参数资料
型号: NCV51411DR2G
厂商: ON Semiconductor
文件页数: 7/16页
文件大小: 0K
描述: IC REG BUCK 1.5A 8SOIC
标准包装: 1
类型: 降压(降压)
输出数: 1
输入电压: 4.5 V ~ 40 V
PWM 型: 混合物
频率 - 开关: 260kHz
电流 - 输出: 1.5A
同步整流器:
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: 剪切带 (CT)
供应商设备封装: 8-SOICN
其它名称: NCV51411DR2GOSCT
NCV51411
IO(MAX) + ILIM * O
duty cycle of the sync pulses can vary from 10% to 90%. The
frequency foldback feature is disabled during the sync
mode.
Figure 4. A NCV51411 Buck Regulator is Synchronized
to an External 350 kHz Pulse Signal
Power Switch and Current Limit
The collector of the built ? in NPN power switch is
connected to the V IN pin, and the emitter to the V SW pin.
When the switch turns on, the V SW voltage is equal to the
V IN minus switch Saturation Voltage. In the buck regulator,
the V SW voltage swings to one diode drop below ground
when the power switch turns off, and the inductor current is
commutated to the catch diode. Due to the presence of high
pulsed current, the traces connecting the V SW pin, inductor
and diode should be kept as short as possible to minimize the
noise and radiation. For the same reason, the input capacitor
should be placed close to the V IN pin and the anode of the
diode.
The saturation voltage of the power switch is dependent
on the switching current, as shown in Figure 5.
0.7
0.6
0.5
0.4
0.3
0.2
0.1
The NCV51411 contains pulse ? by ? pulse current limiting
to protect the power switch and external components. When
the peak of the switching current reaches the Current Limit,
the power switch turns off after the Current Limit Delay. The
switch will not turn on until the next switching cycle. The
current limit threshold is independent of switching duty
cycle. The maximum load current, given by the following
formula under continuous conduction mode, is less than the
Current Limit due to the ripple current.
V (VIN * VO)
2(L)(VIN)(fs)
where:
f S = switching frequency,
I LIM = current limit threshold,
V O = output voltage,
V IN = input voltage,
L = inductor value.
When the regulator runs under current limit, the
subharmonic oscillation may cause low frequency
oscillation, as shown in Figure 6. Similar to current mode
control, this oscillation occurs at the duty cycle greater than
50% and can be alleviated by using a larger inductor value.
The current limit threshold is reduced to Foldback Current
when the FB pin falls below Foldback Threshold. This
feature protects the IC and external components under the
power up or over ? load conditions.
Figure 6. The Regulator in Current Limit
0
0
0.5 1.0
1.5
SWITCHING CURRENT (A)
Figure 5. The Saturation Voltage of the Power Switch
Increases with the Conducting Current
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NCV51411MNR2 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:1.5 A, 260 kHz, Low Voltage Buck Regulator with Synchronization Capability
NCV51411MNR2G 功能描述:直流/直流开关转换器 BUCK REGULATOR RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
NCV51411PWR2 功能描述:直流/直流开关转换器 1.5A Low Voltage RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
NCV51411PWR2G 功能描述:直流/直流开关转换器 1.5A Low Voltage Buck RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
NCV5171 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:1.5 A 280 kHz Boost Regulators