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RS2258
Second‐Side Regulation Current Mode PWM Power Switcher
General Description
RS2258 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.
RS2258 offers complete protection coverage with automatic self‐recovery feature including Cycle‐by‐Cycle current limiting (OCP), over
load protection (OLP), VDD over voltage clamp and under voltage lockout (UVLO). Excellent EMI performance is achieved with Orister
proprietary frequency Jiggling 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. RS2258 is offered in DIP‐8 package.
Features
Applications
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Power on Soft Start Reducing MOSFET VDS Stress
Frequency Jiggling to reduce EMI
Burst Mode Control For Improved Efficiency and Minimum
Standby power Design
Audio Noise Free Operation
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Battery Charger
Digital Cameras and camcorder Adaptor
PDA power supplies
VCR, SVR, STB, DVD & DVCD Player SMPS
Set‐Top Box (STB) Power
Auxiliary Power Supply for PC and Server
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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 Self‐Recovery
Open‐frame SMPS
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VDD Over Voltage Clamp and Under Voltage Lockout
with Hysteresis (UVLO)
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Line Input Compensated Cycle‐by‐Cycle Over‐current
Threshold Setting For Constant Output Power Limiting
Over Universal Input Voltage Range
Overload Protection (OLP)
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Over Voltage Protection (OVP)
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DIP‐8 Package
RoHS Compliant and 100% Lead (Pb)‐Free and Green (Halogen
Free with Commercial Standard)
Application Circuits
L1
C4
T1
VOUT
D1
D4
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+
2
4
R5
C5
C1
C2
R2
R3
AC IN
R1
C3
R6
C6
Np
Ns
D2
D3
Naux
GND
R9
U2
U1
VDDG
R7
4
3
1
2
GND
GND
DRAIN
VDD
FB
C8
R8
SENSE DRAIN
RS2258
D5
R4
RS431
R10
C7
DS‐RS2258‐09 May, 2010
www.Orister.com