參數資料
型號: NCP1200AP60
廠商: ON SEMICONDUCTOR
元件分類: 穩(wěn)壓器
英文描述: PWM Current-Mode Controller for Universal Off-Line Supplies Featuring Low Standby Power
中文描述: 0.25 A SWITCHING CONTROLLER, 68 kHz SWITCHING FREQ-MAX, PDIP8
封裝: PLASTIC, DIP-8
文件頁數: 8/16頁
文件大?。?/td> 136K
代理商: NCP1200AP60
NCP1200A
http://onsemi.com
8
Figure 16. A simple diode naturally reduces the average voltage on pin 8
8
7
6
5
1
2
3
4
mains
Cbulk
HV
Skipping Cycle Mode
The NCP1200A automatically skips switching cycles
when the output power demand drops below a given level.
This is accomplished by monitoring the FB pin. In normal
operation, pin 2 imposes a peak current accordingly to the
load value. If the load demand decreases, the internal loop
asks for less peak current. When this setpoint reaches a
determined level, the IC prevents the current from
decreasing further down and starts to blank the output
pulses: the IC enters the socalled skip cycle mode, also
named controlled burst operation. The power transfer now
depends upon the width of the pulse bunches (Figure 18).
Suppose we have the following component values:
Lp, primary inductance = 1 mH
F
SW
, switching frequency = 61 kHz
Ip skip = 200 mA (or 333 mV/R
SENSE
)
The theoretical power transfer is therefore:
1
2
If this IC enters skip cycle mode with a bunch length of
20 ms over a recurrent period of 100 ms, then the total
power transfer is: 1.2
.
0.2 = 240 mW.
Lp
Ip
2
FSW
1.2 W
To better understand how this skip cycle mode takes place,
a look at the operation mode versus the FB level
immediately gives the necessary insight:
Figure 17.
SKIP CYCLE OPERATION
I
P(min)
= 333 mV/R
SENSE
NORMAL CURRENT
MODE OPERATION
FB
1 V
4.2 V, FB Pin Open
3.2 V, Upper
Dynamic Range
When FB is above the skip cycle threshold (1 V by
default), the peak current cannot exceed 1 V/R
SENSE
. When
the IC enters the skip cycle mode, the peak current cannot go
below Vpin1 / 3.3. The user still has the flexibility to alter
this 1 V by either shunting pin 1 to ground through a resistor
or raising it through a resistor up to the desired level.
Grounding pin 1 permanently invalidates the skip cycle
operation.
Power P1
Power P2
Power P3
Figure 18. Output Pulses at Various Power Levels (X = 5.0 s/div) P1
P2
P3
相關PDF資料
PDF描述
NCP1200AP60G PWM Current-Mode Controller for Universal Off-Line Supplies Featuring Low Standby Power
NCP1200D PWM Current-Mode Controller for Universal Off-Line Supplies Featuring Low Standby Power
NCP1200AD100R2 PWM Current-Mode Controller for Universal Off-Line Supplies Featuring Low Standby Power
NCP1200AD100R2G PWM Current-Mode Controller for Universal Off-Line Supplies Featuring Low Standby Power
NCP1200AD40R2 PWM Current-Mode Controller for Universal Off-Line Supplies Featuring Low Standby Power
相關代理商/技術參數
參數描述
NCP1200AP60G 功能描述:IC CTRLR PWM CM HV 8DIP RoHS:是 類別:集成電路 (IC) >> PMIC - AC-DC 轉換器,離線開關 系列:- 標準包裝:1 系列:FPS™ 輸出隔離:隔離 頻率范圍:61kHz ~ 73kHz 輸入電壓:8 V ~ 26 V 輸出電壓:650V 功率(瓦特):12W 工作溫度:-40°C ~ 115°C 封裝/外殼:8-DIP(0.300",7.62mm) 供應商設備封裝:8-MDIP 包裝:Digi-Reel® 其它名稱:FSL206MRBNFSDKR
NCP1200D 制造商:ONSEMI 制造商全稱:ON Semiconductor 功能描述:PWM Current-Mode Controller for Universal Off-Line Supplies Featuring Low Standby Power
NCP1200D100R 制造商:Rochester Electronics LLC 功能描述: 制造商:ON Semiconductor 功能描述:
NCP1200D100R2 功能描述:電流型 PWM 控制器 100KHz Current Mode 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
NCP1200D100R2G 功能描述:電流型 PWM 控制器 100KHz Current Mode SMPS PWM 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