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SF5928
High Precision Primary Side Regulation (PSR) CV/CC Power Switch
FEATURES
◆ Built-in 600V Power MOSFET
◆ Low Standby Power Under 30mW, Easily to
Pass Energy Star EPS2.0
◆ Primary Side Regulation (PSR) without TL431
and Opto-Coupler
◆ ± 5% Constant Current (CC) and Constant
Voltage (CV) Regulation at Universal AC Input
◆ Proprietary
Cable
Voltage
Drop
Compensation in CV Mode
◆ Compensate for Line Voltage Variation
◆ Compensate for Transformer Inductance
Tolerances
◆ Built-in Control Loop Compensation in CV
Mode
◆ All Pins Floating Protection
◆ PFM Control Eases EMI Design
◆ Cycle-by-Cycle Current Limiting
◆ Built-in Leading Edge Blanking (LEB)
◆ Built-in Soft Start
◆ Output Over Voltage Protection
◆ VDD OVP & Clamp
◆ VDD Under Voltage Lockout (UVLO)
APPLICATIONS
◆ Battery chargers for cellular phones, cordless
phones, PDA, digital cameras, etc ◆ Replaces linear transformer and RCC SMPS ◆ Small power adapter ◆ AC/DC LED lighting
TYPICAL APPLICATION
GENERAL DESCRIPTION
SF5928 is a high performance, highly integrated DCM (Discontinuous Conduction Mode) Primary Side Regulation (PSR) power switch for offline small power converter applications. SF5928 uses Pulse Frequency Modulation (PFM) control to improve efficiency and eases system EMI design. The IC dramatically lowers system cost by eliminating the opto-coupler and secondary control circuits. It also can provide very tight output voltage regulation (CV), in addition to output current control (CC) ideal for charging applications. SF5928 has Error Amplifier (EA) CV with built-in loop compensation network for CV control, which eliminates external compensation circuitry. It has built-in cable drop compensation function, which can provide excellent CV performance. The IC also has built-in soft start function to soften the stress on the MOSFET during power on period. Under light load conditions, the IC decreases switching frequency to achieve excellent regulation and high efficiency, yet meets the requirement for no-load consumption less than 30mW. SF5928 integrates functions and protections of Under Voltage Lockout (UVLO), VDD Over Voltage Protection (VDD OVP), Output Over Voltage Protection (Output OVP), Soft Start, Cycle-by-cycle Current Limiting (OCP), All Pins Floating Protection, VDD Clamping. SF5928 is available in DIP8 package.
AC IN
SF5928
1 VDD GND 8
2 NC GND 7
3 FB 4 CS
Drain 6 Drain 5
DC Out
© - 1 - _DS_5928_V1.0
Softwin swAides
Pin Configuration
VDD NC FB CS
18 DIP8
27 36 45
GND GND Drain Drain
SF5928
Ordering Information
Part Number
Top Mark
SF5928DP
SF5928DP
DIP8
Output Power Table(1) Part Number
SF5928
230VAC ± 15%(2) Adapter(3)
18W
Package
RoHs
Tape & Reel
85-265VAC Adapter(3)
13W
Note 1. The Max. output power is limited by junction temperature Note 2. 230VAC or 100/115VAC with doublers Note 3. Typical continuous power in a non-ventilated enclosed adapter with sufficient drain pattern as a heat
sink at 50 oC .