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參數(shù)資料
| 型號： | MIC37501-1.5BR |
| 廠商： | MICREL INC |
| 元件分類： | 固定正電壓單路輸出LDO穩(wěn)壓器 |
| 英文描述： | 5A, Low voltage uCap LDO REgulator |
| 中文描述： | 1.5 V FIXED POSITIVE LDO REGULATOR, 0.35 V DROPOUT, PSSO7 |
| 封裝： | SPAK-7 |
| 文件頁數(shù)： | 10/11頁 |
| 文件大?。?/td> | 386K |
| 代理商： | MIC37501-1.5BR |
Micrel, Inc.
MIC37501/37502
February 2007
8
M9999-020507
Application Information
The MIC37501/02 is a high-performance, low dropout
voltage regulator suitable for moderate to high-current
regulator applications. Its 500mV dropout voltage at
full load makes it especially valuable in battery-
powered systems and as a high-efficiency noise filter
in post-regulator applications. Unlike older NPN-pass
transistor designs, where the minimum dropout
voltage is limited by the based-to-emitter voltage drop
and collector-to-emitter saturation voltage, dropout
performance of the PNP output of these devices is
limited only by the low VCE saturation voltage.
A trade-off for the low dropout voltage is a varying
base drive requirement. Micrel’s Super βeta PNP
process reduces this drive requirement to only 2% to
5% of the load current.
The MIC37501/02 regulator is fully protected from
damage due to fault conditions. Current limiting is
provided. This limiting is linear; output current during
overload conditions is constant. Thermal shutdown
disables the device when the die temperature
exceeds the maximum safe operating temperature.
The output structure of these regulators allows
voltages in excess of the desired output voltage to be
applied without reverse current flow.
Thermal Design
Linear regulators are simple to use. The most
complicated design parameters to consider are
thermal characteristics. Thermal design requires the
following application-specific parameters:
Maximum ambient temperature (TA)
Output current (IOUT)
Output voltage (VOUT)
Input voltage (VIN)
Ground current (IGND)
First, calculate the power dissipation of the regulator
from these numbers and the device parameters from
this data sheet.
PD = (VIN – VOUT) IOUT + VIN IGND
where the ground current is approximated by using
numbers from the “Electrical Characteristics” or
“Typical Characteristics” sections. The heat sink
thermal resistance is then determined with this
formula:
θSA = ((TJ(max) – TA)/ PD) – (θJC + θCS)
Where TJ(max) ≤125°C and θCS is between 0°C and
2°C/W. The heat sink may be significantly reduced in
applications where the minimum input voltage is
known and is large compared with the dropout
voltage. Use a series input resistor to drop excessive
voltage and distribute the heat between this resistor
and the regulator. The low dropout properties of Micrel
Super
βeta
PNP
regulators
allow
significant
reductions in regulator power dissipation and the
associated
heat
sink
without
compromising
performance. When this technique is employed, a
capacitor of at least 1.0F is needed directly between
the input and regulator ground.
Refer to “Application Note 9” for further details and
examples
on
thermal
design
and
heat
sink
applications.
Output Capacitor
The MIC37501/02 requires an output capacitor for
stable operation. As a Cap LDO, the MIC37501/02
can operate with ceramic output capacitors as long as
the amount of capacitance is 100F or greater. For
values of output capacitance lower than 100F, the
recommended ESR range is 200m to 2. The
minimum value of output capacitance recommended
for the MIC37501/02 is 47F.
For 100F or greater, the ESR range recommended is
less than 1. Ultra-low ESR ceramic capacitors are
recommended for output capacitance of 100F or
greater to help improve transient response and noise
reduction at high frequency. X7R/X5R dielectric-type
ceramic capacitors are recommended because of
their temperature performance. X7Rtype capacitors
change capacitance by 15% over their operating
temperature range and are the most 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.
Input Capacitor
An input capacitor of 1.0F or greater is recom-
mended when the device is more than 4 inches away
from the bulk supply capacitance, or when the supply
is a battery. Small, surfacemount chip capacitors can
be used for the bypassing. The capacitor should be
placed within 1" of the device for optimal performance.
Larger values will help to improve ripple rejection by
bypassing the input to the regulator, further improving
the integrity of the output voltage.
Transient Response and 3.3V to 2.5V, 2.5V to 1.8V
or 1.65V, or 2.5V to 1.5V Conversions
The MIC37501/02 has excellent transient response to
variations in input voltage and load current. The
device has been designed to respond quickly to load
current variations and input voltage variations. Large
output capacitors are not required to obtain this
performance. A standard 47F output capacitor is all
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相關(guān)代理商/技術(shù)參數(shù) |
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| MIC37501-2.5BR | 功能描述:IC REG LDO 2.5V SPAK-7 RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 標準包裝:3,000 系列:- 穩(wěn)壓器拓撲結(jié)構(gòu):正，固定式 輸出電壓:3.8V 輸入電壓:最高 16V 電壓 - 壓降（標準）:0.3V @ 80mA 穩(wěn)壓器數(shù)量:1 電流 - 輸出:80mA 電流 - 限制（最小）:- 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:SC-74A，SOT-753 供應(yīng)商設(shè)備封裝:SOT-23-5 包裝:帶卷 (TR) 其它名稱:MIC5203-3.8BM5TRMIC5203-3.8BM5TR-ND |
| MIC37501-2.5BR TR | 功能描述:IC REG LDO 2.5V SPAK-7 RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 標準包裝:3,000 系列:- 穩(wěn)壓器拓撲結(jié)構(gòu):正，固定式 輸出電壓:3.8V 輸入電壓:最高 16V 電壓 - 壓降（標準）:0.3V @ 80mA 穩(wěn)壓器數(shù)量:1 電流 - 輸出:80mA 電流 - 限制（最?。?- 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:SC-74A，SOT-753 供應(yīng)商設(shè)備封裝:SOT-23-5 包裝:帶卷 (TR) 其它名稱:MIC5203-3.8BM5TRMIC5203-3.8BM5TR-ND |
| MIC37501-2.5WR | 功能描述:低壓差穩(wěn)壓器 - LDO 5A Low Voltage LDO Regulator(ROHS Compliant) RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動電壓（最大值）:307 mV 輸出電流:1 A 負載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20 |
| MIC37501-2.5WR TR | 功能描述:低壓差穩(wěn)壓器 - LDO 5A Low Voltage LDO Regulator(ROHS Compliant) RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動電壓（最大值）:307 mV 輸出電流:1 A 負載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20 |
| MIC37501-3.3BR | 功能描述:IC REG LDO 3.3V SPAK-7 RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 標準包裝:3,000 系列:- 穩(wěn)壓器拓撲結(jié)構(gòu):正，固定式 輸出電壓:3.8V 輸入電壓:最高 16V 電壓 - 壓降（標準）:0.3V @ 80mA 穩(wěn)壓器數(shù)量:1 電流 - 輸出:80mA 電流 - 限制（最?。?- 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:SC-74A，SOT-753 供應(yīng)商設(shè)備封裝:SOT-23-5 包裝:帶卷 (TR) 其它名稱:MIC5203-3.8BM5TRMIC5203-3.8BM5TR-ND |
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