- 您现在的位置：买卖IC网 > PDF目录19612 > NCP1271P100G (ON Semiconductor)IC CTRLR PWM CM OVP OTP HV 7DIP PDF资料下载
参数资料
| 型号： | NCP1271P100G |
| 厂商： | ON Semiconductor |
| 文件页数： | 15/21页 |
| 文件大小： | 0K |
| 描述： | IC CTRLR PWM CM OVP OTP HV 7DIP |
| 标准包装： | 1,000 |
| 系列： | Soft-Skip™ |
| 输出隔离： | 隔离 |
| 频率范围： | 85kHz ~ 107kHz |
| 输入电压： | 10 V ~ 20 V |
| 工作温度： | -40°C ~ 125°C |
| 封装/外壳： | 8-DIP（0.300"，7.62mm），7 引线 |
| 供应商设备封装： | 7-PDIP |
| 包装： | 管件 |
NCP1271
% Icsskip + · 100%
Besides the timer ? based fault detection, the NCP1271
also enters fault condition when V CC drops below V CC (off )
(9.1 V typical). The device will again enter a double hiccup
mode and try to restart the application.
Operation in Standby Condition
During standby operation, or when the output has a light
load, the duty cycle on the controller can become very
small. At this point, a significant portion of the power
dissipation is related to the power MOSFET switching on
and off. To reduce this power dissipation, the NCP1271
“skips” pulses when the FB level (i.e. duty cycle) drops too
low. The level that this occurs at is completely adjustable
by setting a resistor on pin 1.
By discontinuing pulses, the output voltage slowly drops
and the FB voltage rises. When the FB voltage rises above
the V skip level, the drive is turned back on. However, to
minimize the risk of acoustic noise, when the drive turns
back on the duty cycle of its pulses are also ramped up. This
is similar to the soft start function, except the period of the
Soft ? Skip operation is only 300 m s instead of 4.0 ms for the
soft start function. This feature produces a timing diagram
shown in Figure 36.
Skip Duty Cycle
Skip peak current, %Ics skip , is the percentage of the
maximum peak current at which the controller enters skip
mode. Ics skip can be any value from 0 to 100% as defined
by equation 5. However, the higher that %Ics skip is, the
greater the drain current when skip is entered. This
increases the risk of acoustic noise. Conversely, the lower
that %Ics skip is the larger the percentage of energy is
expended turning the switch on and off. Therefore it is
important to adjust %Ics skip to the optimal level for a given
application.
Vskip (eq. 5)
3V
Skip Adjustment
By default, when the Skip/latch Pin (Pin 1) is opened, the
skip level is 1.2 V (V skip = 1.2 V). This corresponds to a
40% Ics skip (%Ics skip = 1.2 V / 3.0 V 100% = 40%).
Therefore, the controller will enter skip mode when the
peak current is less than 40% of the maximum peak current.
However, this level can be externally adjusted by placing
a resistor R skip between skip/latch pin (Pin 1) and Ground
(Pin 4). The level will change according to equation 6.
V skip
Vskip + Rskip
Iskip
(eq. 6)
FB
Soft Skip
To operate in skip cycle mode, V skip must be between
0 V and 3.0 V. Therefore, R skip must be within the levels
given in Table 1.
ID
Figure 36. Soft ? Skip Operation
Table 1. Skip Resistor R skip Range for D max = 80% and I skip = 43 m A
%Ics skip
0%
12%
25%
40%
50%
100%
V skip or V pin1
0V
0.375 V
0.75 V
1.2 V
1.5 V
3.0 V
R skip
0 W
8.7 k W
17.4 k W
28 k W
34.8 k W
70 k W
Never skips.
?
?
?
?
Always skips.
Comment
http://onsemi.com
15
相关PDF资料 |
PDF描述 |
|---|---|
| GEM06DRYN | CONN EDGECARD 12POS DIP .156 SLD |
| V300A5E400BL | CONVERTER MOD DC/DC 5V 400W |
| VI-20Z-CY-F3 | CONVERTER MOD DC/DC 2V 20W |
| VE-BVY-CX-F2 | CONVERTER MOD DC/DC 3.3V 49.5W |
| R1NW/BK | BATTERY EXTRA HEAVY DUTY N CELL |
相关代理商/技术参数 |
参数描述 |
|---|---|
| NCP1271P65G | 功能描述:电流型 PWM 控制器 ANA PMW 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 |
| NCP1271开关电源控制器 | 制造商:未知厂家 制造商全称:未知厂家 功能描述: |
| NCP1280 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Active Clamp Voltage Mode PWM Controller for Off-Line Applications |
| NCP1280/D | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Active Clamp Voltage Mode PWM Controller For Off-Line Applications |
| NCP1280_05 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Active Clamp Voltage Mode PWM Controller for Off-Line Applications |
发布紧急采购，3分钟左右您将得到回复。