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参数资料
| 型号： | MAX1946ETA+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 10/13页 |
| 文件大小： | 0K |
| 描述： | IC USB SW SGL AUTORESET 8TDFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 1 |
| 应用： | USB，外设 |
| 电流 - 电源： | 40µA |
| 电源电压： | 2.7 V ~ 5.5 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 8-WDFN 裸露焊盘 |
| 供应商设备封装： | 8-TDFN-EP（3x3） |
| 包装： | 标准包装 |
| 其它名称： | MAX1946ETA+TDKR |
Single USB Switch with Autoreset and
Fault Blanking in Tiny TDFN
Fault Indicator
The MAX1946 provides an open-drain fault output,
FAULT . Connect FAULT to IN through a 100k ? pullup
resistor for most applications. FAULT asserts low when
any of the following conditions occur:
? The input voltage is below the UVLO threshold.
blanked. Thermal-overload faults and input voltage
drops below the UVLO threshold immediately turn the
switch off and assert FAULT low.
Fault blanking allows the MAX1946 to handle USB
loads that may not be fully compliant with the USB
specification. The MAX1946 successfully powers USB
?
?
The switch junction temperature exceeds the
+160°C thermal-shutdown temperature limit.
The switch is in current-limit or short-circuit current-
limit mode for more than 20ms.
loads with additional bypass capacitance and/or large
startup currents while protecting the upstream power
source. No fault is reported if the switch brings up the
load within the 20ms blanking period. See Table 2 for a
summary of current limit and fault behavior.
The FAULT output deasserts after a 20ms delay once
the fault condition is removed. Ensure that the
MAX1946 input bypass capacitance is sufficiently large
to prevent load glitches from triggering the FAULT out-
put. Limit the input voltage slew rate to 0.2V/μs to pre-
vent erroneous FAULT indications.
To differentiate large capacitive loads from short cir-
cuits or sustained overloads, the MAX1946 has a fault-
blanking circuit. When a load transient causes the
device to enter current limit, an internal counter moni-
tors the duration of the fault. For load faults exceeding
the 20ms fault-blanking time, the switch turns off,
FAULT asserts low, and the device enters autoreset
mode (see the Output Fault Protection and Autoreset
section). Only current-limit and short-circuit faults are
Table 2. Current Limiting and Fault Behavior
CONDITION
Applications Information
Typical Application Circuit
Input Power Supply and Capacitance
Connect both IN inputs together. IN powers the internal
control circuitry and charge pump for the switch.
Bypass IN to GND with a 0.1μF ceramic capacitor.
When driving inductive loads or operating from induc-
tive sources, which may occur when the MAX1946 is
powered by long leads or PC traces, larger input
bypass capacitance is required to prevent voltage
spikes from exceeding the MAX1946’s absolute maxi-
mum ratings during short-circuit events.
MAX1946 BEHAVIOR
? If a short is detected at the output, the switch turns off, and the blanking timer begins. FAULT
remains high during the blanking timeout period.
? If the short persists during the fault-blanking period, the output pulses at 0.35A RMS . If the short is
Output Short Circuit
(V OUT < 1V)
Output Overload Current
(V OUT > 1V)
Thermal Fault
(T J > +160 o C)
removed before the 18ms short-circuit blanking timeout period, the next ramped current pulse soft
starts the output. FAULT remains high.
? If the short circuit persists after the fault-blanking period, FAULT goes low, autoreset mode
begins, and the output sources 25mA.
? If the output voltage rises above 0.5V for 20ms, the switch resets, the output turns on, and FAULT
goes high (see Short-Circuit Response in the Typical Operating Characteristics .)
? Output current regulates at I LIM and the blanking timer turns on. FAULT remains high during
the blanking timeout period.
? Continuous current at I LIM persists until either the 20ms blanking period expires or a thermal
fault occurs.
? If overcurrent persists after 20ms, FAULT goes low, autoreset mode is enabled, and the output
sources 25mA.
? If the output voltage rises above 0.5V for 20ms, the switch resets, the output turns on, and FAULT
goes high (see Short Overload Response in the Typical Operating Characteristics .)
? A junction temperature of +160°C immediately asserts FAULT low (the blanking timeout period
does not apply for thermal faults) and turns off the switch. When the junction cools by 15 ° C,
the thermal fault is cleared and FAULT goes high. Note that if other fault conditions are present
when a thermal fault clears, those fault states then take effect.
10
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相关代理商/技术参数 |
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| MAX1946EUA | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX1947ETA18 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX1947ETA18+ | 制造商:Maxim Integrated Products 功能描述:CONV DC-DC SGL-OUT STEP UP 8TDFN EP - Rail/Tube |
| MAX1947ETA18+T | 功能描述:直流/直流开关转换器 Step-Up w/RESET DC/DC Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX1947ETA18-T | 功能描述:直流/直流开关转换器 Step-Up w/RESET DC/DC Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
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