OB276N

GENERAL DESCRIPTION

OB276N is a high performance, high precision and low cost off-line switcher with enhanced flexibility and extended power range. It combines a dedicated on/off switch controller with a high voltage power MOSFET in DIP7 package. Its on/off control scheme is optimized for good overshoot and dynamic response for low cost and component count. With precise current sensor,  precise on/off control scheme， constant current  at universal AC input can be guaranteed. Good EMI performance is achieved with On-Bright proprietary frequency shuffling technique and soft gate driver design. Low startup current and low operating current contribute to a reliable power on startup and low standby power consumption with OB276N.

OB276N offers power on soft start control and protection coverage with auto-recovery features including cycle-by-cycle current limiting, output short circuit protection, on-chip Over Temperature Protection (OTP), VDD Over Voltage Protection (OVP), Over Loading Protection(OLP) and VDD Under Voltage Lockout Protection (UVLO).

OB276N is offered in DIP7 package.

FEATURES

·         Simple ON/OFF control, no loop compensation needed.

·         Low cost and less BOM for off-line Switcher applications

·         Current mode control

·         132kHz (typical) maximum switching frequency

·         Frequency shuffling for EMI improvement

·         Power on soft-start 

·         No load<200mW at 265VAC, Without bias winding, <50mW with bias winding.

·         Built-in Leading Edge Blanking (LEB)

·         Cycle-by-cycle current limiting

·         Output short-circuit protection

·         VDD Under Voltage Lockout with Hysteresis

·         VDD OVP

·         Over Loading Protection

·         On-Chip OTP

 

 

APPLICATIONS

·         Chargers/adapters for cell/cordless phones, PDAs, digital cameras, MP3/portable audio, shavers, etc.

 

 

 

TYPICAL APPLICATION

GENERAL INFORMATION

 

Pin Configuration

The pin map is shown as below for DIP7

Ordering Information

Part Number	Description
OB276NASP-V	DIP7, Halogen-free, Tube

Package Dissipation Rating

Package	RθJA   (℃/W)
DIP7	75

Note: Drain Pin Connected 100mm² PCB copper clad.

Recommended Operating Condition

Symbol	Parameter	Range
VDD	VDD Supply Voltage	8.5-15V

Output Power Table

Flyback	85~275Vac (Adapter)	176~275Vac (Adapter)
OB276N	7W	10W

Notes: Maximum practical continuous power in an adapter design with sufficient drain pattern as a heat sink, at 40℃ambient.

Absolute Maximum Ratings

Parameter	Value
SW Voltage(off state)	-0.3V to 700V
VDD Input Voltage	-0.3V to 22V
FB Input Voltage	-0.3V to 7V
Min/Max Operating Junction Temperature TJ	-40 to 150 ℃
Min/Max Storage Temperature Tstg	-55 to 150 ℃
Lead Temperature (Soldering, 10secs)	260 ℃

Note: Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute maximum-rated conditions for extended periods may affect device reliability.

 

 
 

Marking Information

 

TERMINAL ASSIGNMENTS

Pin   Num	Pin   Name	I/O	Description
1	FB	I	Feedback   pin
2	VDD	P	Power   Supply
4	SW	I	Power MOSFET   Drain pin
5/6/7/8	GND	P	Ground