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參數(shù)資料
| 型號(hào)： | NCP1200P100G |
| 廠商： | ON SEMICONDUCTOR |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | PWM Current-Mode Controller for Low-Power Universal Off-Line Supplies |
| 中文描述： | 0.25 A SWITCHING CONTROLLER, 116 kHz SWITCHING FREQ-MAX, PDIP8 |
| 封裝： | LEAD FREE, PLASTIC, DIP-8 |
| 文件頁數(shù)： | 7/16頁 |
| 文件大?。?/td> | 151K |
| 代理商： | NCP1200P100G |
NCP1200
http://onsemi.com
7
APPLICATIONS INFORMATION
INTRODUCTION
The NCP1200 implements a standard current mode
architecture where the switchoff time is dictated by the
peak current setpoint. This component represents the ideal
candidate where low partcount is the key parameter,
particularly in lowcost ACDC adapters, auxiliary
supplies etc. Due to its highperformance HighVoltage
technology, the NCP1200 incorporates all the necessary
components normally needed in UC384X based supplies:
timing components, feedback devices, lowpass filter and
selfsupply. This later point emphasizes the fact that ON
Semiconductor’s NCP1200 does NOT need an auxiliary
winding to operate: the product is naturally supplied from
the highvoltage rail and delivers a V
CC
to the IC. This
system is called the Dynamic SelfSupply (DSS).
Dynamic SelfSupply
The DSS principle is based on the charge/discharge of the
V
CC
bulk capacitor from a low level up to a higher level. We
can easily describe the current source operation with a bunch
of simple logical equations:
POWERON: IF V
CC
< V
CCOFF
THEN Current Source
is ON, no output pulses
IF V
CC
decreasing > V
CCON
THEN Current Source is
OFF, output is pulsing
IF V
CC
increasing < V
CCOFF
THEN Current Source is
ON, output is pulsing
Typical values are: V
CCOFF
= 11.4 V, V
CCON
= 9.8 V
To better understand the operational principle, Figure 15’s
sketch offers the necessary light:
10.00M
Figure 15. The Charge/Discharge Cycle
Over a 10 F V
CC
Capacitor
30.00M
50.00M
70.00M
90.00M
Current
Source
OFF
V
CC
ON
10.6 V Avg.
Output Pulses
V
CCON
= 9.8 V
V
CCOFF
= 11.4 V
The DSS behavior actually depends on the internal IC
consumption and the MOSFET’s gate charge, Qg. If we
select a MOSFET like the MTD1N60E, Qg equals 11 nC
(max). With a maximum switching frequency of 48 kHz (for
the P40 version), the average power necessary to drive the
MOSFET (excluding the driver efficiency and neglecting
various voltage drops) is:
Fsw
Qg
V
cc
with
Fsw = maximum switching frequency
Qg = MOSFET’s gate charge
V
CC
= V
GS
level applied to the gate
To obtain the final driver contribution to the IC
consumption, simply divide this result by V
CC
: Idriver =
Fsw
Qg
= 530 A. The total standby power consumption
at noload will therefore heavily rely on the internal IC
consumption plus the above driving current (altered by the
driver’s efficiency). Suppose that the IC is supplied from a
400 V DC line. To fully supply the integrated circuit, let’s
imagine the 4 mA source is ON during 8 ms and OFF during
50 ms. The IC power contribution is therefore: 400 V
.
4 mA
.
0.16 = 256 mW. If for design reasons this contribution is
still too high, several solutions exist to diminish it:
1. Use a MOSFET with lower gate charge Qg
2. Connect pin through a diode (1N4007 typically) to
one of the mains input. The average value on pin 8
becomes
2 * Vmains PEAK
. Our power contribution
example drops to: 160 mW.
C3
4.7 F
400 V
+
EMI
Filter
Adj
FB
CS
GND Drv
V
CC
NC
HV
1
2
3
4
8
7
6
5
NCP1200
1N4007
Dstart
Figure 16. A simple diode naturally reduces the
average voltage on pin 8
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| NCP1200D60R2G | PWM Current-Mode Controller for Low-Power Universal Off-Line Supplies |
| NCP1200D40R2G | PWM Current-Mode Controller for Low-Power Universal Off-Line Supplies |
| NCP1201D100R2G | PWM Current−Mode Controller for Universal Off−Line Supplies Featuring Low Standby Power with Fault Protection Modes |
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相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| NCP1200P100G | 制造商:ON Semiconductor 功能描述:Pulse Width Modulation (PWM) Controller |
| NCP1200P100R2G | 制造商:ON Semiconductor 功能描述: |
| NCP1200P40 | 功能描述:電流型 PWM 控制器 40KHz Current Mode 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 |
| NCP1200P40G | 功能描述:電流型 PWM 控制器 40KHz Current Mode SMPS 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 |
| NCP1200P40G | 制造商:ON Semiconductor 功能描述:Pulse Width Modulation (PWM) Controller |
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