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参数资料
| 型号： | MIC2176-2YMM |
| 厂商： | Micrel Inc |
| 文件页数： | 17/31页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM 10-MSOP |
| 标准包装： | 100 |
| 系列： | Hyper Speed Control™ |
| PWM 型： | 混合物 |
| 输出数： | 1 |
| 频率 - 最大： | 250kHz |
| 占空比： | 93% |
| 电源电压： | 4.5 V ~ 75 V |
| 降压： | 是 |
| 升压： | 无 |
| 回扫： | 无 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | -40°C ~ 125°C |
| 封装/外壳： | 10-TFSOP，10-MSOP（0.118"，3.00mm 宽） |
| 包装： | 管件 |
| 其它名称： | 576-3757-5 |
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Micrel, Inc.
Application Information
MOSFET Selection
The MIC2176 controller works from power stage input
MIC2176
accurately calculated using C ISS at V DS = 0 instead of
gate charge.
For the low-side MOSFET:
voltages of 4.5V to 73V and has an external 4.5V to 5.5V
V IN to provide power to turn the external N-Channel
power MOSFETs for the high- and low-side switches.
I G[low - side] (avg) = C ISS × V GS × f SW
(7)
For applications where V DD < 5V, it is necessary that the
power MOSFETs used are sub-logic level and are in full
conduction mode for V GS of 2.5V. For applications when
V DD > 5V; logic-level MOSFETs, whose operation is
specified at V GS = 4.5V must be used.
There are different criteria for choosing the high-side and
low-side MOSFETs. These differences are more
significant at lower duty cycles. In such an application,
the high-side MOSFET is required to switch as quickly
as possible to minimize transition losses, whereas the
low-side MOSFET can switch slower, but must handle
larger RMS currents. When the duty cycle approaches
50%, the current carrying capability of the high-side
MOSFET starts to become critical.
It is important to note that the on-resistance of a
MOSFET increases with increasing temperature. A 75°C
rise in junction temperature will increase the channel
resistance of the MOSFET by 50% to 75% of the
resistance specified at 25°C. This change in resistance
Since the current from the gate drive comes from the
V DD , the power dissipated in the MIC2176 due to gate
drive is:
P GATEDRIVE = V DD × (I G[high- side] (avg) + I G[low - side] (avg)) (8)
A convenient figure of merit for switching MOSFETs is
the on resistance times the total gate charge R DS(ON) ×
Q G . Lower numbers translate into higher efficiency. Low
gate-charge logic-level MOSFETs are a good choice for
use with the MIC2176. Also, the R DS(ON) of the low-side
MOSFET will determine the current-limit value. Please
refer to “Current Limit” subsection is Functional
Description for more details.
Parameters that are important to MOSFET switch
selection are:
? Voltage rating
must be accounted for when calculating MOSFET power
dissipation and in calculating the value of current limit.
Total gate charge is the charge required to turn the
?
?
On-resistance
Total gate charge
MOSFET on and off under specified operating conditions
(V DS and V GS ). The gate charge is supplied by the
MIC2176 gate-drive circuit. At 300kHz switching
frequency, the gate charge can be a significant source of
power dissipation in the MIC2176. At low output load,
this power dissipation is noticeable as a reduction in
efficiency. The average current required to drive the
high-side MOSFET is:
The voltage ratings for the high-side and low-side
MOSFETs are essentially equal to the power stage input
voltage V HSD . A safety factor of 20% should be added to
the V DS (max) of the MOSFETs to account for voltage
spikes due to circuit parasitic elements.
The power dissipated in the MOSFETs is the sum of the
conduction losses during the on-time (P CONDUCTION ) and
the switching losses during the period of time when the
I G[high - side] (avg) = Q G × f SW
(6)
MOSFETs turn on and off (P AC ).
where:
I G[high-side] (avg) = Average high-side MOSFET gate
current
Q G = Total gate charge for the high-side MOSFET taken
from the manufacturer’s data sheet for V GS = V DD .
f SW = Switching Frequency
The low-side MOSFET is turned on and off at V DS = 0
because an internal body diode or external freewheeling
diode is conducting during this time. The switching loss
for the low-side MOSFET is usually negligible. Also, the
gate-drive current for the low-side MOSFET is more
P SW = P CONDUCTION + P AC
P CONDUCTION = I SW(RMS) 2 × R DS(ON)
P AC = P AC(off ) + P AC(on)
where:
R DS(ON) = On-resistance of the MOSFET switch
D = Duty Cycle = V OUT / V HSD
(9)
(10)
(11)
November 2010
17
M9999-111710-A
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相关代理商/技术参数 |
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|---|---|
| MIC2176-2YMM 5A EV | 功能描述:电源管理IC开发工具 76V Synchronous Buck Controller - Evaluation Board RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
| MIC2176-2YMM TR | 功能描述:DC/DC 开关控制器 76V Synchronous Buck Controller RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| MIC2176-3 | 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:Wide Input Voltage, Synchronous Buck Controllers Featuring Adaptive On-Time Control |
| MIC2176-3YMM | 功能描述:DC/DC 开关控制器 76V Synchronous Buck Controller RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| MIC2176-3YMM TR | 功能描述:DC/DC 开关控制器 76V Synchronous Buck Controller RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
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