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参数资料
| 型号： | MIC4682BM |
| 厂商： | Micrel Inc |
| 文件页数： | 11/15页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK 2A 8SOIC |
| 标准包装： | 95 |
| 系列： | SuperSwitcher™ |
| 类型： | 降压（降压） |
| 输出数： | 1 |
| 输入电压： | 4 V ~ 34 V |
| PWM 型： | 电压模式 |
| 频率 - 开关： | 200kHz |
| 电流 - 输出： | 2A |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 8-SOIC（0.154"，3.90mm 宽） |
| 包装： | 管件 |
| 供应商设备封装： | 8-SOIC |
Micrel, Inc.
Thermal Considerations
The MIC4682 SuperSwitcher? features the power-
SOIC-8.This package has a standard 8-pin small-outline
package profile, but with much higher power dissipation
than a standard SOIC-8. Micrel’s MIC4682 Super-
Switcher? family are the first DC-to-DC converters to
take full advantage of this package.
The reason that the power SOIC-8 has higher power
SOIC-8
JA
MIC4682
dissipation (lower thermal resistance) is that pins 2, 6, 7
and the die-attach paddle are a single piece of metal.
JC
CA
AM
BIE
NT
ground plane
heat sink area
The die is attached to the paddle with thermally
conductive adhesive. This provides a low thermal
resistance path from the junction of the die to the ground
pins. This design significantly improves package power
dissipation by allowing excellent heat transfer through
the ground leads to the printed circuit board.
One limitation of the maximum output current on any
MIC4682 design is the junction-to-ambient thermal
resistance ( θ JA ) of the design (package and ground
plane).
Examining θ JA in more detail:
printed circuit board
Figure 2. Power SOIC-8 Cross Section
Minimum Copper/Maximum Current Method Using
Figure 3, for a given input voltage range, determine the
minimum ground-plane heat-sink area required for the
application’s maximum continuous output current. Figure
3 assumes a constant die temperature of 75°C above
ambient.
where:
θ JA = ( θ JC + θ CA )
1.5
8V
12V
θ JC = junction-to-case thermal resistance
θ CA = case-to-ambient thermal resistance
θ JC is a relatively constant 20°C/W for a power SOIC-8.
θ CA is dependent on layout and is primarily governed by
1.0
0.5
24V
V IN = 30V
the connection of pins 2, 6 and 7 to the ground plane.
The purpose of the ground plane is to function as a heat
T A = 50°C
sink.
θ JA is ideally 63°C/W, but will vary depending on the size
0
0
5
10 15
AREA (cm 2 )
20
25
of the ground plane to which the power SOIC-8 is
attached.
Determining Ground-Plane Heat-Sink Area
There are two methods of determining the minimum
ground plane area required by the MIC4682.
Quick Method
Make sure that MIC4682 pins 2, 6 and 7 are connected
to a ground plane with a minimum area of 6cm 2 . This
ground plane should be as close to the MIC4682 as
possible. The area may be distributed in any shape
around the package or on any PCB layer as long as
there is good thermal contact to pins 2, 6 and 7. This
ground plane area is more than sufficient for most
designs.
Figure 3. Output Current vs. Ground Plane Area
When designing with the MIC4682, it is a good practice
to connect pins 2, 6 and 7 to the largest ground plane
that is practical for the specific design.
Checking the Maximum Junction Temperature
For this example, with an output power (P OUT ) of 5W, (5V
output at 1A maximum with V IN = 12V) and 65°C
maximum ambient temperature, what is the maximum
junction temperature?
Referring to the “Typical Characteristics: Efficiency vs.
Output Current” graph, read the efficiency ( η ) for 1A
output current at V IN = 12V or perform you own
measurement.
η = 81%
The efficiency is used to determine how much of the
output power (P OUT ) is dissipated in the regulator circuit
(P D ).
June 2007
11
M9999-061507
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MIC4682BM TR | 功能描述:IC REG BUCK 2A 8SOIC RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:SuperSwitcher™ 标准包装:20 系列:SIMPLE SWITCHER® 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:12V 输入电压:4 V ~ 60 V PWM 型:电压模式 频率 - 开关:52kHz 电流 - 输出:1A 同步整流器:无 工作温度:-40°C ~ 125°C 安装类型:通孔 封装/外壳:16-DIP（0.300"，7.62mm） 包装:管件 供应商设备封装:16-DIP 其它名称:*LM2575HVN-12LM2575HVN-12 |
| MIC4682YM | 功能描述:直流/直流开关调节器 Precision Current Limit SO-8 Super Switcher (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 |
| MIC4682YM TR | 功能描述:直流/直流开关调节器 Precision Current Limit SO-8 Super Switcher (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 |
| MIC4684 | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:2A High-Efficiency SuperSwitcher Buck Regulator |
| MIC4684_10 | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:2A High-Efficiency SuperSwitcher Buck Regulator |
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