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参数资料
| 型号： | DS2441 |
| 英文描述： | 1-Cell Li-Ion Battery Manager |
| 中文描述： | 1节锂离子电池管理器 |
| 文件页数： | 7/29页 |
| 文件大小： | 134K |
| 代理商： | DS2441 |
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DS2441
7 of 29
Summary.
All of the protection conditions described above are OR'ed together to affect the
CHG
and
DCHG
outputs. Taking the OV, UV and OT bits from the Status Register and considering the OC Status
Register bit to be the logical OR of DOC (discharge overcurrent) and COC (charge overcurrent), the
equations for
CHG
and
DCHG
are as follows:
DCHG
= OT or DOC or UV or Low Power Mode
CHG
= OT or COC or OV or Low Power Mode
LOW POWER MODE
The DS2441 enters Low Power Mode when an undervoltage condition exists on the lithium-ion cell or
when the host system sets the LPM bit in the Control Register. While in Low Power Mode, the DS2441
shuts off the external charge and discharge FETs and turns off most of its internal circuitry to reduce its
load on the cell to I
DD1
(1
μ
A typical). The DS2441 stays in Low Power Mode until it is “awakened” by
the attachment of a charger to the battery pack (voltage on
CHG
pin > VDD) or a high-to-low transition
on the DQ pin. After either stimulus, the DS2441 powers up fully, makes initial measurements with the
charge and discharge FETs off (to prevent charging until it can verify the cell is not overvoltage), and
then returns to its normal mode of operation.
Charging from Low Power Mode.
Charging an undervoltage pack is as simple as applying a charger to
the pack. The presence of the charger automatically triggers the DS2441 to leave Low Power Mode,
make initial measurements with the FETs off, and return to its normal mode of operation. Generally the
DS2441 starts normal operation with the discharge FET off (because the cell is still undervoltage) and the
charge FET on, which allows charging to proceed. If the charger pulls the cell voltage above
undervoltage threshold V
UV
before the expiration of undervoltage delay t
UVD
, the DS2441 remains in its
normal mode of operation and charging can continue. If the cell remains below V
UV
for t
UVD
, the DS2441
shuts off the charge and discharge FETs, asserts the UV flag, and returns to Low Power Mode. Once
back in Low Power Mode, the presence of the charger again triggers the DS2441 to go back to its normal
mode of operation where charging can continue for at least t
UVD
. As long as the charger is applied to the
pack, the DS2441 repeatedly cycles between its normal mode of operation (for t
UVD
) and Low Power
Mode (for approximately 21 ms) until the cell has been charged above V
UV
. After the cell is above V
UV,
the DS2441 remains in its normal mode of operation and charging continues normally.
REFRESHING UNDERVOLTAGE PACKS
In the worst-case undervoltage situation, a battery can be so far discharged that VDD is outside the
specified operating range of the DS2441, leaving the DS2441 without a power supply and unable to allow
the charging necessary to correct the situation. The Refresh bit (RFSH) in the Control Register and the
ability to parasitically steal power from the DQ pin are features that allow any DS2441-based battery
pack to be refreshed from even the deepest undervoltage situation.
Parasite Power.
As is the case for many Dallas 1-Wire products, the DS2441 can, using an on-chip
capacitor, parasitically steal enough power from the DQ line to support register and memory accesses
even with no voltage present on the VDD pin. DQ must be pulled up to at least 3V, and maximum pulse
width specifications must be met to ensure proper parasite-powered operation.
Refresh Bit.
Setting the RFSH bit in the Control Register to logic 1 causes the DS2441 to mask the
effect of undervoltage on the
CHG
output, stay in the normal mode of operation (and out of Low Power
Mode), and power all of its circuitry only from the DQ pin. Because all DS2441 circuitry is powered
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| DS2450 | 1-Wire Quad A/D Converter |
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相关代理商/技术参数 |
参数描述 |
|---|---|
| DS2442 | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Battery Management |
| DS245 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Octal Bus Transceiver |
| DS2450 | 制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:1-Wire Quad A/D Converter |
| DS2450S | 功能描述:模数转换器 - ADC RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
| DS2450S/T&R | 功能描述:模数转换器 - ADC RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
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