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參數(shù)資料
| 型號： | NCP1217P65 |
| 廠商： | ON SEMICONDUCTOR |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | Enhanced PWM Current-Mode Controller for High-Power Universal Off-Line Supplies |
| 中文描述： | 0.5 A SWITCHING CONTROLLER, 71.5 kHz SWITCHING FREQ-MAX, PDIP7 |
| 封裝： | PLASTIC, DIP-8/7 |
| 文件頁數(shù)： | 8/18頁 |
| 文件大?。?/td> | 206K |
| 代理商： | NCP1217P65 |
NCP1217, NCP1217A
http://onsemi.com
8
APPLICATION INFORMATION
Introduction
The NCP1217 implements a standard current mode
architecture where the switchoff event is dictated by the
peak current setpoint. This component represents the ideal
candidate where low partcount is the key parameter,
particularly in lowcost AC/DC adapters, TV power
supplies, etc. Due to its highperformance HighVoltage
technology, the NCP1217 incorporates all the necessary
components normally needed in UC384X based supplies:
timing components, feedback devices, lowpass filter and
startup device but also enhances the original component
by offering: 1) an externally triggerable latchoff
2) ramp compensation and finally, 3) shortcircuit
protection. Due to its highvoltage current source,
ON Semiconductor’s NCP1217 does not need an external
startup resistance but supplies the startup current directly
from the highvoltage rail. On the other hand, more and
more applications are requiring low noload standby power,
e.g. for AC/DC adapters, VCRs, etc. UC384X series have a
lot of difficulty to reduce the switching losses at low power
levels. NCP1217 elegantly solves this problem by skipping
unwanted switching cycles at a useradjustable power level.
By ensuring that skip cycles take place at low peak current,
the device ensures quiet, noisefree operation:
CurrentMode Operation:
As the UC384X series, the
NCP1217 features a wellknown current mode control
architecture which provides superior input audio
susceptibility compared to traditional voltagemode
controllers. Primary current pulsebypulse checking
together with a fast over current comparator offers greater
security in the event of a difficult fault condition, e.g. a
saturating transformer.
Ramp Compensation:
By inserting a resistor between the
currentsense (CS) pin and the actual sense resistor, it
becomes possible to inject a given amount of ramp
compensation since the internal saw tooth clock is routed to
the CS pin. Subharmonic oscillations in Continuous
Conduction Mode (CCM) can thus be compensated via a
single resistor.
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 noisefree
operation with cheap transformers. Skip cycle offers a
proven mean to reduce the standby power in no or light loads
situations.
Wide SwitchingFrequency Offer:
Three different options
are available: 65 kHz–100 kHz–133 kHz. Depending on the
application, the designer can pick up the right device to help
reducing magnetics or improve the EMI signature before
reaching the 150 kHz starting point.
Overcurrent Protection (OCP):
By continuously
monitoring the V
CC
auxiliary winding voltage, NCP1217
enters burst mode as soon as the power supply undergoes an
overload: when the V
CC
voltage goes down until it crosses
the undervoltage lockout level (VCC
min
). When the
NCP1217 reaches this level (typically 7.6 V), it stops the
switching pulses until the V
CC
pin voltage reaches VCC
latch
(5.6 V). At VCC
latch
, the NCP1217 attempts to restart. As
soon as the default disappears, the power supply resumes
operation.
Overvoltage Protection (OVP):
If pin1 is brought to a level
higher than the internal 3.2 V reference voltage, the
controller is permanently shut down until the user cycles the
VCC OFF and ON again. This allows the building of
efficient and lowcost over voltage protection circuits.
Wide DutyCycle Operation:
Wide mains operation
requires a large dutycycle excursion. The NCP1217 can go
up to 74% typically.
Low StandbyPower:
If SMPS naturally exhibit a good
efficiency at nominal load, they begin to be less efficient
when the output power demand diminishes. By skipping
unneeded switching cycles, the NCP1217 drastically
reduces the power wasted during light load conditions. In
noload conditions, the NPC1217 allows the total standby
power to easily reach next International Energy Agency
(IEA) recommendations.
No Acoustic Noise While Operating:
Instead of skipping
cycles at high peak currents, the NCP1217 waits until the
peak current demand falls below a useradjustable 1/3 of the
maximum limit. As a result, cycle skipping can take place
without having a singing transformer
…
You can thus select
cheap magnetic components free of noise problems.
External MOSFET Connection:
By leaving the external
MOSFET external to the IC, you can select avalanche proof
devices, which in certain cases (e.g. low output powers), let
you work without an active clamping network. Also, by
controlling the MOSFET gate signal flow, you have an
option to slow down the device commutation, therefore
reducing the amount of ElectroMagnetic Interference
(EMI).
SPICE Model:
A dedicated model to run transient
cyclebycycle simulations is available but also an
averaged version to help you closing the loop. Readytouse
templates can be downloaded in OrCAD’s Pspice and
INTUSOFT’s IsSpice from ON Semiconductor web site,
NCP1217 related section.
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相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| NCP1217P65G | 功能描述:電流型 PWM 控制器 Enhanced Current Mode PWM RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時(shí)間: 下降時(shí)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(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14 |
| NCP1218 | 制造商:ONSEMI 制造商全稱:ON Semiconductor 功能描述:PWM Controller with Adjustable Skip Level and External Latch Input |
| NCP1218AD65R2G | 功能描述:電流型 PWM 控制器 ANA PWM CONTROLLER RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時(shí)間: 下降時(shí)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(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14 |
| NCP1219 | 制造商:ONSEMI 制造商全稱:ON Semiconductor 功能描述:PWM Controller with Adjustable Skip Level and External Latch Input |
| NCP1219AD100R2G | 功能描述:電流型 PWM 控制器 ANA PWM CONTROLLER RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時(shí)間: 下降時(shí)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(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14 |
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