- 您现在的位置：买卖IC网 > PDF目录14516 > MIC2230-S4YML TR (Micrel Inc)IC REG BUCK SYNC 0.8A DL 12MLF PDF资料下载
参数资料
| 型号： | MIC2230-S4YML TR |
| 厂商： | Micrel Inc |
| 文件页数： | 12/18页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC 0.8A DL 12MLF |
| 标准包装： | 1 |
| 类型： | 降压（降压） |
| 输出类型： | 固定 |
| 输出数： | 2 |
| 输出电压： | 1.2V，3.3V |
| 输入电压： | 2.5 V ~ 5.5 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 2.5MHz |
| 电流 - 输出： | 800mA |
| 同步整流器： | 是 |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 12-VFDFN 裸露焊盘，12-MLF? |
| 包装： | 标准包装 |
| 供应商设备封装： | 12-MLF?（4x4） |
| 产品目录页面： | 1092 (CN2011-ZH PDF) |
| 其它名称： | 576-3278-6 |
R2 =
? ?
? 1 ? ?
Micrel, Inc.
Applications Information
Input Capacitor
A minimum 2.2μF ceramic is recommended on the VIN
pin for bypassing. X5R or X7R dielectrics are
recommended for the input capacitor. Y5V dielectrics,
aside from losing most of their capacitance over
temperature, they also become resistive at high
frequencies. This reduces their ability to filter out high
frequency noise.
Output Capacitor
The MIC2230 was designed specifically for use with a
10μF or greater ceramic output capacitor. 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.
Inductor Selection
Inductor selection will be determined by the following
(not necessarily in the order of importance);
MIC2230
Feedback
The MIC2230 provides a feedback pin to adjust the
output voltage to the desired level. This pin connects
internally to an error amplifier. The error amplifier then
compares the voltage at the feedback to the internal
0.8V reference voltage and adjusts the output voltage to
maintain regulation. Calculating the resistor divider
network for the desired output is as follows;
R1
? V OUT ?
? V REF ?
Where V REF is 0.8V and V OUT is the desired output
voltage.
A 100k ? from the output to the feedback is
recommended for R1. Larger resistor values require an
additional capacitor (feed-forward) from the output to the
feedback. The large high-side resistor value and the
parasitic capacitance on the feedback pin (~10pF) can
cause an additional pole in the control loop. The
additional pole can create a phase loss at high
?
?
?
?
Inductance
Rated current value
Size requirements
DC resistance (DCR)
frequencies. This phase loss degrades transient
response by reducing phase margin. Adding feed-
forward capacitance negates the parasitic capacitive
effects of the feedback pin. Refer to Table 1 for
recommended feedforward capacitor values.
The MIC2230 was designed for use with a 2.2μH
Efficiency _% = ? ? OUT
? ? × 100
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 to 20% 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.
Compensation
The MIC2230 is an internally compensated, current
mode buck regulator. Current mode is achieved by
sampling the peak current and using the output of the
error amplifier to pulse width modulate the switch node
and maintain output voltage regulation.
The MIC2230 is designed to be stable with a 2.2μH
inductor with a 10μF ceramic (X5R) output capacitor.
Recommended C FF Total Feedback Resistance
22pF 1M - 2M ?
47pF 500k -1M ?
100pF 100k - 500k ?
180pF 10k - 100k ?
Table 1. Recommended Feed-forward Capacitor
Large feedback resistor values increase impedance,
making the feedback node more susceptible to noise
pick-up. A feed forward capacitor would also reduce
noise pick-up by providing a low impedance path to the
output. Refer to Table 1 for recommended feedforward
capacitor values.
Efficiency Considerations
Efficiency is defined as the amount of useful output
power, divided by the amount of power supplied.
? V × I OUT ?
? V IN × I IN ?
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 draw
April 2010
12
M9999-040810-C
相关PDF资料 |
PDF描述 |
|---|---|
| V375C3V3T75BF | CONVERTER MOD DC/DC 3.3V 75W |
| ESC26DRTN | CONN EDGECARD 52POS DIP .100 SLD |
| VI-B2R-EX-B1 | CONVERTER MOD DC/DC 7.5V 75W |
| V375C3V3T75BL3 | CONVERTER MOD DC/DC 3.3V 75W |
| PSU4765A | CAP ALUM 47UF 165V QC TERM |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MIC2230-SSYML | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:Dual Synchronous 800mA/800mA Step-Down DC/DC Regulator |
| MIC2230-SSYML TR | 功能描述:直流/直流开关调节器 High Efficiency Dual 800/800mA Buck Switcher with Fast Transient 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 |
| MIC2230-SSYML-TR | 功能描述:Buck Switching Regulator IC Positive Fixed 3.3V 2 Output 800mA 12-VFDFN Exposed Pad, 12-MLF? 制造商:microchip technology 系列:- 包装:剪切带（CT） 零件状态:有效 功能:降压 输出配置:正 拓扑:降压 输出类型:固定 输出数:2 电压 - 输入（最小值）:2.5V 电压 - 输入（最大值）:5.5V 电压 - 输出（最小值/固定）:3.3V 电压 - 输出（最大值）:- 电流 - 输出:800mA 频率 - 开关:2.5MHz 同步整流器:是 工作温度:-40°C ~ 125°C （TJ） 安装类型:表面贴装 封装/外壳:12-VFDFN 裸焊盘，12-MLF? 供应商器件封装:12-MLF?（4x4） 标准包装:1 |
| MIC2238 | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:Dual Synchronous 800mA/800mA Step-Down DC/DC Regulator |
| MIC2238_10 | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:2.5MHz Dual Phase PWM Buck Regulator |
发布紧急采购，3分钟左右您将得到回复。