Product Specification Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback SG6849 FEATURES Linearly Decreasing PWM Frequency Green-Mode under Light-Load and Zero-Load Conditions Constant Voltage (CV) and Constant Current (CC) No Secondary Feedback Low Startup Current (5uA) Low Operating Current (3.6mA) Leading-Edge Blanking Constant Power Limit Universal AC Input Range Synchronized Slope Compensation 150°C OTP Sensor with Hysteresis VDD Over Voltage Clamping Cycle-by-Cycle Current Limiting Under Voltage Lockout (UVLO) Fixed PWM Frequency (65kHz/100kHz) Gate Output Maximum Voltage Clamped at 16.7V Small SOT-26 Package APPLICATIONS Low-power flyback power converters, such as Battery chargers for cellular phones, cordless phones, PDAs, digital cameras, and power tools. Power adapters for ink jet printers, video game consoles, and portable audio players. Open-frame SMPS for TV/DVD standby and other auxiliary supplies, home appliances, consumer electronics, and PC 5V standby-power. Replacements for linear transformers and RCC SMPS. DESCRIPTION This highly integrated PWM controller provides several features to enhance the performance of low power flyback converters. To minimize standby power consumption, the proprietary green-mode function provides off-time modulation to linearly decrease the switching frequency under light-load and zero-load conditions. This green-mode function enables the power supply to easily meet international power conservation requirements. The supply voltage VDD is also used for feedback compensation, to regulate the output voltage without requiring a conventional TL431 and a photo-coupler. Another advantage of the SG6849 is that the typical startup current is only 5uA, while the typical operating current can be as low as 3.6mA. A large startup resistance could be used to achieve even higher power conversion efficiency. Built-in synchronized slope compensation maintains the stability of peak current-mode control. Proprietary internal compensation ensures constant output power limiting over a universal range of AC input voltages, from 90VAC to 264VAC.The SG6849 provides many protection functions. Pulse-by-pulse current limiting ensures a constant output current, even if a short circuit occurs. Also, the internal protection circuit will disable PWM output, if VDD exceeds 22.7V. The gate output is clamped at 16.7V to protect the power MOS from over-voltage damage. The built-in over temperature protection (OTP) function will shutdown the controller at 150°C with a 20°C hysteresis. The SG6849 is designed to provide a low-cost total solution for flyback converters. It is available in a small footprint, 6-pin, SOT-26 package. TYPICAL IC APPLICATION V IN DO R IN D1 VDD G ATE C IN VO W AU X Q1 SE NSE GN D © System General Corp. Version 1.0(IRO33.0002.B3) CO RS -1- www.sg.com.tw Dec.29, 2003 Product Specification SG6849 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback MARKING INFORMATION PIN CONFIGURATION SOT-26 M: Mask Version X: B= SG6849-65T MXYWW C= SG6849-100T Y: Year 1 GND 1 6 GATE FB 2 5 VDD NC 3 4 SENSE WW: Work Week 8 DIP-8 ZZZ: 65 or 100 XXXXXXX: Wafer Lot SG6849-ZZZD YY: Year XXXXXXXYYWWV WW: Week V: Assembly Location 1 GATE 1 8 GND VDD 2 7 FB NC 3 6 NC SENSE 4 5 NC ORDERING INFORMATION Part Number PWM Frequency Package SG6849-65T 65kHz 6-Pin SOT-26 SG6849-100T 100kHz 6-Pin SOT-26 SG6849-65D 65kHz 8-pin DIP-8 SG6849-100D 100kHz 8-pin DIP-8 PIN DESCRIPTIONS Name Pin No. Type DIP-8 SOT-26 Function GATE 1 6 Driver Output The totem-pole output driver to drive the power MOSFET. VDD 2 5 Supply NC 3 NA Power supply. NC pin. Current sense. It senses the