[ 本帖最后由 ggggdso 于 2008-11-7 10:07 編輯 ]作者: xcm885995 時(shí)間: 2009-1-4 21:31 標題: LD7550-B DATASHEET Green-Mode PWM Controller
General Description
The LD7550-B is a low cost, low startup current, current
mode PWM controller with green-mode power-saving
operation. The integrated functions such as the
leading-edge blanking of the current sensing, internal slope
compensation and the small SOT-26 package provide the
users a high efficiency, low external component counts, and
low cost solution for AC/DC power applications.
Compared with LD7550, LD7550-B has different parameters
or functions on the following characteristics ---
􀁺 Enlarger the hysteresis range of UVLO by lowering
down the UVLO(off) from 11.4V to 10V.
􀁺 Add OVP (Over Voltage Protection) function on Vcc
Pin.
􀁺 Shorten the OCP delay time to 100nS to reduce the
difference of OCP trip level under high line & low line.
Features
􀁺 High-Voltage CMOS Process with Excellent ESD
protection
􀁺 Very Low Startup Current (<20μA)
􀁺 Under Voltage Lockout (UVLO)
􀁺 Current Mode Control with Cycle-by-Cycle Peak
Current Limiting
􀁺 Leading-Edge Blanking on CS Pin
􀁺 Programmable Switching Frequency
􀁺 Internal Slope Compensation
􀁺 Proprietary Green-Mode Control for Power Saving
􀁺 Non-audible-noise Green Mode Control
􀁺 300mA Driving Capability
􀁺 OVP (Over Voltage Protection) on Vcc Pin
Applications
􀁺 Switching AC/DC Adaptor and Battery Charger
􀁺 Open Frame Switching Power Supply
􀁺 384X Replacement
Typical Application
OSC
16.0V/
10.0V
UVLO
Divider
Control
Logic
EMI
Filter
RT
OUT
CS
VCC
GND
COMP
LD7550-B
photocoupler
AC
input
TL431作者: et-mac 時(shí)間: 2009-1-31 23:17
:-(
........................................作者: et-mac 時(shí)間: 2009-1-31 23:18
++++++++
.................................作者: et-mac 時(shí)間: 2009-1-31 23:19
樓主請聯(lián)系。謝謝！作者: phtaoyin 時(shí)間: 2010-12-25 22:40
b樓主請聯(lián)系。謝謝！