参数资料
| 型号： | NCP4330DR2G |
| 厂商： | ON Semiconductor |
| 文件页数： | 10/17页 |
| 文件大小： | 0K |
| 描述： | IC DRIVER POST REGULATION 8-SOIC |
| 标准包装： | 1 |
| 输出隔离： | 非隔离 |
| 频率范围： | 达 400kHz |
| 输入电压： | 5.2 V ~ 20 V |
| 输出电压： | 0.9 V ~ 23.5 V |
| 工作温度： | -40°C ~ 125°C |
| 封装/外壳： | 8-SOIC（0.154"，3.90mm 宽） |
| 供应商设备封装： | 8-SOICN |
| 包装： | 剪切带 (CT) |
| 其它名称： | NCP4330DR2GOSCT |
NCP4330
100
75
50
25
free wheeling operation continues (refer to application
schematic).
However, such a situation should occur only during transient
phases. Should this state occur too frequently, an excessive
heating of the Q2 switch could be produced.
70
60
50
40
0
0
0.5
1.0
1.5
2.0
2.5
30
I_ramp (mA)
Figure 25. High ? Side MOSFET Duty Cycle vs. I_ramp
Conditions: Switching Frequency: 400 kHz, Reset Pulse
20
10
Duration: 250 ns, Switching Delay (between LS and HS):
100 ns, Cramp = 100 pF.
0
0
0.1
0.2
0.3 0.4
0.5
0.6
One can note that the duty cycle increases when the
I_ramp current increases. The duty cycle is zero if the
I_ramp current is below about 110 μ A.
The duty cycle is limited to about 81% mainly by the reset
time and the 100 ns delay that all together represent 14% of
the period. In a 100 kHz application, the relative impact of
these times would be reduced and the maximum duty cycle
would be higher (in the range of 92%).
In fact, the high ? side on ? times are useful only during the
forward on ? times. Finally, if the duty cycle of the forward
converter is less than 80%, one can consider that the useful
post regulator duty cycle can vary between 0 and 100%.
It can also be noted that the HS MOSFET can be turned
on while the forward power switch is off, the forward
free ? wheeling MOSFET (Q2) is on and then no voltage is
applied to the post ? regulator. This is not an issue since the
MOSFETs Q2 and Q3 derive the L2 coil current so that the
I_ramp (mA)
Figure 26. HS MOSFET Duty Cycle vs. I_ramp (zoom)
RESET Block
The “reset” pin should receive the free ? wheeling drive
signal of the forward (refer to application schematic). When
this voltage exceeds the reset block threshold (2.55 V
typically), the C_ramp capacitor is grounded by an internal
switch for about 250 ns and the low ? side MOSFET is turned
on. The circuit is then initialized for a new cycle.
The voltage that is applied to the “reset” pin, may be
negative during one part of the period. The NCP4330
incorporates a negative clamp system to avoid that too
negative voltages on the pin may cause carriers injection
within the die. The negative clamp acts to force a minimum
voltage of about –0.3 V in conjunction with the external
resistor R3. It features a current capability of about 2.0 mA.
C
C_ramp
V DD
Negative
Clamp
RESET Pin
Voltage
1.55 V
Reset signal
R3
RST pin
V DD
2.55 V/
-
+
HYST COMP
250 ns
Vdelay
1
2
AND
Ctrl
3
Q?
NPN
Vdelay
Ctrl
GND
To HS and LS drivers
Figure 27. Reset Block
http://onsemi.com
10
250 ns
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相关代理商/技术参数 |
参数描述 |
|---|---|
| NCP4331 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Synchronous Buck Controller for High Efficiency Post Regulation |
| NCP4331DBR2G | 功能描述:IC REG CTRLR BUCK PWM 16-TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:100% 电源电压:8.2 V ~ 30 V 降压:无 升压:无 回扫:是 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:0°C ~ 70°C 封装/外壳:8-DIP（0.300"，7.62mm） 包装:管件 产品目录页面:1316 (CN2011-ZH PDF) |
| NCP4331DR2G | 功能描述:功率驱动器IC PWM CONTROLLER RoHS:否 制造商:Micrel 产品:MOSFET Gate Drivers 类型:Low Cost High or Low Side MOSFET Driver 上升时间: 下降时间: 电源电压-最大:30 V 电源电压-最小:2.75 V 电源电流: 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Tube |
| NCP433FCT2G | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:1.5A Ultra-Small Controlled Load Switch with Auto-Discharge Path |
| NCP434 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:2A Ultra-Small Controlled Load Switch with |
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