voltage across a sensed resistor. To provide over-current SENSE 4 4 NC 5 3 NC 6 NA Analog Input protection, PWM output is disabled if the voltage exceeds an internal threshold. This pin also provides current information for current-mode control. NC pin. NC pin. Feedback. The FB pin provides feedback information to the internal PWM comparator. FB 7 2 Analog Input This feedback is used to control the duty cycle. When no feedback is provided, this pin is GND 8 1 Supply left open. © System General Corp. Version 1.0(IRO33.0002.B3) Ground. -2- www.sg.com.tw Dec.29, 2003 Product Specification SG6849 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback BLOCK DIAGRAM GND 8(1) VDD OTP SENSE Internal Supply OSC Driver S R VDD 2(5) Q PWM Comp VDD Power Limiter Blanking Circuit Slope Compensation UVLO OCP Comp 17V/8V 1(6) GATE 4(4) SENSE 4.5V Σ Green Mode Controller VDD VDDZ 7(2) FB DIP-8(SOT-26) © System General Corp. Version 1.0(IRO33.0002.B3) -3- www.sg.com.tw Dec.29, 2003 Product Specification SG6849 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback ABSOLUTE MAXIMUM RATINGS Symbol Parameter VDD Value Unit DC Supply Voltage* 25 V Zener Clamp 30 V Zener Current 10 mA VFB FB Pin Input Voltage -0.3 to 7 V VSENSE Sense Pin Input Voltage -0.3 to 7 V PD Power Dissipation 300 mW RθJA Thermal Resistance (Junction to Air) RθJC Thermal Resistance (Junction to Case) SOT-26 243.3 DIP-8 113.0 SOT-26 115 DIP-8 67.1 °C/W °C/W TJ Operating Junction Temperature 150 °C TSTG Storage Temperature Range -55 to +150 °C TL Lead Temperature (Soldering) 20 sec SOT-26 220 10 sec DIP-8 260 °C ESD Capability, Human Body Model 3.0 kV ESD Capability, Machine Model 300 V *All voltage values, except differential voltages, are given with respect to the network ground terminal. OPERATING CONDITIONS Symbol Parameter Value Unit VDD DC Supply Voltage <22.7 V TA Operating Ambient Temperature -30 to +85 °C ELECTRICAL CHARACTERISTICS (VDD=15V, TA=25°C) Feedback Input Section Symbol Parameter IOZ Zero Duty-Cycle FB Input Current VFB Open Loop Voltage RFB Input Impedance VDDZ VDD Feedback Threshold Voltage* Test Condition Min. Typ. Max. Unit 1.15 1.4 mA 4.5 FB Input Current = 0.1mA V 2.4 kΩ FB Input Current = 0mA 20 22.7 25 V FB Input Current = 0.8mA 18 20 22 V *The feedback input is pulled by a transistor that is controlled by the VDD signal while VDD ≧ VDDZ. © System General Corp. Version 1.0(IRO33.0002.B3) -4- www.sg.com.tw Dec.29, 2003 Product Specification SG6849 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback Current Sense Section Symbol Parameter TPD Propagation Delay Test Condition Min. Typ. Max. Unit 100 ns VDD = 20V 0.84 0.89 0.94 V Current Limiting Valley Threshold Voltage for 65kHz VDD = 15V 0.72 0.77 0.82 V VDD = 10V 0.58 0.63 0.68 V VDD = 20V 0.76 0.81 0.86 V Current Limiting Valley Threshold Voltage for 100kHz VDD = 15V 0.65 0.70 0.75 V VDD = 10V 0.52 0.57 0.62 V VTH,VA TON VTH,FT VLIMIT Ramp TOFF 0.77V High-Line Low-Line Sense Sense Voltage VTH,VA Voltage 0V T1 T2 Oscillator Section Symbol Parameter FOSC SG6849–65 Frequency Test Condition Min. Typ. Max. Unit 60 65 70 kHz FOSC SG6849–100 Frequency 92 100 108 kHz FOSC-G-BK Green-Mode Burst Back Frequency* 20 25 30 kHz FOSC-G-OFF Green-Mode OFF Frequency* IFB-G-OFF Green-Mode OFF FB Input Current FDV VDD-TH-G 0 kHz 0.9 1.15 VDD-Low Threshold Voltage for Exiting Green-Mode VDD VDD VDD OFF OFF+1.0 OFF+1.5 OFF+2.0 Frequency Variation versus VDD Deviation VDD = 10 to 20V 1.4 mA 2 % V *Please see the “Green-Mode Burst Back (FOSC-G-BK) and Green-Mode OFF Frequency (FOSC-G-OFF) vs. VDD” curves. © System General Corp. Version 1.0(IRO33.0002.B3) -5- www.sg.com.tw