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参数资料
| 型号： | NCP1378DR2 |
| 厂商： | ON Semiconductor |
| 文件页数： | 7/15页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR FLYBACK PWM 8-SOIC |
| 产品变化通告： | LTB Notification 03/Jan/2008 |
| 标准包装： | 2,500 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 100kHz |
| 电源电压： | 8.2 V ~ 18 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： | 无 |
| 工作温度： | 0°C ~ 125°C |
| 封装/外壳： | 8-SOIC（0.154"，3.90mm 宽） |
| 包装： | 带卷 (TR) |
| 其它名称： | NCP1378DR2OS |
NCP1378
APPLICATION INFORMATION
INTRODUCTION
The NCP1378 implements a standard current mode
architecture where the switch-- off time is dictated by the
peak current setpoint, whereas the core reset detection
triggers the turn-- on event . This component represents the
ideal candidate where low part-- count is the key parameter
in applications supplied by a battery. Due to its high--
performance High-- Voltage technology, the NCP1378
incorporates all the necessary components/features needed
to build a rugged and reliable Switchmode Power Supply
(SMPS):
? Transformer Core Reset Detection: Borderline/critical
operation is ensured whatever the operating conditions
are. As a result, there are virtually no primary switch
turn-- on losses and no secondary diode recovery
losses. The converter also stays a first-- order system
and accordingly eases the feedback loop design.
? Quasi-- Resonant Operation: By delaying the turn-- on
event, it is possible to restart the MOSFET in the
minimum of the drain-- source wave, ensuring reduced
EMI/video noise perturbations. In nominal power
conditions, the NCP1378 operates in Borderline
Conduction Mode (BCM) also called Critical
Conduction Mode.
? Undervoltage Lockout (UVLO): When V CC falls
below UVLO, all pulses are stopped and the IC
consumption drops down to a few hundreds of m A
(ICC3 data). When V CC reaches the latchoff level
(5.5 V typical), the startup current source is activated
and brings V CC back to VCC ON where the IC attempts
to startup.
? Adjustable Skip Cycle Level: By offering the ability
to tailor the level at which the skip cycle takes place,
the designer can make sure that the skip operation
only occurs at low peak current. This point guarantees
a noise--free operation with cheap transformer. This
option also offers the ability to fix the maximum
switching frequency when entering light load conditions.
? Overcurrent Protection (OCP): NCP1378 enters burst
mode as soon as the power supply undergoes an
overload, which is detected through the sense of the
auxiliary voltage. As detailed above, as soon as V CC
crosses the UVLO level (called VCC OFF in the
electrical table), all pulses are stopped and the device
enters a safe low power operation that prevents from
any lethal thermal runaway. By monitoring the V CC
level, the startup current source is activated ON and
OFF to create a kind of burst mode where the SMPS
tries to restart. If the fault has gone, the SMPS
resumes operation. On the other hand, if the fault is
still there, the burst sequence starts again.
Startup Sequence
When the power supply is first powered from the mains
outlet, the internal current source (typically 4.0 mA) is
biased and charges up the V CC capacitor. When the voltage
on this V CC capacitor reaches the VCC ON level (typically
8.4 V), the current source turns off and no longer wastes
any power. At this time, the V CC capacitor only supplies the
controller and the auxiliary supply is supposed to take over
before V CC collapses below V CCOFF . Figure 15 shows the
internal arrangement of this structure.
? Overvoltage Protection (OVP): By sampling the
plateau voltage on the demagnetization winding, the
NCP1378 goes into latched fault condition whenever
an over-- voltage condition is detected. The controller
stays fully latched in this position until the V CC is
cycled down to 4.0 V, e.g. when the user unplugs the
V CCON /V CCOFF
+
--
8
IC1 or 0
6
HV
SVCC
Aux
power supply from the mains outlet and replugs it.
? External LatchTrip Point: By externally forcing a
level on the OVP greater than the internal setpoint, it
is possible to latchoff the IC, e.g. with a signal coming
from a temperature sensor.
4
Figure 15. The Current Source Brings Vcc Above
Vcc ON and Then Turns Off
http://onsemi.com
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相关代理商/技术参数 |
参数描述 |
|---|---|
| NCP1378DR2G | 功能描述:电流型 PWM 控制器 Quasi Resonant Current Mode PWM 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 |
| NCP1378P | 功能描述:电流型 PWM 控制器 Quasi Resonant 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 |
| NCP1378PG | 功能描述:电流型 PWM 控制器 Quasi Resonant Current Mode PWM 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 |
| NCP1379 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Quasi-Resonant Current-Mode Controller for High-Power Universal Off-line Supplies |
| NCP1379_11 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Quasi-Resonant Current-Mode Controller for High-Power Universal Off-line Supplies |
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