WIS2269N8
Current Mode PWM Controller
GERNERAL DESCRIPTION
WIS2269 is a highly integrated, high performance current
mode PWM controller chip. Apply to the power adapter and
other small and medium-power switch power supply.
In order to reduce standby power consumption to meet the
higher standards of environmental protection, the chip
provides a pulse mode (Burst Mode) function, very low starting
current and operating current. Pulse mode that is in the light
load or no load conditions, WIS2269 can linearly decrease the
switching frequency chip, thereby reducing switching loss; by
optimizing the design, WIS2269 has a very low starting current
and operating current, is not only beneficial to start the circuit
design, and the start circuit can be used in high-value startup
resistor, to reduce power consumption, improve power
conversion efficiency.
WIS2269 built-in synchronized slope compensation circuit,
to prevent the PWM controller when working in high-duty cycle
may have harmonic oscillation. WIS2269 side in the current
sample input pin edge blanking function built in, can effectively
remove the current feedback signal of the glitch. Help to
reduce the number of external components, reducing overall
system cost.
WIS2269 offers a variety of comprehensive resume
protection mode, including:-by-cycle current limit protection
(OCP), over-load protection (OLP), VDD over-voltage
clamping voltage and low voltage closed (UVLO). Which, in
order to better protect the external MOSFET power transistor,
the gate drive output voltage is clamped at 18V.
WIS2269 the totem pole gate drive output using a frequency
jitter control technology and soft-switching technology, can be
very good to improve EMI performance switching power
supply system. By optimizing the design, when the chip's
operating frequency less than 20KHz circumstances, the
audio energy can be reduced to a minimum. Therefore, the
audio can get greatly improved noise performance.
WIS2269-chip can be used as RCC-mode power supply
linear power supply or the best alternative to enhance the
overall performance of switching power supply system, and
effectively reduce the system cost.
FEATURES
■
Burst Mode function
■
Low startup current (6.5uA)
■
Low operating current (2.3mA)
■
Built-edge blanking
■
Built-in synchronized slope compensation
■
Current mode
■
External Programmable PWM Switching Frequency
■
By-cycle current limit protection (OCP)
■
VDD over-voltage clamping protection
■
Low voltage shut down function (UVLO)
■
Gate Drive Output Voltage Clamp (18V)
■
Frequency jitter feature
■
Constant output power limit
■
Overload protection (OLP)
■
Work does not produce audio noise
APPLICATIONS
Offline AC/DC flyback converter for
■
Power Adaptor
■
Open-frame SMPS
■
Battery Charger
■
Set-Top Box Power Supplies
TYPICAL APPLICATION
WIS2269
TL431
Rev. A Mar.2010
P02-1
WINSEMI [ SHENZHEN WINSEMI MICROELECTRONICS CO., LTD ]
