參數(shù)資料
型號(hào): L6924U013
廠商: STMICROELECTRONICS
元件分類: 電源管理
英文描述: POWER SUPPLY SUPPORT CKT, PQCC16
封裝: 3 X 3 MM, ROHS COMPLIANT, VFQFPN-16
文件頁數(shù): 3/37頁
文件大?。?/td> 789K
代理商: L6924U013
L6924U
Operation description
Doc ID 14716 Rev 2
11/37
6
Operation description
The L6924U is a fully integrated battery charger that allows a very compact battery
management system for space limited applications. It integrates in a small package all the
power elements: power MOSFET, reverse blocking diode and the sense resistor.
It normally works as a linear charger when powered from an external voltage regulated
adapter or USB port.
However, thanks to its very low minimum input voltage (down to 2.5 V) the L6924U can also
work as a quasi-pulse charger when powered from a current limited adapter. To work in this
condition, it is enough to set the device’s charging current higher than the adapter’s one
(Chapter 6.2: Quasi-pulse mode on page 14). The advantage of the linear charging
approach is that the device has a direct control of the charging current and so the designer
needn’t to rely on power source. However, the advantage of the quasi-pulse approach is that
the power dissipated inside the portable equipment is dramatically reduced.
The L6924U charges the battery in three phases:
Pre-charge constant current: in this phase (active when the battery is deeply
discharged) the battery is charged with a low current (internally set to 10 % of the fast-
charge current).
Fast-charge constant current: in this phase the device charges the battery with the
maximum current (IAC for AC adapter mode, IUSB for USB mode).
Constant voltage: when the battery voltage reaches the selected output voltage, the
device starts to reduce the current, until the charge termination is done.
The full flexibility is provided by:
Programmable fast-charging current (IAC or IUSB) (Chapter 7.3 on page 18).
Programmable end of charge current threshold (IENDTH) (Chapter 7.4 on page 20).
Programmable end of charge timer (TMAXCH) (Chapter 7.7 on page 21).
If a PTC or NTC resistor is used, the device can monitor the battery temperature in order to
protect the battery from operating under unsafe thermal conditions.
Beside the good thermal behavior guaranteed by low thermal resistance of the package,
additional safety is provided by the built-in temperature control loop. The IC monitors
continuously its junction temperature. When the temperature reaches approximately 120 °C,
the thermal control loop starts working, and reduces the charging current, in order to keep
the IC junction temperature at 120 °C.
Two open collector outputs are available for diagnostic purpose (status pins ST1 and ST2).
They can be also used to drive external LEDs or to interface with a microcontroller. The
voltage across the resistor connected between IEND and GND gives information about the
actual charging current (working as a gas gauge), and it can be easily fed into a
microcontroller ADC.
Battery disconnection control is provided thanks to the differentiated sensing and forcing
output pins. A small current is sunk and forced through VOUT. If VOSNS doesn’t detect the
battery, the IC goes into a standby mode.
Figure 5 on page 12 shows the real charging profile of a Li-Ion battery, with a fast charge
current of 450 mA (R1 or R2 = 26 kΩ).
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
L6924U013TR 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:USB compatible battery charger system with integrated power switch for Li-Ion/Li-Polymer
L6924UTR 功能描述:電池管理 Battery Charger USB Compatible RoHS:否 制造商:Texas Instruments 電池類型:Li-Ion 輸出電壓:5 V 輸出電流:4.5 A 工作電源電壓:3.9 V to 17 V 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝 / 箱體:VQFN-24 封裝:Reel
L6925 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:HIGH EFFICIENCY MONOLITHIC SYNCHRONOUS STEP DOWN REGULATOR
L6925013TR 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:HIGH EFFICIENCY MONOLITHIC SYNCHRONOUS STEP DOWN REGULATOR
L6925D 功能描述:直流/直流開關(guān)調(diào)節(jié)器 Synchronous Step-Dwn RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5