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参数资料
| 型号： | MIC2174C-1YMM TR |
| 厂商： | Micrel Inc |
| 文件页数： | 15/27页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM 10-MSOP |
| 标准包装： | 2,500 |
| 系列： | Hyper Speed Control™ |
| PWM 型： | 混合物 |
| 输出数： | 1 |
| 频率 - 最大： | 338kHz |
| 占空比： | 87% |
| 电源电压： | 3 V ~ 40 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： | 带卷 (TR) |
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Micrel, Inc.
Making the assumption that the turn-on and turn-off
transition times are equal; the transition times can be
MIC2174/MIC2174C
The peak-to-peak inductor current ripple is:
t T =
V OUT × (V HSD(max) ? V OUT )
approximated by:
C ISS × V IN + C OSS × V HSD
I G
where:
C ISS and C OSS are measured at V DS = 0
I G = gate-drive current
(11)
Δ I L(pp) = (14)
V HSD(max) × f sw × L
The peak inductor current is equal to the average output
current plus one half of the peak-to-peak inductor current
ripple.
The total high-side MOSFET switching loss is:
I L(pk) =I OUT(max) + 0.5 × Δ I L(pp)
(15)
P AC = (V HSD + V D ) × I PK × t T × f SW
where:
t T = Switching transition time
(12)
The RMS inductor current is used to calculate the I 2 R
losses in the inductor.
I L(RMS) = I OUT(max) +
V D = Body diode drop (0.5V)
f SW = Switching Frequency (300kHz)
2
Δ I L(PP)
12
2
(16)
The high-side MOSFET switching losses increase with
the input voltage V HSD due to the longer turn-on time and
turn-off time. The low-side MOSFET switching losses
are negligible and can be ignored for these calculations.
Inductor Selection
Values for inductance, peak, and RMS currents are
required to select the output inductor. The input and
output voltages and the inductance value determine the
peak-to-peak inductor ripple current. Generally, higher
inductance values are used with higher input voltages.
Larger peak-to-peak ripple currents will increase the
power dissipation in the inductor and MOSFETs. Larger
output ripple currents will also require more output
capacitance to smooth out the larger ripple current.
Smaller peak-to-peak ripple currents require a larger
inductance value and therefore a larger and more
expensive inductor. A good compromise between size,
loss and cost is to set the inductor ripple current to be
equal to 20% of the maximum output current. The
inductance value is calculated by Equation 13:
Maximizing efficiency requires both the proper selection
of core material and the minimizing of winding
resistance. The high frequency operation of the
MIC2174/MIC2174C requires the use of ferrite materials
for all but the most cost sensitive applications.
Lower cost iron powder cores may be used but the
increase in core loss will reduce the efficiency of the
power supply. This is especially noticeable at low output
power. The winding resistance decreases efficiency at
the higher output current levels. The winding resistance
must be minimized although this usually comes at the
expense of a larger inductor. The power dissipated in the
inductor is equal to the sum of the core and copper
losses. At higher output loads, the core losses are
usually insignificant and can be ignored. At lower output
currents, the core losses can be a significant contributor.
Core loss information is usually available from the
magnetics vendor. Copper loss in the inductor is
calculated by Equation 17:
L =
where:
V OUT × (V HSD(max) ? V OUT )
V HSD(max) × f sw × 20% × I OUT(max)
(13)
P INDUCTOR(Cu) = I L(RMS)2 × R WINDING (17)
The resistance of the copper wire, R WINDING , increases
with the temperature. The value of the winding
resistance used should be at the operating temperature.
f SW = switching frequency, 300 kHz
20% = ratio of AC ripple current to DC output current
V HSD(max) = maximum power stage input voltage
P WINDING(Ht) = R WINDING(20°C) × (1 + 0.0042 × (T H – T 20°C ))
(18)
September 2010
15
M9999-091310-C
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MIC2176-1 | 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 |
| MIC2176-1YMM | 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 |
| MIC2176-1YMM 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 |
| MIC2176-2 | 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 |
| MIC2176-2YMM | 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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