NCP1200P100 datasheet(7/16 Pages) ONSEMI

Part #	NCP1200P100

Description	PWM Current-Mode Controller for Low-Power Universal Off-Line Supplies

Download	16 Pages

Scroll/Zoom	100%

Manufacturer	ONSEMI [ON Semiconductor]

Direct Link	http://www.onsemi.com

Logo

7 / 16 page

NCP1200

http://onsemi.com

7

APPLICATIONS INFORMATION

INTRODUCTION

The NCP1200 implements a standard current mode

architecture where the switch−off time is dictated by the

peak current setpoint. This component represents the ideal

candidate where low part−count is the key parameter,

particularly in low−cost AC−DC adapters, auxiliary

supplies etc. Due to its high−performance High−Voltage

technology, the NCP1200 incorporates all the necessary

components normally needed in UC384X based supplies:

timing components, feedback devices, low−pass filter and

self−supply. 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 high−voltage rail and delivers a VCC to the IC. This

system is called the Dynamic Self−Supply (DSS).

Dynamic Self−Supply

The DSS principle is based on the charge/discharge of the

VCC 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:

POWER−ON: IF VCC < VCCOFF THEN Current Source

is ON, no output pulses

IF VCC decreasing > VCCON THEN Current Source is

OFF, output is pulsing

IF VCC increasing < VCCOFF THEN Current Source is

ON, output is pulsing

Typical values are: VCCOFF = 11.4 V, VCCON = 9.8 V

To better understand the operational principle, Figure 15’s

sketch offers the necessary light:

10.00M

30.00M

50.00M

70.00M

90.00M

Current

Source

OFF

Figure 15. The Charge/Discharge Cycle

Over a 10

mF VCC Capacitor

VCC

ON

10.6 V Avg.

Output Pulses

VCCON = 9.8 V

VCCOFF = 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 @ Vcc

with

Fsw = maximum switching frequency

Qg = MOSFET’s gate charge

VCC = VGS level applied to the gate

To obtain the final driver contribution to the IC

consumption, simply divide this result by VCC: Idriver =

Fsw

@ Qg = 530

mA. The total standby power consumption

at no−load 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

p

. Our power contribution

example drops to: 160 mW.

C3

4.7

mF

400 V

+

EMI

Filter

Adj

FB

CS

GND Drv

VCC

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

Similar Part No. - NCP1200P100

Manufacturer	Part #	Datasheet	Description
ON Semiconductor	NCP1200P100	225Kb / 16P	PWM Current?묺ode Controller for Low?뭁ower Universal Off?묹ine Supplies September, 2006 ??Rev. 15
	NCP1200P100G	225Kb / 16P	PWM Current?묺ode Controller for Low?뭁ower Universal Off?묹ine Supplies September, 2006 ??Rev. 15
	NCP1200P100G	287Kb / 16P	PWM Current-Mode Controller for Low-Power Universal Off-Line Supplies April, 2015 ??Rev. 19
	NCP1200P100G	432Kb / 18P	PWM Current-Mode Controller for Low-Power Universal Off-Line Supplies April, 2015 - Rev. 19

More results

Similar Description - NCP1200P100

Manufacturer	Part #	Datasheet	Description
ON Semiconductor	NCP1200	287Kb / 16P	PWM Current-Mode Controller for Low-Power Universal Off-Line Supplies April, 2015 ??Rev. 19
	NCP1200	432Kb / 18P	PWM Current-Mode Controller for Low-Power Universal Off-Line Supplies April, 2015 - Rev. 19
	NCP1200	359Kb / 16P	PWM Current-Mode Controller for Low-Power Universal Off-Line Supplies December, 2009 ??Rev. 17
	NCP1216P065	287Kb / 18P	PWM Current-Mode Controller for High-Power Universal Off-Line Supplies December, 2010 ??Rev. 13
	DAP011	827Kb / 24P	PWM Current−Mode Controller for High−Power Universal Off−Line Supplies November, 2005 - Rev. 2
	DAP018A	792Kb / 28P	PWM Current-Mode Controller for High-Power Universal Off-Line Supplies July, 2009 - Rev. 0
	NCP1216	182Kb / 18P	PWM Current-Mode Controller for High-Power Universal Off-Line Supplies September, 2004 ??Rev. 8
	NCP1216	276Kb / 18P	PWM Current-Mode Controller for High-Power Universal Off-Line Supplies December, 2010 ??Rev. 13
	NCP1216AP100G	276Kb / 18P	PWM Current-Mode Controller for High-Power Universal Off-Line Supplies December, 2010 ??Rev. 13
	NCP1200A	136Kb / 16P	PWM Current-Mode Controller for Universal Off-Line Supplies Featuring Low Standby Power October, 2004??Rev. 5

More results

NCP1200P100 Datasheet(PDF) 7 Page - ON Semiconductor

NCP1200P100 Datasheet(HTML) 7 Page - ON Semiconductor

Similar Part No. - NCP1200P100

Similar Description - NCP1200P100

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Datasheet Download

Link URL