參數(shù)資料
型號: 935270457518
廠商: NXP SEMICONDUCTORS
元件分類: 電源管理
英文描述: 4-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8
封裝: 3.90 MM, PLASTIC, MS-012, SOT-96, SO-8
文件頁數(shù): 8/12頁
文件大?。?/td> 118K
代理商: 935270457518
Philips Semiconductors
Product data
NE57606
2 to 4 cell redundant Lithium-ion overcharge monitor
2002 Oct 10
5
TECHNICAL DISCUSSION
The NE57606 is typically used in conjunction with a Li-ion protection
IC as redundant protection for a 2, 3, or 4-cell lithium-ion battery
pack. Lithium-ion cells can present a safety hazard if they become
overcharged, therefore careful monitoring of each cell’s operating
point is necessary. For very safety-sensitive applications, a back-up
protection circuit using a device such as the NE57606 is advisable.
The NE57606 monitors each cell within a 2-4 Li-ion cell battery
pack. If any cell within the battery pack exceeds the full-charge
threshold voltage, the overvoltage fault status output assumes a low
state. This output signal should be used to alert other parts of the
system that an overcharged state has been reached. This output
could also be used to open a MOSFET placed in series with the
positive battery terminal to interrupt the charging current from the
battery charger.
Redundant Protection of a Lithium-ion Battery
Pack
Within a typical Li-ion battery system, there are two or three major
circuits responsible for the monitoring and maintenance of the Li-ion
cells: the Li-ion battery charger, the Li-ion protection circuit, and
sometimes the redundant Li-ion overcharge detector. This type of
system is called a triple-redundant protected system. If any one of
the protection circuits fail, then there will be two other independent
systems to assume the protection function. If the product is
designed properly, that is, component de-rating, non-cascading
failure modes, ESD, packaging, etc, having two or more
simultaneous failures within the protection system is virtually
impossible.
During normal operation of the Li-ion system, the battery charger
should be the circuit that terminates the charge. The Lithium-ion
protection circuit should never be used for routine termination of the
charging function. It should be viewed as a back-up protection
system in the event of a charger failure. The redundant overcharge
detection IC should disconnect the pack from the charger in the
event that both other systems have failed.
Setting the trip-point voltages are key to the system’s operation.
First, the trip point tolerances should not overlap, or the systems will
not become active in the proper order over large production. The trip
points should be typically set in the following fashion:
1. The battery charger should be set to terminate its charge at a
point just below the cell’s full charge voltage (–1%)
2. The Li-ion protection circuit is set to open the series charge
MOSFET switch at the rated full charge voltage of any of the
cell(s). (
±1%)
3. The redundant overcharge detector is set to issue an alert and/or
disconnect a series charge MOSFET switch when any cell
voltage exceeds the rated full charge voltage (+1%)
With trip-points set as described above, the charger will taper its
charging current until the charging current falls below a certain
current level, after which the charger turns off. Only if the charger
does not or cannot terminate the charging, the protection IC will
open a series MOSFET switch, thus cutting off any charge current.
Lastly, if both the charger and the protection IC were to fail, the
NE57606 will open another series MOSFET.
相關(guān)PDF資料
PDF描述
935270460518 4-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8
935271414518 2-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8
935271415518 2-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8
935271416518 2-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8
93567-250067 INTERCONNECTION DEVICE
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
935270713557 制造商:NXP Semiconductors 功能描述:SUB ONLY IC CHP
935270792551 制造商:NXP Semiconductors 功能描述:IC BUFF DVR TRI-ST 16BIT 56VFBGA
935270792557 制造商:NXP Semiconductors 功能描述:IC BUFF DVR TRI-ST 16BIT 56VFBGA
935270793551 制造商:NXP Semiconductors 功能描述:IC BUS TRCVR 3-ST 16BIT 56VFBGA
935270793557 制造商:NXP Semiconductors 功能描述:IC BUS TRCVR 3-ST 16BIT 56VFBGA