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參數(shù)資料
| 型號： | M48T02-70PC1 |
| 廠商： | 意法半導體 |
| 英文描述： | 16 Kbit 2Kb x8 TIMEKEEPER[ SRAM |
| 中文描述： | 16千位2KB的x8計時器[靜態(tài)存儲器 |
| 文件頁數(shù)： | 12/15頁 |
| 文件大?。?/td> | 94K |
| 代理商： | M48T02-70PC1 |
The second approach is better suited to a manu-
facturing environment, and involves the use of
some test equipment. When the Frequency Test
(FT)bit, the seventh-mostsignificantbit inthe Day
Register,is setto a’1’, andthe oscillatorisrunning
at 32,768 Hz, the LSB (DQ0) of the SecondsReg-
ister will toggle at 512 Hz. Any deviation from512
Hz indicates the degree and direction of oscillator
frequencyshift at the test temperature.For exam-
ple, a reading of 512.01024 Hz would indicate a
+20 ppm oscillator frequency error, requiring a
-10(WR001010) to be loaded into the Calibration
Byte for correction. Note that setting or changing
theCalibration Byte does notaffectthe Frequency
testoutputfrequency.The devicemustbe selected
and address 7F9h must be held constant when
readingthe 512 Hz on DQ0.
TheFTbitmustbesetusingthesamemethodused
to set the clock, usingthe Write bit.TheLSB of the
Seconds Register is monitored by holding the
M48T02/12 in an extended read of the Seconds
Register, without having the Read bit set. The FT
bitMUSTbe resetto ’0’fornormalclockoperations
to resume.
For more informationon calibration,see theAppli-
cationNote AN924 ”TIMEKEEPERCalibration”.
POWER SUPPLY DECOUPLING and UNDER-
SHOOTPROTECTION
I
CC
transients,including those producedby output
switching,canproducevoltagefluctuations,result-
ingin spikeson the V
CC
bus. Thesetransientscan
be reduced if capacitorsare used to store energy,
AI02169
VCC
0.1
μ
F
DEVICE
VCC
VSS
Figure 12. SupplyVoltage Protection
which stabilizesthe V
CC
bus.The energystored in
thebypasscapacitorswillbe releasedas lowgoing
spikes are generated or energy will be absorbed
when overshoots occur. A bypass capacitor value
of 0.1
μ
F (as shown in Figure 12) is recommended
in order to provide the neededfiltering.
In addition to transientsthat are causedby normal
SRAM operation, power cycling can generate
negative voltage spikes on V
CC
that drive it to
values below V
SS
by as muchas one Volt. These
negative spikes can cause data corruption in the
SRAM while in battery backup mode. To protect
from these voltage spikes, it is recommeded to
connecta schottkydiodefromV
CC
toV
SS
(cathode
connected to V
CC
, anode to V
SS
). Schottky diode
1N5817 is recommended for through hole and
MBRS120T3is recommendedfor surfacemount.
CLOCKOPERATION
(cont’d)
12/15
M48T02, M48T12
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相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| M48T02-70PC1 | 制造商:STMicroelectronics 功能描述:IC NVRAM 10 YR BATTERY 16K 48T02 |
| M48T02-70PC1TR | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:5.0V, 16 Kbit (2Kb x 8) TIMEKEEPER㈢ SRAM |
| M48T08 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:5V, 64Kbit (8 Kb x 8) TIMEKEEPER㈢ SRAM |
| M48T08_07 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:5V, 64Kbit (8 Kb x 8) TIMEKEEPER㈢ SRAM |
| M48T08_10 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:5 V, 64 Kbit (8 Kb x 8) TIMEKEEPER?? SRAM |
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