参数资料
| 型号： | NCP1252CDR2G |
| 厂商： | ON Semiconductor |
| 文件页数： | 13/18页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR FLYBK ISO PWM 8SOIC |
| 标准包装： | 1 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 550kHz |
| 占空比： | 69% |
| 电源电压： | 9 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： | -25°C ~ 125°C |
| 封装/外壳： | 8-SOIC（0.154"，3.90mm 宽） |
| 包装： | 标准包装 |
| 其它名称： | NCP1252CDR2GOSDKR |
NCP1252
The following figure illustrates a soft start sequence.
Soft Start pin
T SS = 13 ms
(2 V/div)
V SS = 4 V
CS pin
(0.5 V/div)
Time
(4 ms/div)
Figure 33. Soft Start Example
Brown ? Out Protection
By monitoring the level on BO pin, the controller protects
the forward converter against low input voltage conditions.
When the BO pin level falls below the V BO level, the
controllers stops pulsing until the input level goes back to
normal and resumes the operation via a new soft start sequence.
The brown ? out comparator features a fixed voltage
reference level (V BO ). The hysteresis is implemented by
using the internal current connected between the BO pin and
the ground when the BO pin is below the internal voltage
reference (V BO ).
Vbulk
S
Q
Q
RB O u p
BO
BOK
R
shutdown
RB Olo
VBO
UVLO r eset
Grand
Reset
IBO
Figure 34. BO Pin Setup
V BO
V bulkON + R BOup I BO ) ) V BO
R BOlo
V BO +
V bulkoff R BOlo
R BOlo ) R BOup
V bulkoff * V BO
R BOup + R BOlo
V BO
The following equations show how to calculate the
resistors for BO pin.
First of all, select the bulk voltage value at which the
controller must start switching (V bulkon ) and the bulk
voltage for shutdown (V bulkoff ) the controller.
Where:
? V bulkon = 370 V
? V bulkoff = 350 V
? V BO = 1 V
? I BO = 10 m A
When BO pin voltage is below V BO (internal voltage
reference), the internal current source (I BO ) is activated. The
following equation can be written:
(eq. 1)
When BO pin voltage is higher than V BO , the internal
current source is now disabled. The following equation can
be written:
(eq. 2)
From Equation 2 it can be extracted the R BOup :
(eq. 3)
Equation 3 is substituted in Equation 1 and solved for
R BOlo , yields:
http://onsemi.com
13
相关PDF资料 |
PDF描述 |
|---|---|
| URS2G100MHD | CAP ALUM 10UF 400V 20% RADIAL |
| UPJ1A102MHD6 | CAP ALUM 1000UF 10V 20% RADIAL |
| AMM08DTBD-S664 | CONN EDGECARD 16POS R/A .156 |
| ASM22DRSI | CONN EDGECARD 44POS DIP .156 SLD |
| RSA30DRSD-S664 | CONN EDGECARD 60POS DIP .125 SLD |
相关代理商/技术参数 |
参数描述 |
|---|---|
| NCP1252TSFWDGEVB | 功能描述:电源管理IC开发工具 NCP1252 2-SWITCH FWD DB 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 |
| NCP1253 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Current-Mode PWM Controller for Off-line Power Supplies |
| NCP1253_12 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Current-Mode PWM Current-Mode PWM Power Supplies |
| NCP1253ASN100T1G | 功能描述:电流型 PWM 控制器 Current Mode PWM Offline Controller RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| NCP1253ASN65T1G | 功能描述:电流型 PWM 控制器 Current Mode PWM Offline Controller RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
发布紧急采购，3分钟左右您将得到回复。