TEA1750T/N1,518【PDF 16/29 页】IC PFC CONTROLLER DCM16SOIC

收藏本站

您好，
买卖IC网欢迎您。
请登录
免费注册

买卖IC网

Sheet目录46

12页 13页 14页 15页 [16页]17页 18页 19页 20页

TEA1750_2

Product data sheet

Rev. 02 15 December 2008

16 of 29

NXP Semiconductors

TEA1750

GreenChip III SMPS control IC

7.3.6 Soft start-up (pin FBSENSE)

To prevent audible transformer noise during start-up, the transformer peak current, I

slowly increased by the soft start function. This can be achieved by inserting a resistor

and a capacitor between pin FBSENSE and the current sense resistor.

An internal current source charges the capacitor to V = I

start(soft)(fb)

x R

SS2

, with a

maximum of approximately 0.5 V.

The start level and the time constant of the increasing primary current level can be

adjusted externally by changing the values of R

SS2

and C

SS2

The soft start current I

start(soft)(fb)

is switched on as soon as V

reaches V

startup

. When the

voltage on the VOSENSE pin reaches the V

start(fb)

level and the voltage on pin FBSENSE

has reached 0.5 V, the yback converter starts switching.

The soft start current ows as long as the voltage on pin FBSENSE is below

approximately 0.5 V. If the voltage on pin FBSENSE exceeds 0.5 V, the soft start current

source starts limiting the current. After the yback converter has started, the soft start

current source is switched off.

a. Circuit diagram

b. Timing diagram

Fig 11. Time-out protection

014aaa049

FBCTRL

2.5 V

4.5 V

30 礎

3 k&

3.5 V

TIMEOUT

014aaa050

4.5 V

2.5 V

FBCTRL

output

voltage

intended output

voltage not

reached within

time-out time.

intended output voltage

reached within time-out

time.

restart

?/DIV>

SoftStart

3 R

SS2

?/DIV>

SS2

?/DIV>

发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

*型号	*数量	厂商	批号	封装

添加更多采购

采购需求

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

我的联系方式