Dec.29, 2003 Product Specification SG6849 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback Output Section Symbol Parameter DCYMAX Maximum Duty Cycle Test Condition Bnk Leading Edge Blanking Time VOL Output Voltage Low VDD = 15V, IO = 10mA VOH Output Voltage High VDD = 15V, IO = 10mA TR Rising Time VDD = 15V, CL = 1nF Min. Typ. Max. Unit 70 75 80 % 310 ns 1.5 8 V V 200 ns TF Falling Time VDD = 15V, CL = 1nF 80 VCLAMP Output Clamp Voltage VDD = 20V 16.7 18 ns Typ. Max. V Over Temperature Protection (OTP) Symbol Parameter Temp-Off Protection Junction Temperature Test Condition Temp-Restart Restart Junction Temperature Min. *1 *2 Unit 150 °C 130 °C *1 When activated, the output is disabled and the latch is turned off. *2 This is the threshold temperature for enabling the output again and resetting the latch, after over temperature protection has been activated. VDD Section Symbol Parameter VDD ON VDD OFF IDD ST Startup Current IDD OP Operating Supply Current VDD CLAMP Zener Diode Breakdown Voltage Min. Typ. Max. Unit Turn-On Threshold Voltage 16 17 18 V Turn-Off Threshold Voltage 7.5 8 8.5 V 5 30 uA 3.6 6 mA 28 30 V © System General Corp. Version 1.0(IRO33.0002.B3) Test Condition VDD = 15V VDD = 15V GATE is Open IDD = 10mA -6- www.sg.com.tw Dec.29, 2003 Product Specification SG6849 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback TYPICAL CHARACTERISTICS SG6849-65 Start-Up Current (I DD ST ) vs. Temperature Operating Supply Current (I DD OP) vs. Temperature 4.5 9.0 4.3 8.0 V DD =15.0V I DD OP (mA) ID D ST (uA) V DD =15.0V 4.0 7.0 6.0 3.8 5.0 3.5 4.0 3.3 3.0 3.0 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 T EMPERATURE (℃) 20 35 50 65 80 95 110 125 T EMPERATURE (℃) VFB Open Loop Voltage (VFB) vs. Temperature Maximum Duty Cycle (DCYMAX) vs. Temperature 5.0 80.0 VD D =15.0V 4.8 VD D =15.0V 78.0 V FB (V) DCY MAX (%) 4.6 4.4 4.2 76.0 74.0 72.0 70.0 4.0 -40 -30 -15 0 25 50 75 100 125 -40 -25 -10 5 T EMPERATURE (℃) 35 50 65 80 95 110 125 T EMPERAT URE (℃) Valley Threshold Voltage (VTH,VA) vs. Temperature Oscillator Frequency (F OSC) vs. Temperature 70.0 0.80 0.78 65.0 V DD =15.0V V TH ,VA (V) FOSC (kHz) 20 60.0 0.76 V D D =15.0V 0.74 55.0 0.72 50.0 0.70 -40 -25 -10 5 20 35 50 65 80 95 110 -40 125 © System General Corp. Version 1.0(IRO33.0002.B3) -25 -10 5 20 35 50 65 80 95 110 125 T EMPERAT URE (℃) TEMPERAT URE (℃) -7- www.sg.com.tw Dec.29, 2003 Product Specification SG6849 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback Turn-On Threshold Voltage (VDD ON) vs. Temperature Turn-Off Threshold Voltage (VDD OFF) vs. Temperature 9.00 18.0 17.5 8.50 VD D OFF (V) V DD ON (V) 17.0 16.5 8.00 16.0 7.50 15.5 15.0 7.00 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 T EMPERAT URE (℃) 20 35 50 65 80 95 110 125 TEMPERAT URE (℃ ) Green-Mode Burst Back(F OSC-G-BK) and Green-Mode OFF Frequency(F OSC-G-OFF) vs. VDD Output Voltage Low (VOL) vs. Temperature 30.0 0.40 FOSC -G- BK 25.0 0.30 FOSC (kHz) V OL (V) 20.0 0.20 15.0 10.0 0.10 5.0 FOSC- G-OFF 0.00 -40 -25 -10 5 20 35 50 65 80 95 110 125 0.0 8 TEMPERAT URE (℃) 8.5 9 9.5 10 VD D (V) Valley Threshold Voltage(VTH,VA) vs. VDD VLIMIT Ramp vs. Duty Cycle 1.00 1.10 0.90 V DD =15.0V 0.80 Vlimit (V) VTH,VA (V) 1.05 0.70 1.00 0.95 0.60 0.50 0.90 9 10 11 12 13 14 15 16 17 18 19 20 10 V D D (V) © System General Corp. Version 1.0(IRO33.0002.B3) 15 20 25 30 35 40 Duty Cycle (%) -8- www.sg.com.tw Dec.29, 2003 Product Specification SG6849 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback OPERATION DESCRIPTION Over Temperature Protection (OTP) SG6849 devices integrate many useful functions for low power switch mode