Product Specification SGP400 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback FEATURES 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 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. The typical start-up current is only 8µA, while the typical operating current can be as low as 3.6mA. A large start-up resistance could be used to achieve even higher power conversion efficiency. SGP400 integrates a frequency hopping function, which helps reduce EMI emission of a power supply with minimum line filters. 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. Pulse-by-pulse current limiting ensures a constant output current, even if a short-circuit occurs. