参数资料
型号: MAX4943ELA+T
厂商: Maxim Integrated Products
文件页数: 7/10页
文件大小: 0K
描述: IC CTLR OVP W/FET 7.40V 8-UDFN
标准包装: 2,500
类型: 过压保护控制器
应用: 手机,数码相机,媒体播放器
安装类型: 表面贴装
封装/外壳: 8-WFDFN
供应商设备封装: 8-uDFN(2x2)
包装: 带卷 (TR)
MAX4943–MAX4946/MAX4944L/MAX4945A/MAX4945L/MAX4949
Device Operation
The MAX4943–MAX4946/MAX4949 have an internal
oscillator and charge pump that control the turn-on
of the internal switch. The internal oscillator controls
the timers that enable the turn-on of the charge pump
and controls the state of the open-drain
ACOK
output. If VIN < VUVLO or if VIN >VOVLO, the internal
oscillator remains off, thus disabling the charge pump.
If VUVLO < VIN < VOVLO, the internal charge pump is
enabled. The charge-pump startup, after a 15ms (typ)
internal delay, turns on the internal switch (see Figure 2).
ACOK is held high during startup until the ACOK 30ms
(typ) blanking period expires. At this point, the device is
in its on state.
At any time, if VIN drops below VUVLO or rises above
VOVLO, ACOK is pulled high and the charge pump
is disabled.
Internal Switch
The MAX4943–MAX4946/MAX4949 incorporate an
internal nFET with a 80mΩ (typ) RON. The switch is
internally driven by a charge pump that generates a 5V
voltage above the input voltage. The internal switch is
equipped with 1.2A (min) current-limit protection that
turns off the switch within 10s (typ) during an overcur-
rent fault condition.
Autoretry
The MAX4943–MAX4946 have an overcurrent autoretry
function that turns on the switch again after a 15ms (typ)
retry time (see Figure 3). If the faulty load condition is still
present after the blanking time, the switch turns off again
and the cycle is repeated. The fast turn-off time and
15ms retry time result in a very low duty cycle to keep
power consumption low. If the faulty load condition is not
present, the switch remains on.
Latch
The MAX4944B/MAX4945B/MAX4949 do not have the
autoretry function, and the switch latches off after an
overcurrent fault. The switch remains off until the over-
current fault has been removed. The switch turns back
on when the adapter voltage goes below VUVLO and
then returns to the valid operating range.
Overvoltage-Protection Controllers with
Internal FET
6
_______________________________________________________________________________________
OVLO
UVLO
tINDBC
tON
IN
OUT
ACOK
tINDBC
tOFF
tINDBC
80% VIN
tACOK
tOFF
tACOK
10% VIN
Figure 2. Timing Diagram
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相关代理商/技术参数
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MAX4944BELA+T 功能描述:电流和电力监控器、调节器 Overvoltage-Protect Controller RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel
MAX4944ELA+ 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述:
MAX4944ELA+G65 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述:
MAX4944ELA+T 功能描述:电流和电力监控器、调节器 Overvoltage-Protect Controller RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel
MAX4944ELA+TG65 制造商:Maxim Integrated Products 功能描述: