参数资料
| 型号： | MIC4043BM4 TR |
| 厂商： | Micrel Inc |
| 文件页数： | 6/12页 |
| 文件大小： | 0K |
| 描述： | IC REG SHUNT LOW VOLT SOT-143 |
| 标准包装： | 3,000 |
| 应用： | 转换器，电源 |
| 输入电压： | 10V |
| 输出数： | 1 |
| 输出电压： | 10V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | TO-253-4，TO-253AA |
| 供应商设备封装： | SOT-143 |
| 包装： | 带卷 (TR) |
| 其它名称： | MIC4043BM4TR MIC4043BM4TR-ND |
MIC4043
Applications Information
Replacement of ’ 431-Type Devices
Since the MIC4043 uses a high-side reference, external
voltage dividers providing the feedback voltage will be
inverted when compared to those used with ’431-equiva-
Micrel
response, if a network analyzer is not available, is to step load
the output of the systems from 10% to 100% of nominal load.
The resultant small signal response at the output of the
systems will provide an idea of which direction to go based on
the overshoot and settling time of V OUT .
V TRIP = 1.245V ?
+ 1 ?
MIC4043
lent devices.
The industry-standard ’ 431 is also typically used in series with
an opto-isolator LED. This configuration has a voltage drop of
at least 2.5V for the ’ 431 plus 1.4V for the LED (3.9V). More
recent lower-voltage shunt regulators require at least 1.25V
Voltage Detector
V OUT
(FROM
POWER
SUPPLY)
R1 R PULL-UP
? R2 ?
? R1 ?
of headroom in addition to the 1.4V for the opto isolator, for
a total of 2.65V.
The MIC4043 removes the need to place the shunt reference
IN SNK
GND FB
R2
33k
Logic
Output
DISABLED
ENABLED
in parallel with the opto-isolator. The MIC4043 combines a
1.245V reference in conjunction with an error amplifier that
drives an NPN output transistor. The NPN transistor is
connected in series with the opto-isolator and regulates the
drive current in the opto-isolator. Unlike conventional shunt
regulators, the MIC4043 does not have to connect the shunt
Figure 1. Voltage Detector
Figure 1 shows a simple voltage threshold detector with a
logic output.
High-Current Regulator
reference in series with the opto-isolator. Only the NPN
output stage is in series with the opto-isolator, so the voltage
V IN
V OUT = 2.5V
V OUT = 1.245V ?
+ 1 ?
drop is just the saturation voltage or one transistor, typucally
160mV at full load
Compensation
I BIAS
≥ 500 μ A
R BIAS
MIC4043
Q1
∴ R1 = 33k, R2 = 33k
? R2 ?
? R1 ?
The noninverting side of the error amplifier is connected to the
IN SNK
high-side reference; the reference is connected to the IN pin.
The inverting side of the error amplifier is brought out to the
GND FB
R2
33k
FB pin. For some applications, no compensation is needed,
but for most, some resistor capacitor network is necessary
40 ?
1000pF
between the FB pin and GND pin. The value of the feedback
capacitance is application specific, but for most applications
100pF to 3000pF is all that is needed. Changing the feedback
capacitor changes the loop response; that is, phase and gain
margin. An empirical way to check overall system loop
Figure 2. High-Current Regulator
For the high-current regulator shown in Figure 2, headroom
is equal to the saturation voltage of Q1 plus the saturation
voltage of the MIC4043 (V SAT(min) = 200mV).
MIC4043
6
November 2000
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相关代理商/技术参数 |
参数描述 |
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| MIC4043YM4 | 制造商:MIC 制造商全称:MIC GROUP RECTIFIERS 功能描述:Low-Voltage Secondary-Side Shunt Regulator Final Information |
| MIC4043YM4 TR | 功能描述:直流/直流开关调节器 Low-voltage secondary-side shunt regulator (Lead Free) RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| MIC4043YM4-TR | 功能描述:- Converter, Power Supplies Voltage Regulator IC 1 Output SOT-143 制造商:microchip technology 系列:- 包装:* 零件状态:停产 应用:转换器，电源 电压 - 输入:10V 输出数:1 电压 - 输出:10V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:TO-253-4，TO-253AA 供应商器件封装:SOT-143 标准包装:1 |
| MIC4100 | 制造商:MIC 制造商全称:MIC GROUP RECTIFIERS 功能描述:100V Half Bridge MOSFET Drivers |
| MIC4100_11 | 制造商:MIC 制造商全称:MIC GROUP RECTIFIERS 功能描述:100V Half Bridge MOSFET Drivers |
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