power supplies. The following descriptions highlight the key features of the SG6849. The SG6849 has a built-in temperature sensing circuit to shut down PWM output once the junction temperature exceeds 150°C. While PWM output is shut down, the VDD voltage will gradually drop to the UVLO voltage. Some of the SG6849’s internal circuits will be shut down, and VDD will gradually start increasing again. When VDD reaches 17V, all the internal circuits, including the temperature sensing circuit, will start operating normally. If the junction temperature is still higher than 150°C, the PWM controller will be shut down immediately. This situation will continue until the temperature drops below 130°C. The PWM output will then be turned back on. The temperature hysteresis window for the OTP circuit is 20°C. Startup Current The required startup current is only 5uA. This allows a high-resistance, low-wattage startup resistor to be used to supply the controller’s startup power. A 1.5 MΩ/0.25W startup resistor can be used over a wide input range (100V-240V AC) with very little power loss. Operating Current The operating current is normally 3.6mA. The low operating current results in higher efficiency and reduces the required VDD hold-up capacitance. A 10uF/25V VDD hold-up capacitor can be used over a wide input range (100V-240V AC) with very little power loss. Green Mode Operation The proprietary green-mode function provides off-time modulation to linearly decrease the switching frequency under light-load and zero-load conditions. The on-time is limited to provide better protection against brownouts and other abnormal conditions. This green-mode function dramatically reduces power consumption under light-load and zero-load conditions. Power supplies using the SG6849 can easily meet international restrictions regarding standby power-consumption. Constant Voltage (CV) and Constant Current (CC) without Feedback The SG6849 can tightly regulate the output voltage and provide over current protection without requiring secondary-side feedback signals. For improved CV and CC accuracy, the transformer leakage inductance should be reduced as much as possible. © System General Corp. Version 1.0(IRO33.0002.B3) VDD Over Voltage Clamping VDD over voltage clamping is built in to prevent damage from over-voltage conditions. When VDD exceeds 22.7V, PWM output is shut down. Over-voltage conditions may be caused by an open photo-coupler loop or a short circuit in the output. Oscillator Operation The oscillation frequency is fixed at 65kHz for the SG6849-65, and at 100kHz for the SG6849-100. Leading Edge Blanking Each time the power MOSFET is switched on, a turn-on spike will inevitably occur at the sense-resistor. To avoid premature termination of the switching pulse, a 310ns leading-edge blanking time is built in. Conventional RC filtering is not necessary. During this blanking period, the current-limit comparator is disabled, and it cannot switch off the gate drive. Constant Output Power Limit When the SENSE voltage across the sense resistor RS reaches the threshold voltage (around 1.0V), the output GATE drive will be turned off following a small -9- www.sg.com.tw Dec.29, 2003 Product Specification Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback propagation delay TPD. This propagation delay will introduce an additional current proportional to TPD*VIN/LP. The propagation delay is nearly constant regardless of the input line voltage VIN. Higher input line voltages will result in larger additional currents. Thus, under high input-line voltages the output power limit will be higher than under low input-line