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參數(shù)資料
| 型號(hào)： | DS1321 |
| 廠商： | MAXIM INTEGRATED PRODUCTS INC |
| 元件分類： | 電源管理 |
| 英文描述： | Flexible Nonvolatile Controller with Lithium Battery Monitor(帶鋰電池監(jiān)控的靈活非易失性控制器) |
| 中文描述： | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDIP16 |
| 封裝： | 0.300 INCH, DIP-16 |
| 文件頁(yè)數(shù)： | 4/12頁(yè) |
| 文件大?。?/td> | 92K |
| 代理商： | DS1321 |
DS1321
022598 4/12
BATTERY VOLTAGE MONITORING
The DS1321 automatically performs periodic battery
voltage monitoring at a factory–programmed time inter-
val of 24 hours. Such monitoring begins within t
REC
after V
CCI
rises above V
CCTP
, and is suspended when
power failure occurs.
After each 24 hour period (t
BTCN
) has elapsed, the
DS1321 connects V
BAT
to an internal 1M
test resistor
(R
INT
) for one second (t
BTPW
). During this one second,
if V
BAT
falls below the factory–programmed battery volt-
age trip point (V
BTP
), the battery warning output BW is
asserted. While BW is active, battery testing will be per-
formed with period t
BTCW
to detect battery removal and
replacement. Once asserted, BW remains active until
the battery is physically removed and replaced by a
fresh cell. The battery is still retested after each V
CC
power–up, however, even if BW was active on power–
down. If the battery is found to be higher than V
BTP
dur-
ing such testing, BW is deasserted and regular 24–hour
testing resumes. BW has an open–drain output driver.
Battery replacement following BW activation is normally
done with V
CCI
nominal so that SRAM data is not lost.
During battery replacement, the minimum time duration
between old battery detachment and new battery
attachment (t
BDBA
) must be met or BW will not deacti-
vate following attachment of the new battery. Should
BW not deactivate for this reason, the new battery can
be detached for t
BDBA
and then re–attached to clear
BW.
NOTE: The DS1321 cannot constantly monitor an
attached battery because such monitoring would drasti-
cally reduce the life of the battery. As a result, the
DS1321 only tests the battery for one second out of
every 24 hours and does not monitor the battery in any
way between tests. If a good battery (one that has not
been previously flagged with BW) is removed between
battery tests, the DS1321 may not immediately sense
the removal and may not activate BW until the next
scheduled battery test. If a battery is then reattached to
the DS1321, the battery may not be tested until the next
scheduled test.
NOTE: Battery monitoring is only a useful technique
when testing can be done regularly over the entire life of
a lithium battery. Because the DS1321 only performs
battery monitoring when V
CC
is nominal, systems
which are powered–down for excessively long periods
can completely drain their lithium cells without receiving
any advanced warning. To prevent such an occurrence,
systems using the DS1321 battery monitoring feature
should be powered–up periodically (at least once every
few months) in order to perform battery testing. Further-
more, anytime BW is activated on the first battery test
after a power–up, data integrity should be checked via
checksum or other technique.
POWER MONITORING
The DS1321 automatically detects out–of–tolerance
power supply conditions and warns a processor–based
system of impending power failure. When V
CCI
falls
below the trip point level defined by the TOL pin
(V
CCTP
), the V
CCI
comparator activates the reset signal
RST. Reset occurs in the range of 4.75 to 4.5 volts (5%
tolerance) when the TOL pin is connected to GND or in
the range of 4.5 to 4.25 volts (10% tolerance) when TOL
is connected to V
CCO
.
RST also serves as a power–on reset during power–up.
After V
CCI
exceeds V
CCTP
, RST will be held active for
200 ms nominal (t
RPU
). This reset period is sufficiently
long to prevent system operation during power–on tran-
sients and to allow t
REC
to expire. RST has an open–
drain output driver.
FRESHNESS SEAL MODE
When the battery is first attached to the DS1321 without
V
CC
power applied, the device does not immediately
provide battery–backup power on V
CCO
. Only after
V
CCI
exceeds V
CCTP
and later falls below both V
CCTP
and V
BAT
will the DS1321 leave Freshness Seal Mode
and provide battery–backup power. This mode allows a
battery to be attached during manufacturing but not
used until after the system has been activated for the
first time. As a result, no battery energy is drained dur-
ing storage and shipping.
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相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DS1321_04 | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:Flexible Nonvolatile Controller with Lithium Battery Monitor |
| DS1321+ | 功能描述:存儲(chǔ)器控制器 Flexible NV Cntlr w/Lithium Battery RoHS:否 制造商:Maxim Integrated |
| DS1321E | 功能描述:IC CTRL NV W/BATT MON 5V 20TSSOP RoHS:否 類別:集成電路 (IC) >> 存儲(chǔ)器 - 控制器 系列:- 標(biāo)準(zhǔn)包裝:45 系列:- 控制器類型:靜態(tài) RAM（SRAM） 電源電壓:4.5 V ~ 5.5 V 工作溫度:0°C ~ 70°C 封裝/外殼:16-SOIC（0.295"，7.50mm 寬） 供應(yīng)商設(shè)備封裝:16-SOIC W 包裝:管件 |
| DS1321E/T&R | 制造商:Maxim Integrated Products 功能描述:NV CONTRL 5V X4 BW&RST 20-TSSOP T&R - Tape and Reel 制造商:Maxim Integrated Products 功能描述:IC CTRL NV W/BATT MON 5V 20TSSOP |
| DS1321E/T&R | 功能描述:IC CTRL NV W/BATT MON 5V 20TSSOP RoHS:否 類別:集成電路 (IC) >> 存儲(chǔ)器 - 控制器 系列:- 標(biāo)準(zhǔn)包裝:45 系列:- 控制器類型:靜態(tài) RAM（SRAM） 電源電壓:4.5 V ~ 5.5 V 工作溫度:0°C ~ 70°C 封裝/外殼:16-SOIC（0.295"，7.50mm 寬） 供應(yīng)商設(shè)備封裝:16-SOIC W 包裝:管件 |
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