- 您现在的位置：买卖IC网 > PDF目录19567 > MIC5271-5.0BM5 TR (Micrel Inc)IC REG LDO -5V .1A SOT23-5 PDF资料下载
参数资料
| 型号： | MIC5271-5.0BM5 TR |
| 厂商： | Micrel Inc |
| 文件页数： | 8/10页 |
| 文件大小： | 0K |
| 描述： | IC REG LDO -5V .1A SOT23-5 |
| 标准包装： | 3,000 |
| 稳压器拓扑结构： | 负，固定式 |
| 输出电压： | -5V |
| 输入电压： | 可下调至-16V |
| 电压 - 压降（标准）： | 0.5V @ 100mA |
| 稳压器数量： | 1 |
| 电流 - 输出： | 100mA |
| 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： | MIC5271-5.0BM5TR MIC5271-5.0BM5TR-ND |
MIC5271
Applications Information
The MIC5271 is a general-purpose negative regulator that
can be used in any system that requires a clean negative
voltage from a negative output. This includes post regulating
of DC-DC converters (transformer based or charge pump
based voltage converters). These negative voltages typically
require a negative low dropout voltage regulator to provide a
clean output from typically noisy lines.
Input Capacitor
A 1 μ F input capacitor should be placed from IN to GND if
there is more than 2 inches of wire or trace between the input
and the AC filter capacitor, or if a battery is used as the input.
Output Capacitor
The MIC5271 requires an output capacitor for stable opera-
tion. A minimum of 1 μ F of output capacitance is required. The
output capacitor can be increased without limitation to im-
prove transient response. The output does not require ESR
to maintain stability, therefore a ceramic capacitor can be
used. High-ESR capacitors may cause instability. Capacitors
with an ESR of 3 ? or greater at 100kHz may cause a high
frequency oscillation.
Micrel
Thermal Considerations
Absolute values will be used for thermal calculations to clarify
the meaning of power dissipation and voltage drops across
the part.
Proper thermal design for the MIC5271-5.0BM5 can be
accomplished with some basic design criteria and some
simple equations. The following information must be known
to implement your regulator design:
V IN = input voltage
V OUT = output voltage
I OUT = output current
T A = ambient operating temperature
I GND = ground current
Maximum power dissipation can be determined by knowing
the ambient temperature, T A , the maximum junction tem-
perature, 125 ° C, and the thermal resistance, junction to
ambient. The thermal resistance for this part, assuming a
minimum footprint board layout, is 235 ° C/W. The maximum
power dissipation at an ambient temperature of 25 ° C can be
determined with the following equation:
Low-ESR tantalums are recommended due to the tight ca-
pacitance tolerance over temperature.
Ceramic chip capacitors have a much greater dependence
on temperature, depending upon the dielectric. The X7R is
recommended for ceramic capacitors because the dielectric
will change capacitance value by approximately 15% over
P D(max) =
P D(max) =
T J(max) ? T A
θ JA
125 ° C ? 25 ° C
235 ° C/W
425mW = ( V IN ) IN × 1mA
425mW = ( 100mA × V IN IN ) ? 500mW
temperature. The Z5U dielectric can change capacitance
value by as much 50% over temperature, and the Y5V
dielectric can change capacitance value by as much as 60%
over temperature. To use a ceramic chip capacitor with the
Y5V dielectric, the value must be much higher than a tanta-
lum to ensure the same minimum capacitor value over
temperature.
No-Load Stability
The MIC5271 does not require a load for stability.
Enable Input
The MIC5271 comes with an enable pin that allows the
regulator to be disabled. Forcing the enable pin higher than
the negative threshold and lower than the positive threshold
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. The MIC5271 will be in the on mode when
the voltage applied to the enable pin is either greater than the
positive threshold or less than the negative threshold.
Enable Input
5
4
P D(max) = 425mW
The actual power dissipation of the regulator circuit can be
determined using one simple equation.
P D = ( V IN – V OUT ) I OUT + V IN × I GND
Substituting P D(max) , determined above, 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. The maximum power dissipation number cannot be
exceeded for proper operation of the device. The maximum
input voltage can be determined using the output voltage of
5.0V and an output current of 100mA. Ground current, of 1mA
for 100mA of output current, can be taken from the “ Electrical
Characteristics ” section of the data sheet.
? 5.0V 100mA + V
+ 1mA × V
925mW = 101mA × V IN
V IN = 9.16Vmax
MIC5271
3
2
1
0
-1
-2
-3
-4
-5
-3
Regulator On
Regulator Off
Regulator On
-5 -7 -9 -11 -13 -15
SUPPLY VOLTAGE (V)
8
Therefore, a –5.0V application at 100mA of output current
can accept a maximum input voltage of –9.16V in a SOT-23-5
package. For a full discussion of heat sinking and thermal
effects on voltage regulators, refer to Regulator Thermals
section of Micrel’s “Designing with Low Dropout Voltage
Regulators” handbook.
October 2003
相关PDF资料 |
PDF描述 |
|---|---|
| XC95108-10TQ100I | IC CPLD 108 MCELL I-TEMP 100TQFP |
| VI-B4H-CY-F2 | CONVERTER MOD DC/DC 52V 50W |
| ACC30DRXI-S734 | CONN EDGECARD 60POS DIP .100 SLD |
| 5M160ZT100C4N | IC MAX V CPLD 160 LE 100-TQFP |
| XC95108-15PQ160I | IC CPLD 108 MCELL I-TEMP 160PQFP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MIC5271BM5 | 制造商:Rochester Electronics LLC 功能描述: 制造商:RF Micro Devices Inc 功能描述: |
| MIC5271BM5 TR | 功能描述:IC REG LDO NEG ADJ .1A 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 |
| MIC5271BM5TR | 制造商:Rochester Electronics LLC 功能描述:- Tape and Reel |
| MIC5271YM5 TR | 功能描述:低压差稳压器 - LDO 100mA Negative uCap LDO Regulator with Enable(Lead Free) RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压（最大值）:307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20 |
| MIC5271YM5TR | 制造商:Micrel 功能描述:LDO Regulator Neg -1.2V to -14V 0.1A |
发布紧急采购，3分钟左右您将得到回复。