voltages. Over a wide range of AC input voltages, the variation can be significant. To compensate for this, the threshold voltage is adjusted by adding a positive ramp. This ramp signal can vary from 0.77V to 1.05V for SG6849-65 and 0.70 to 1.03V for SG6849-100, and it flattens out at 1.05V and 1.03V respectively. A smaller threshold voltage forces the output GATE drive to terminate earlier, thus reducing total PWM turn-on time and making the output power equal to that of the low line input. This proprietary internal compensation feature ensures a constant output power limit over a wide range of AC input voltages (90VAC to 264VAC). SG6849 Gate Output The SG6849 BiCMOS output stage is a fast totem pole gate driver. Cross-conduction has been avoided to minimize heat dissipation, increase efficiency, and enhance reliability. The output driver is clamped by an internal 16.7V Zener diode in order to protect the power MOSFET transistors against any harmful over-voltage gate signals. Slope Compensation The sensed voltage across the current sense resistor is used for current mode control and pulse-by-pulse current limiting. The built-in slope compensation function improves power supply stability. Furthermore, it prevents sub-harmonic oscillations that normally would occur because of peak current mode control. A positively sloped, synchronized ramp is activated by the SG6849 with every switching cycle. The slope of the ramp is Under Voltage Lockout (UVLO) The turn-on/turn-off thresholds of the SG6849 are fixed internally at 17V/8V. To enable the SG6849 during startup, the hold-up capacitor must first be charged to 17V through the startup resistor. The hold-up capacitor will continue to supply VDD before energy can be delivered from the auxiliary winding of the main transformer. VDD must not drop below 8V during this startup process. This UVLO hysteresis window ensures that the hold-up capacitor can adequately supply VDD during startup. © System General Corp. Version 1.0(IRO33.0002.B3) 0.33 × Duty . Duty (max) Noise Immunity Noise from the current sense or the control signal may cause significant pulse width jitter, particularly in continuous-conduction mode. Slope compensation helps alleviate this problem. Good placement and layout practices should be followed. The designer should avoid long PCB traces and component leads. Compensation and filter components should be located near the SG6849. Finally, increasing the power-MOS gate resistance is advised. - 10 - www.sg.com.tw Dec.29, 2003 Product Specification SG6849 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback REFERENCE CIRCUIT 3W Flyback 5V/0.6A Circuit, without Secondary-Side Feedback F1 L1 1 1 L CX1 2 BD1 2 - + 4 + C1 R1 C2 C3 R3 R5 R4 D4 T1 10 2 1 1 L2 VO 2 R2 9 D1 R10 22 8 5 2 3 GATE FB VDD NC SENSE + D5 + C9 Q1 1 2 GND 6 R7 5 3 1 U4 C7 C8 1 3 1 N 1,2 7 4 3,4 GND SG6849 R6 R8 D2 1 2 CY1 + C4 BOM Symbol Component Symbol Component BD1 BD 1A/500V L1 20mH 6*8mm CX1 (Option) YC 472pF/400V (Y1) L2 10uH 6mm CY1 (Option) YC 102pF/400V (Y1) Q1 MOSFET 1A/600V C2 EC 10uF/400V 105℃ R1,R2 R 750kΩ 1206 C1 CC 103pF/500V R3,R4 R 47kΩ 1206 C3 CC 1000pF/500V R5 R 47Ω 1206 C4 EC 10uF/50V R6 R 4.7Ω 1206 R 100Ω 0805 C7 CC 102pF/100V 1206 R7 C8 (Option) EC 470uF/10V 105℃ R8 C9 EC 220uF/10V 105℃ R10 R 10Ω 1206 (Option) R 10Ω 1206 D1 Diode FRI07 T1 EE-16 D2 Diode FR102 U4 IC SG6849 (Green PWM IC) D4 D5 F1 Diode SB360 (Option) ZD 6.8V 0.5W R 1Ω/0.5W © System General Corp. Version 1.0(IRO33.0002.B3) - 11 - www.sg.com.tw Dec.29, 2003 Product Specification SG6849 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback 3W Flyback 5V/0.6A Circuit, with