参数资料
| 型号： | MIC2285AYMT TR |
| 厂商： | Micrel Inc |
| 文件页数： | 11/14页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC ADJ 0.5A 10TMLF |
| 标准包装： | 1 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 可调至 1V |
| 输入电压： | 2.7 V ~ 5.5 V |
| 频率 - 开关： | 8MHz |
| 电流 - 输出： | 500mA |
| 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： | 10-UFDFN，10-TMLF? |
| 包装： | 标准包装 |
| 供应商设备封装： | 10-TMLF?（2x2） |
| 产品目录页面： | 1093 (CN2011-ZH PDF) |
| 其它名称： | 576-2123-6 576-2123-6-ND 576-2973-6 |
Micrel, Inc.
Applications Information
The MIC2285A is a 500mA PWM power supply that
utilizes a LOWQ light load mode to maximize battery
efficiency in light load conditions. This is achieved
with a LOWQ control pin that when pulled low, shuts
down all the biasing and drive current for the PWM
regulator, drawing only 18μA of operating current.
This allows the output to be regulated through the
LDO output, capable of providing 60mA of output
current. This method has the advantage of
producing a clean, low current, ultra-low noise
output in LOWQ mode. During LOWQ mode, the SW
node becomes high impedance, blocking current
flow. Other methods of reducing quiescent current,
such as pulse frequency modulation (PFM), or
bursting techniques, create large amplitude, low
frequency ripple voltages that can be detrimental to
system operation.
When more than 60mA is required, the LOWQ pin
can be forced high, causing the MIC2285A to enter
PWM mode. In this case, the LDO output makes a
"hand-off" to the PWM regulator with virtually no
variation in output voltage. The LDO output then
turns off allowing up to 600mA of current to be
efficiently supplied through the PWM output to the
load.
Input Capacitor
A minimum 1μF ceramic is recommended on the
VIN pin for bypassing. X5R or X7R dielectrics are
recommended for the input capacitor. Y5V
dielectrics lose most of their capacitance over
temperature and are therefore, not recommended.
MIC2285A
Output Capacitor
The MIC2285A is optimized for a 10μF output
capacitor. A larger value can be used to improve
transient response. The MIC2285A utilizes type III
internal compensation and utilizes an internal high
frequency zero to compensate for the double pole
roll off of the LC filter. For this reason, larger output
capacitors can create instabilities. X5R or X7R
dielectrics are recommended for the output
capacitor. Y5V dielectrics lose most of their
capacitance over temperature and are therefore, not
recommended.
In addition to a 10μF, a small 10nF is recommended
close to the load for high frequency filtering. Smaller
case size capacitors are recommended due to their
lower ESR and ESL.
Inductor Selection
The MIC2285A is designed for use with a 0.47μH
inductor. Proper selection should ensure that the
inductor can handle the maximum average and peak
currents required by the load. 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 that 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. Peak inductor current can be
calculated as follows:
V OUT ? ? 1 ? OUT
?
?
A minimum 1μF is recommended close to the VIN
and PGND pins for high frequency filtering. Smaller
case size capacitors are recommended due to their
lower ESR and ESL. Please refer to layout
I PK = I OUT
+
? V
? V IN
2 × f × L
?
?
recommendation section of data sheet for proper
layout of the input capacitor.
August 2007
11
M9999-083107-B
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MIC2285YML | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:8MHz PWM Synchronous Buck Regulator with LDO Standby Mode |
| MIC2285YML TR | 功能描述:直流/直流开关调节器 8MHz Synchronous Buck Regulator - low Q Mode (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 |
| MIC2285YML-TR | 功能描述:Buck Switching Regulator IC Positive Adjustable 1V 1 Output 500mA 10-VFDFN Exposed Pad, 10-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:可调式 输出数:1 电压 - 输入（最小值）:2.7V 电压 - 输入（最大值）:5.5V 电压 - 输出（最小值/固定）:1V 电压 - 输出（最大值）:5.5V 电流 - 输出:500mA 频率 - 开关:8MHz 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:10-VFDFN 裸露焊盘，10-MLF? 供应商器件封装:10-MLF?（3x3） 标准包装:1 |
| MIC2287 | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:1.2MHz PWM White LED Driver with OVP in 2mm 】 2mm MLF⑩ and Thin SOT-23 |
| MIC2287 6-LED EV | 制造商:Micrel Inc 功能描述:BOARD EVAL MIC2287 34V OVP |
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