- 您现在的位置：买卖IC网 > PDF目录19584 > MIC5255-3.5BM5 TR (Micrel Inc)IC REG LDO 3.5V .15A SOT23-5 PDF资料下载
参数资料
| 型号： | MIC5255-3.5BM5 TR |
| 厂商： | Micrel Inc |
| 文件页数： | 10/13页 |
| 文件大小： | 0K |
| 描述： | IC REG LDO 3.5V .15A SOT23-5 |
| 标准包装： | 3,000 |
| 稳压器拓扑结构： | 正，固定式 |
| 输出电压： | 3.5V |
| 输入电压： | 最高 6V |
| 电压 - 压降（标准）： | 0.135V @ 150mA |
| 稳压器数量： | 1 |
| 电流 - 输出： | 150mA |
| 电流 - 限制（最小）： | 160mA |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | SC-74A，SOT-753 |
| 供应商设备封装： | SOT-23-5 |
| 包装： | 带卷 (TR) |
| 其它名称： | MIC5255-3.5BM5TR MIC5255-3.5BM5TR-ND |
P D(max) = ? ?
? T J(max) ? T A ?
?
Micrel, Inc.
Application Information
Enable/Shutdown
The MIC5255 comes with an active-high enable pin that
allows the regulator to be disabled. Forcing the enable
pin low disables the regulator and sends it into a “zero”
off-mode-current state. In this state, current consumed
by the regulator goes nearly to zero. Forcing the enable
pin high enables the output voltage. This part is CMOS
and the enable pin cannot be left ? oating; a ? oating
enable pin may cause an indeterminate state on the
output.
Input Capacitor
The MIC5255 is a high performance, high bandwidth
device. Therefore, it requires a well-bypassed input
supply for optimal performance. A 1μF capacitor is
required from the input to ground to provide stability.
Low-ESR ceramic capacitors provide optimal
performance at a minimum of space. Additional high
frequency capacitors, such as small valued NPO
dielectric type capacitors, help ? lter out high frequency
noise and are good practice in any RF-based circuit.
Output Capacitor
The MIC5255 requires an output capacitor for stability.
The design requires 1μF or greater on the output to
maintain stability. The design is optimized for use with
low-ESR ceramic chip capacitors. High ESR capacitors
may cause high frequency oscillation. The maximum
recommended ESR is 300m ? . The output capacitor can
be increased, but performance has been optimized for a
1μF ceramic output capacitor and does not improve
MIC5255
large capacitor on the bypass pin without signi ? cantly
slowing turn-on time. Refer to the “ Typical Character-
istics ” section for performance with different bypass
capacitors.
Active Shutdown
The MIC5255 also features an active shutdown clamp,
which is an N-Channel MOSFET that turns on when the
device is disabled. This allows the output capacitor and
load to discharge, de-energizing the load.
No-Load Stability
The MIC5255 will remain stable and in regulation with no
load unlike many other voltage regulators. This is
especially important in CMOS RAM keep-alive
applications.
Thermal Considerations
The MIC5255 is designed to provide 150mA of
continuous current in a very small package. Maximum
power dissipation can be calculated based on the output
current and the voltage drop across the part. To
determine the maximum power dissipation of the
package, use the junction-to-ambient thermal resistance
of the device and the following basic equation:
?
? θ JA ?
T J(max) is the maximum junction temperature of the die,
125°C, and T A is the ambient operating temperature. θ JA
is layout dependent; Table 1 shows examples of
junction-to-ambient thermal resistance for the MIC5255.
signi ? cantly with larger capacitance.
X7R/X5R dielectric-type ceramic capacitors are recom-
mended because of their temperature performance.
X7R-type capacitors change capacitance by 15% over
their operating temperature range and are the most
Package
SOT23-5
(M5 or D5)
θ JA Recommended
Minimum Footprint
235°C/W
θ JA 1” Square
Copper Clad
185°C/W
θ JC
145°C/W
P D(max) = ?
? 125 ° C ? 50 ° C ?
stable type of ceramic capacitors. Z5U and Y5V
dielectric capacitors change value by as much as 50%
and 60%, respectively, over their operating temperature
ranges. To use a ceramic chip capacitor with Y5V
dielectric, the value must be much higher than an X7R
ceramic capacitor to ensure the same minimum
capacitance over the equivalent operating temperature
range.
Bypass Capacitor
A capacitor can be placed from the noise bypass pin to
ground to reduce output voltage noise. The capacitor
bypasses the internal reference. A 0.01μF capacitor is
recommended for applications that require low-noise
outputs. The bypass capacitor can be increased, further
reducing noise and improving PSRR. Turn-on time
increases slightly with respect to bypass capacitance. A
unique quick-start circuit allows the MIC5255 to drive a
Table 1. SOT-23-5 Thermal Resistance
The actual power dissipation of the regulator circuit can
be determined using the equation:
P D = (V IN – V OUT ) I OUT + V IN I GND
Substituting P D(max) for P D and solving for the operating
conditions that are critical to the application will give the
maximum operating conditions for the regulator circuit.
For example, when operating the MIC5255-3.0BM5 at
50°C with a minimum footprint layout, the maximum
input voltage for a set output current can be determined
as follows:
?
? 235 ° C/W ?
P D(max) = 315mW
November 2006
10
M9999-110906
相关PDF资料 |
PDF描述 |
|---|---|
| ECC05DRTH | CONN EDGECARD 10POS DIP .100 SLD |
| M5-320/192-6SAC | IC CPLD ISP 320MC 192IO 256SBGA |
| ASM30DRSH | CONN EDGECARD 60POS DIP .156 SLD |
| 172-015-283L001 | CONN DB15 FEMALE HI PROFILE NKL |
| GMM06DTMH-S189 | CONN EDGECARD 12POS R/A .156 SLD |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MIC5255-4.75BM5 TR | 功能描述:IC REG LDO 4.75V .15A SOT23-5 RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - 线性 系列:- 标准包装:500 系列:- 稳压器拓扑结构:正，固定式 输出电压:12V 输入电压:14.5 V ~ 35 V 电压 - 压降（标准）:- 稳压器数量:1 电流 - 输出:500mA 电流 - 限制（最小）:- 工作温度:-40°C ~ 125°C 安装类型:通孔 封装/外壳:TO-205AD，TO-39-3 金属罐 供应商设备封装:TO-39 包装:散装 其它名称:*LM78M12CH*LM78M12CH/NOPBLM78M12CH |
| MIC5256 | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:150mA UCap LDO with Error Flag |
| MIC5256_10 | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:150mA μCap LDO with Error Flag |
| MIC5256-1.5BM5 | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:150mA μCap LDO with Error Flag |
| MIC5256-1.5YM5 | 制造商:Rochester Electronics LLC 功能描述: 制造商:RF Micro Devices Inc 功能描述: |
发布紧急采购，3分钟左右您将得到回复。