Secondary-Side Feedback F1 L1 1 1 2 - N 2 BD1 + 4 + + C1 C3 R3 R5 R4 C2 T1 10 2 1,2 D4 1 L2 1 Vo 2 3 1 R1 9 D1 R10 22 R7 C7 8 5 1 L + C8 + C9 D5 Q1 3 2 1 7 GND 3,4 R6 1 2 3 C6 U1 SG6849 GND FB NC GATE VDD SENSE R2 6 R8 5 4 D2 1 2 + C4 R11 U2 4 1 3 2 R13 3 R14 C10 U3 CY1 1 2 R12 BOM Symbol Component Symbol Component BD1 (Reference only) DI106 1A/600V L2 10uH 6mm CY1 (Option) YC 102p/400V Q1 MOSFET 1A/600V C2 10uF/400V 10Φ*16mm 105℃ R1,R2 750k 1206 C1 103p/500V (0.01uF/500V) R4,R3 47k/1206 C3 1000p/500V CER R5 47 1206 C4 10u/50V 5mm R6 3.7 1206 C6 472p 0805 R7 100 0805 C7 102p/100V 1206 R10 10 1206 C8 470u/10V 8Φ*11.5mm 105℃ R8 5 1206 C9 470u/10V 8Φ*11.5mm 105℃ R11 100 1/8W C10 222p 0805 R12 33k 0805 D1 FR107 R13 33k 1/8W D2 FR102 R14 4.7k 0805 D4 SB360 (3A/60V; Schottky) T1 EE-16 D5 ZD/6.8V 0.5W U1 SG6849 (Green PWM IC) F1 1Ω1/2W Resistor U2 PC817 L1 20mH 6*8mm U3 TL431 DI106 1A/600V L2 10uH 6mm BD1 (Option) (Reference only) © System General Corp. Version 1.0(IRO33.0002.B3) - 12 - www.sg.com.tw Dec.29, 2003 Product Specification Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback SG6849 PACKAGE INFORMATION The SOT-26 Package D Detail A b 4 1 e 3 E E1 6 c R1 R θ A A2 1 L2 e1 L A1 θ L1 θ 1 Detail A Dimensions: Symbol A A1 A2 b c D E E1 e e1 L L1 L2 R R1 θ˚ θ1˚ Millimeters Min. 0.90 0.30 0.08 0.30 0.10 0.10 0˚ 5˚ © System General Corp. Version 1.0(IRO33.0002.B3) Inches Typ. Max. 1.15 1.45 0.15 1.30 0.50 0.22 2.90 2.80 1.60 0.95 1.90 0.45 0.60 0.25 4˚ 10˚ Min. 0.036 0.011 0.003 0.60 0.020 0.25 8˚ 15˚ 0.004 0.004 0˚ 5˚ - 13 - Typ. Max. 0.045 0.057 0.006 0.051 0.020 0.009 0.114 0.110 0.063 0.037 0.075 0.018 0.024 0.010 4˚ 10˚ 0.24 0.25 8˚ 15˚ www.sg.com.tw Dec.29, 2003 Product Specification SG6849 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback The DIP-8 Package D Θ° 5 E1 8 B A A2 4 A1 1 e E L b1 b e Dimensions: Symbol A A1 A2 b b1 D E E1 e L eB θ˚ Millimeter Min. Typ. Inch Min. Max. Typ. 5.334 0.381 3.175 9.017 6.223 2.921 8.509 0 © System General Corp. Version 1.0(IRO33.0002.B3) 3.302 1.524 0.457 9.271 7.620 6.350 2.540 3.302 9.017 7 Max. 0.210 3.429 0.015 0.125 10.160 0.355 6.477 0.245 3.810 9.525 15 0.115 0.335 0 - 14 - 0.130 0.060 0.018 0.365 0.300 0.250 0.100 0.130 0.355 7 0.135 0.400 0.255 0.150 0.375 15 www.sg.com.tw Dec.29, 2003 Product Specification Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback SG6849 DISCLAIMERS LIFE SUPPORT System General’s products are not designed to be used as components in devices intended to support or sustain human life. Use of System General’s products in components intended for surgical implant into the body, or other applications in which the failure of System General’s products could create a situation where personal death or injury may occur, is not authorized without the express written approval of System General’s Chief Executive Officer. System General will not be held liable for any damages or claims resulting from the use of its products in medical applications. MILITARY System General's products are not designed for use in military applications. Use of System General’s products in military applications is not authorized without the express written approval of System General’s Chief Executive Officer. System General will not be held liable for any damages or claims resulting from the use of its products in military applications. RIGHT TO MAKE CHANGES System General reserves the right to change this document and/or this product without notice. Customers are advised to consult their System General sales representative before ordering. © System General Corp. Version 1.0(IRO33.0002.B3) - 15 - www.sg.com.tw Dec.29, 2003