
REH
t
GL
Case A
Case C
Case B
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| DS1922T | Temperature Logger iButton with 8kB Datalog Memory |
| DS1922L-F5 | Temperature Logger iButton With 8kB Datalog Memory |
| DS1992 | 1kb/4kb Memory iButton |
| DS1993 | 1kb/4kb Memory iButton |
| DS1992L-F5 | 1kbit/4kbit Memory iButtonTM DS1994 4-kbit Plus Time Memory iButtonTM |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DS1922L_11 | 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:Temperature Logger iButton with 8KB Data-Log Memory |
| DS1922L-F5 | 功能描述:iButton RoHS:否 存儲類型:SRAM 存儲容量:512 B 組織: 工作電源電壓:3 V to 5.25 V 接口類型:1-Wire 最大工作溫度:+ 85 C 尺寸:17.35 mm x 5.89 mm 封裝 / 箱體:F5 MicroCan 制造商:Maxim Integrated |
| DS1922L-F5# | 功能描述:iButton Temp Logger Ibutton w/8Kb Datalog Mem RoHS:否 存儲類型:SRAM 存儲容量:512 B 組織: 工作電源電壓:3 V to 5.25 V 接口類型:1-Wire 最大工作溫度:+ 85 C 尺寸:17.35 mm x 5.89 mm 封裝 / 箱體:F5 MicroCan 制造商:Maxim Integrated |
| DS1922L-F5#A20 | 功能描述:iButton RoHS:否 存儲類型:SRAM 存儲容量:512 B 組織: 工作電源電壓:3 V to 5.25 V 接口類型:1-Wire 最大工作溫度:+ 85 C 尺寸:17.35 mm x 5.89 mm 封裝 / 箱體:F5 MicroCan 制造商:Maxim Integrated |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。