参数资料
| 型号： | MIC2203BMM TR |
| 厂商： | Micrel Inc |
| 文件页数： | 7/13页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK ADJ 0.3A 10MSOP |
| 标准包装： | 2,500 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 可调至 0.5V |
| 输入电压： | 2.3 V ~ 5.5 V |
| PWM 型： | 电压模式 |
| 频率 - 开关： | 1MHz |
| 电流 - 输出： | 300mA |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 10-TFSOP，10-MSOP（0.118"，3.00mm 宽） |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 10-MSOP |
| 其它名称： | MIC2203BMMTR MIC2203BMMTR-ND |
Micrel, Inc.
Application Information
Input Capacitor
A minimum 1 μ F ceramic capacitor is recommended
on the V IN pin for bypassing. X5R or X7R dielectrics
are recommended for the input capacitor. Y5V
MIC2203
Bias Capacitor
A small 10nF ceramic capacitor is required to
bypass the bias pin. The use of low ESR ceramics
provides improved filtering for the bias supply.
Efficiency Considerations
dielectrics,
aside
from
losing
most
of their
Efficiency is defined as the amount of useful output
? V × I OUT ?
? V IN × I IN ?
capacitance over temperature, also become resis-
tive at high frequencies. This reduces their ability to
filter out high frequency noise.
Output Capacitor
The MIC2203 was designed specifically for the use
of a 2.2 μ F ceramic output capacitor. Since the
MIC2203 is voltage mode regulator, the control loop
relies on the inductor and output capacitor for
compensation. For this reason, do not use
excessively large output capacitors. The output
capacitor requires either an X7R or X5R dielectric.
Y5V and Z5U dielectric capacitors, aside from the
undesirable effect of their wide variation in
capacitance over temperature, become resistive at
high frequencies. Using Y5V or Z5U capacitors will
cause instability in the MIC2203.
Total output capacitance should not exceed 3 μ F.
Inductor Selection
Inductor selection will be determined by the following
(not necessarily in the order of importance):
? Inductance
? Rated current value
? Size requirements
? DC resistance (DCR)
The MIC2203 is designed for use with a 10 μ H
inductor.
Maximum current ratings of the inductor are
generally given in two methods: permissible DC
current and saturation current. Permissible DC
current can be rated either for a 40°C temperature
rise or a 10% loss in inductance. Ensure the inductor
selected can handle the maximum operating current.
When saturation current is specified, make sure that
there is enough margin that the peak current will not
saturate the inductor.
The size requirements refer to the area and height
requirements that are necessary to fit a particular
design. Please refer to the inductor dimensions on
their datasheet.
DC resistance is also important. While DCR is
inversely proportional to size, DCR can represent a
significant efficiency loss. Refer to the “Efficiency
Considerations” below for a more detailed
description.
power, divided by the amount of power consumed.
Efficiency% = ? OUT ? × 100
Maintaining high efficiency serves two purposes. It
reduces power dissipation in the power supply,
reducing the need for heat sinks and thermal design
considerations, and it reduces consumption of
current for battery powered applications. Reduced
current drawn from a battery increases the device’s
operating time, which is critical in hand held devices.
There are two loss terms in switching converters: DC
losses and switching losses. DC losses are simply
2
the power dissipation of I R. Power is dissipated in
the high side switch during the on cycle. Power loss
is equal to the high side MOSFET R DS(ON) multiplied
2
by the (Switch Current) . During the off cycle, the
low side N-Channel MOSFET conducts, also
dissipating power. Device operating current also
reduces efficiency. The product of the quiescent
(operating) current and the supply voltage is another
DC loss. The current required to drive the gates on
and off at a constant 1MHz frequency and the
switching transitions make up the switching losses.
Figure 2 shows an efficiency curve. The non-shaded
portion, from 0mA to 100mA, efficiency losses are
dominated by quiescent current losses, gate drive
and transition losses. In this case, lower supply
voltages yield greater efficiency in that they require
less current to drive the MOSFETs and have
reduced input power consumption.
Figure 2. Efficiency Curve
The shaded region, 100mA to 300mA, efficiency
loss is dominated by MOSFET R DS(ON) and inductor
DC losses. Higher input supply voltages will increase
December 2004
7
M9999-120604
(408) 955-1690
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MIC2203YML | 制造商:Rochester Electronics LLC 功能描述: 制造商:RF Micro Devices Inc 功能描述: |
| MIC2203YML TR | 功能描述:直流/直流开关调节器 1MHz Synchronous Buck Regulator 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 |
| MIC2203YMM | 功能描述:直流/直流开关调节器 1MHz Synchronous Buck Regulator 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 |
| MIC2203YMM TR | 功能描述:直流/直流开关调节器 1MHz Synchronous Buck Regulator 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 |
| MIC2204 | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:High-Efficiency 2MHz Synchronous Buck Converter |
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