Document
OB2358L
Current Mode PWM Power Switch Frequency Shuffling
Product Specification
GENERAL DESCRIPTION
OB2358L combines a dedicated current mode
PWM controller with a high voltage power
MOSFET. It is optimized for high performance, low
standby power, and cost effective off-line flyback
converter applications in sub 27W range.
OB2358L offers complete protection coverage
with automatic self-recovery feature including
Cycle-by-Cycle current limiting (OCP), over load
protection (OLP), over temperature protection
(OTP), over voltage protection and VDD under
voltage lockout (UVLO).
Excellent EMI
performance is achieved with On-Bright
proprietary frequency shuffling technique together
with soft switching control at the totem pole gate
drive output.
The tone energy at below 20KHZ is minimized in
the design and audio noise is eliminated during
operation.
OB2358L is offered in DIP8 package.
APPLICATIONS
Offline AC/DC flyback converter for ■ AC/DC adapter ■ PDA power supplies ■ Digital Cameras and Camcorder Adapter ■ VCR, SVR, STB, DVD&DVCD Player SMPS ■ Set-Top Box Power ■ Auxiliary Power Supply for PC and Server ■ Open-frame SMPS
TYPICAL APPLICATION
FEATURES
■ Power on Soft Start Reducing MOSFET Vds Stress
■ Frequency shuffling for EMI ■ Extended Burst Mode Control For Improved
Efficiency and Minimum Standby Power Design ■ Audio Noise Free Operation ■ Fixed 50KHZ Switching Frequency ■ Internal Synchronized Slope Compensation ■ Low VDD Startup Current and Low Operating Current ■ Leading Edge Blanking on Current Sense Input ■ Good Protection Coverage With Auto SelfRecovery o VDD Under Voltage Lockout with Hysteresis
(UVLO) o Over Temperature Protection (OTP) o On-Bright Proprietary Line Input
Compensated Cycle-by-Cycle Over-current Threshold Setting For Constant Output Power Limiting Over Universal Input Voltage Range. o Overload Protection (OLP). o Over voltage Protection(OVP)
Output Power Table
Product OB2358L
230VAC±15% Open Frame1
27W
85-265VAC Open Frame1
16W
Notes: 1. Maximum practical continuous power in an open frame design with sufficient drain pattern as a heat sink, at 50℃
ambient. Higher output power is possible with extra added heat sink or air circulation to reduce thermal resistance.
©On-Bright Electronics
Confidential -1-
Datasheet OB_DOC_DS_2358LA1
OB2358L
Current Mode PWM Power Switch Frequency Shuffling
GENERAL INFORMATION
Pin Configuration The OB2358L is offered in DIP8 package as shown below.
Ordering Information Part Number Description OB2358LAP DIP8, Pb-free
Package Dissipation Rating
Package DIP8
RθJA (℃/W) 75
Note: Drain Pin Connected to 100mm2 PCB copper clad.
Absolute Maximum Ratings
Parameter
Drain Voltage (off state)
VDD Voltage
VDD-G Input Voltage
FB Input Voltage
Sense Input Voltage
Maximum Operating Junction
Temperature TJ
Min/Max
Storage
Temperature Tstg
Lead
Temperature
(Soldering, 10secs)
Value -0.3V to BVdss -0.3V to 30 V -0.3V to 30 V -0.3 to 7V -0.3 to 7V
150℃
-55 to 150℃
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
©On-Bright Electronics
Confidential -2-
Datasheet OB_DOC_DS_2358LA1
OB2358L
Current Mode PWM Power Switch Frequency Shuffling
TERMINAL ASSIGNMENTS
Pin Name GND
FB
VDD-G SENSE VDD
Drain
I/O Description
P Ground
I
Feedback input pin. The PWM duty cycle is determined by voltage level into this pin and the current-sense signal at Pin 4.
P Internal Gate Driver Power Supply
I Current sense input
P IC DC power supply Input
O
HV MOSFET Drain Pin. The Drain pin is connected to the primary lead of the transformer
BLOCK DIAGRAM
VDD 2 Internal supply
5V
RQ S
UVLO POR
OVP
Burst mode
RCeuferrreenntce OTP
Soft Driver
VDD_G 1
Drain 5/6
Power MOSFET
OSC
Extended
Burst mode
CPL Vth
Soft Start
OCP
Slope
compensation
SENSE 4
LEB
5.7V
PWM Comparator
50ms
OLP
7/8 GND
R FB 3
R
©On-Bright Electronics
Confidential -3-
Datasheet OB_DOC_DS_2358LA1
OB2358L
Current Mode PWM Power Switch Frequency Shuffling
ELECTRICAL CHARACTERISTICS
(TA = 25℃, VDD=16V, unless otherwise noted)
Symbol
Parameter
Test Conditions
Min Typ Max Unit
Supply Voltage (VDD)
Istartup
VDD Start Current
I_VDD_Operation
Operation Current
up VDD=11V,Measure Leakage current into VDD
VFB=3V
5 20 1.6
uA mA
UVLO(ON)
VDD
Under
Voltage Lockout
Enter
5.8 6.8 7.8 V
UVLO(OFF)
VDD
Under
Voltage Lockout
Exit (Recovery)
11.5 12.5 13.5 V
OVP(ON)
Over
voltage
protection voltage
CS=0V,FB=3V Ramp up VDD until gate clock is off
22.0
23.5
25.0
V
Feedback Input Section(FB Pin)
VFB_Open
VFB Open Loop Voltage
IFB_Short
FB pin short circuit current
Short FB pi.