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參數資料
| 型號： | NCP1337 |
| 廠商： | ON SEMICONDUCTOR |
| 英文描述： | PWM Current−Mode Controller for Free Running Quasi−Resonant Operation |
| 文件頁數： | 7/14頁 |
| 文件大小： | 148K |
| 代理商： | NCP1337 |
NCP1337
http://onsemi.com
7
APPLICATION INFORMATION
INTRODUCTION
The NCP1337 implements a standard current mode
architecture where the switchoff time is dictated by the
peak current setpoint, whereas the corereset detection
triggers the turnon event. This component represents
the ideal candidate where low partcount is the key
parameter, particularly in lowcost ACDC adapters,
consumer electronics, auxiliary supplies, etc. Due to
its highperformance, highvoltage technology, the
NCP1337 incorporates all the necessary features needed to
build a rugged and reliable SwitchMode Power Supply
(SMPS):
QuasiResonant Operation:
Valleyswitching
operation is ensured whatever the operating conditions
are, due to the internal soxyless circuitry. As a result,
there are virtually no primary switch turnon losses,
and no secondary diode recovery losses, and EMI and
video noise perturbations are reduced. The converter
also stays a firstorder system and accordingly eases
the feedback loop design.
Dynamic SelfSupply (DSS):
Due to its Very High
Voltage Integrated Circuit (VHVIC) technology,
ON Semiconductor’s NCP1337 allows for a direct pin
connection to the highvoltage DC rail. A dynamic
current source charges up a capacitor and thus
provides a fully independent V
CC
level. As a result,
low power applications will not require any auxiliary
winding to supply the controller. In applications
where this winding is anyway required (see “Power
Dissipation” section in the application note), the DSS
will simplify the V
CC
capacitor selection.
Overcurrent Protection (OCP):
When the feedback
current is below minimum value, a fault is detected. If
this fault is present for more than 80 ms, NCP1337
enters an autorecovery soft burst mode. All pulses are
stopped and the V
CC
capacitor discharges down to
5.0 V. Then, by monitoring the V
CC
level, the startup
current source is activated ON and OFF to create a
burst mode. After the current source being activated
twice, the controller tries to restart, with a 4.0 ms
softstart. If the fault has gone, the SMPS resumes
operation. If the fault is still there, the burst sequence
starts again. The softstart, together with a minimum
frequency clamp, allow to reduce the noise generated
in the transformer in shortcircuit conditions.
Overvoltage Protection (OVP):
By continuously
monitoring the V
CC
voltage level, the NCP1337 stops
switching whenever an overvoltage condition is
detected.
BrownOut Detection (BO):
By monitoring the level
on Pin 1 during normal operation, the controller
protects the SMPS against low mains condition. When
Pin 1 level falls below 500 mV, the controller stops
pulsing until this level goes back and resumes
operation. By adjusting the resistor divider connected
between the high input voltage and this pin, start and
stop levels are programmable.
Over Power Compensation (OPC):
An internal
current source injects out of Pin 3 (CS pin) a current
proportional to the voltage applied on Pin 1. As this
voltage is an image of the input voltage, by inserting a
resistor in series with Pin 3, it is possible to create an
offset on the current sense signal that will compensate
the effect of the input voltage variation.
External Latch Trip Point:
By externally forcing a
level on Pin 1 (e.g., with a signal coming from a
temperature sensor) greater than 3.0 V (but below
5.0 V), it is possible to disable the output of the
controller. If the voltage is forced over 5.0 V, the
controller is permanently latchedoff: to resume
normal operation, the V
CC
voltage should go below
4.0 V, which implies to unplug the SMPS from the
mains.
Standby Ability:
Under low load conditions,
NCP1337 enters a SoftSkip mode: when the CS
setpoint becomes lower than 20% of the maximum
peak current, output pulses are stopped, then switching
is starting again when FB loop forces a setpoint higher
than 25%. As this occurs at low peak current, with
SoftSkip activated, and as the T
OFF
is clamped,
noisefree operation is guaranteed, even with a cheap
transformer.
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相關代理商/技術參數 |
參數描述 |
|---|---|
| NCP1337_11 | 制造商:ONSEMI 制造商全稱:ON Semiconductor 功能描述:PWM Current-Mode Controller for Free Running Quasi-Resonant Operation |
| NCP1337ADAPEVB | 功能描述:插座和適配器 NCP1337 60W ADAPTER EVB RoHS:否 制造商:Silicon Labs 產品:Adapter 用于:EM35x |
| NCP1337ADAPGEVB | 功能描述:電源管理IC開發工具 NCP1337 60W ADAPTER EVB RoHS:否 制造商:Maxim Integrated 產品:Evaluation Kits 類型:Battery Management 工具用于評估:MAX17710GB 輸入電壓: 輸出電壓:1.8 V |
| NCP1337DR2G | 功能描述:電流型 PWM 控制器 PWM CONTROLLER RoHS:否 制造商:Texas Instruments 開關頻率:27 KHz 上升時間: 下降時間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數量:1 最大工作溫度:+ 105 C 安裝風格:SMD/SMT 封裝 / 箱體:TSSOP-14 |
| NCP1337PG | 功能描述:電流型 PWM 控制器 PWM CONTROLLER RoHS:否 制造商:Texas Instruments 開關頻率:27 KHz 上升時間: 下降時間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數量:1 最大工作溫度:+ 105 C 安裝風格:SMD/SMT 封裝 / 箱體:TSSOP-14 |
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