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OB2283
High Performance Current Mode PWM Controller
GENERAL DESCRIPTION
OB2283 is a highly integrated current mode PWM control IC optimized for high performance, low standby power and cost effective offline flyback converter applications. PWM switching frequency at normal operation is internally fixed and is trimmed to tight range. At no load or light load condition, the IC operates in extended ‘burst mode’ to minimize switching loss. Lower standby power and higher conversion efficiency is thus achieved. VCC low startup current and low operating current contribute to a reliable power on startup and low standby design with OB2283. OB2283 offers comprehensive protection coverage with auto-recovery including Cycle-byCycle current limiting (OCP), over load protection (OLP), and VCC under voltage lockout (UVLO). It also provides the protections with latched shut down including over temperature protection (OTP), and over voltage protection (OVP). Excellent EMI performance is achieved with On-Bright proprietary frequency shuffling technique. The tone energy at below 25KHz is minimized in the design and audio noise is eliminated during operation. OB2283 is offered in SOT23-6 package.
APPLICATIONS
Offline AC/DC flyback converter for ■ Printer, Storage power supply ■ Power Adapter
FEATURES
■ Power on soft start reducing MOSFET Vds stress
■ Frequency shuffling for EMI ■ Extended burst mode control for improved
efficiency and low standby power design ■ Audio noise free operation ■ Peak load operation with increased frequency ■ Comprehensive protection coverage
o VCC Under Voltage Lockout with hysteresis (UVLO)
o VCC Over Voltage Protection (VCC OVP) o Cycle-by-cycle over current threshold
setting for constant output power limiting over universal input voltage range o Over Load Protection (OLP) with autorecovery o External (if NTC resistor is connected at PRT pin)or internal Over Temperature Protection (OTP) with latched shut down o Output Over Voltage Protection(Output OVP) with latched shut down, and the OVP triggered voltage can be adjusted by the resistor connected between auxiliary winding and PRT pin o Output diode short protection with autorecovery o GND open protection with auto-recovery
TYPICAL APPLICATION
AC IN
EMI Filter
OB2283
6 FB VCC 1
5 PRT
CS 2
4 GND GATE 3
Vaux
DC Out
©On-Bright Electronics
Confidential -1-
Preliminary Datasheet OB_DOC_DS_228300
OB2283
High Performance Current Mode PWM Controller
GENERAL INFORMATION
Pin Configuration
VCC CS
Gate
1 2 3
6 FB 5 PRT 4 GND
Ordering Information
Part Number OB2283MP
Description SOT23-6, Pb-free in T&R
Package Dissipation Rating
Package
RJA(℃/W)
SOT23-6
200
Recommended operating condition
Symbol Parameter
Range
VCC
VCC Supply Voltage 12 to 28V
TA
Operating Ambient Temperature
-20 to 85 ℃
Absolute Maximum Ratings
Parameter
Value
VCC DC Supply Voltage FB Input Voltage
VOVP-1V -0.3 to 7V
CS Input Voltage
-0.3 to 7V
PRT Input Voltage
-0.3 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.
OB2283 X
X
High Performance Current Mode PWM Controller
Package
Package Pb-free
M:SOT23-6 P:Pb-free
Marking Information
83YWW S . ZZZ
©On-Bright Electronics
Y:Year Code WW:Week Code(01-52) s: Internal code ZZZ: Lot code
Confidential -2-
Preliminary Datasheet OB_DOC_DS_228300
OB2283
High Performance Current Mode PWM Controller
TERMINAL ASSIGNMENTS
Pin Name VCC CS Gate GND
PRT
FB
I/O Description
P Power Supply
I Current sense input
O Totem-pole gate driver output for power MOSFET
P Ground
Dual functions pin. Connecting a NTC resistor to ground for OTP detection.
I
Connecting a resistor from Vaux can adjust OVP trigger voltage. If both OTP and OVP are needed, a diode should be connected between PRT pin and the NTC
resistor.
I
Feedback input pin. The PWM duty cycle is determined by voltage level into this pin and the current-sense signal at Pin CS.
©On-Bright Electronics
Confidential -3-
Preliminary Datasheet OB_DOC_DS_228300
FUNCTIONAL BLOCK DIAGRAM
OB2283
High Performance Current Mode PWM Controller
OVP
OVP
SQ R
Logic Control
Soft Driver
UVLO
Vref& Iref
GND open
Temp sense EX OTP
AVDD
Internal blocks
OSC
Diode short
OLP
OCP Comparator
PK/Green/ Burst
PWM Comparator
Timer
OTP
OVP
Latch
EX OVP
Diode short
Diode short
compSelonpseation Vocp
OLP
LEB AVDD
©On-Bright Electronics
Confidential -4-
Preliminary Datasheet OB_DOC_DS_228300
OB2283
High Performance Current Mode PWM Controller
ELECTRICAL CHARACTE.