参数资料
| 型号： | NCP4302BDR2G |
| 厂商： | ON Semiconductor |
| 文件页数： | 12/16页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR FLYBK ISO PWM 8SOIC |
| 标准包装： | 1 |
| PWM 型： | 控制器 |
| 输出数： | 1 |
| 频率 - 最大： | 250kHz |
| 电源电压： | 9.2 V ~ 28 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： | -40°C ~ 125°C |
| 封装/外壳： | 8-SOIC（0.154"，3.90mm 宽） |
| 包装： | 剪切带 (CT) |
| 其它名称： | NCP4302BDR2GOSCT |
NCP4302
* 0.7 @ 1
I in +
V out @
Rth +
) R2
t on(delay) + 10 pF @
The minimum on time is set with a voltage divider with
resistors R2 and R3 (refer to Figure 27).
R3
R3 ) R2 Rth
Where Rth is the Thevenin equivalent resistance and is
calculated by:
1
1 1
R3
This input current is then used to charge an internal 10 pF
capacitor setting the minimum t on time.
4V
I in
V out
Adjustable t off Delay
The SYNC/CS input to the NCP4302 is used as the Set
input to the drive enable Flip Flop; refer to the internal block
diagram of the NCP4302. Refering to the SPICE
simulations (Figure 28), you can see that when the system is
operating under light load conditions the transformer
secondary voltage rings below ground when the current
reaches zero. When this occurs, the CS amplifier output may
be falsely triggered providing a Set input to the Drive Flip
Flop, turning on the output drive. To prevent the controller
from prematurely turning on the synchronous rectification
MOSFET, the output of the current sense amplifier is
connected to a logic block with a programmable off time
delay. The t off(delay) can be independently programmed
through the D LYADJ pin.
V out @
* 0.7 @
t off(delay) + 10 pF @
+
C out
R2
R3
R upper
R lower
I in +
R3
R3 ) R2
3.35 V
I in
1
100k
RS
DRV V CC
SYNC/CS
TRIG
GND
D LYADJ
V REF
CATH
I in
Figure 27. Typical Application
100 V
50 V
0V
? 50 V
100 m s
110 m s
120 m s
130 m s
140 m s
150 m s
160 m s
V(U1:4)
Time
Figure 28. Discontinuous Conduction Mode Drain Waveform
Trigger Input
The TRIG input is used to turn ? off the synchronous
MOSFET prior to its current reaching zero. This input is
required in a CCM operating mode. While there are several
ways to determine the TRIG input, the simplest way is to
generate a pulse in the primary side that precedes the turn ? on
of the primary MOSFET and transformer couple that pulse
to the secondary into the Trig input. In converters where the
TRIG input is not used. It is recommended to ground the
TRIG pin in these cases.
Voltage Amplifier and Reference
The NCP4302 incorporates an accurate TL431 type Shunt
regulator with two reference voltage options. The
NCP4302A has a 2.5 V reference and the NCP4302B has a
1.25 V reference.
operating mode is always designed to be DCM or QRM, the
http://onsemi.com
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相关代理商/技术参数 |
参数描述 |
|---|---|
| NCP4303A | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Secondary Side Synchronous Rectification Driver for High Efficiency SMPS Topologies |
| NCP4303ADR2G | 功能描述:初级与次级侧 PWM 控制器 SEC SIDE SYNC RECT DRV RoHS:否 制造商:ON Semiconductor 输出端数量:1 开关频率:250 KHz 工作电源电压:- 0.3 V to + 28 V 最大工作温度:+ 85 C 最小工作温度:- 5 C 封装 / 箱体:SOIC-8 Narrow 封装:Reel |
| NCP4303AMNTWG | 功能描述:IC CTLR/DVR SYNC RECT 8-DFN RoHS:是 类别:集成电路 (IC) >> PMIC - 电源控制器，监视器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- 应用:多相控制器 输入电压:- 电源电压:9 V ~ 14 V 电流 - 电源:- 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:40-WFQFN 裸露焊盘 供应商设备封装:40-TQFN-EP（5x5） 包装:带卷 (TR) |
| NCP4303B | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Secondary Side Synchronous Rectification Driver for High Efficiency SMPS Topologies |
| NCP4303BDR2G | 功能描述:初级与次级侧 PWM 控制器 SEC SIDE SYNC RECT DRV RoHS:否 制造商:ON Semiconductor 输出端数量:1 开关频率:250 KHz 工作电源电压:- 0.3 V to + 28 V 最大工作温度:+ 85 C 最小工作温度:- 5 C 封装 / 箱体:SOIC-8 Narrow 封装:Reel |
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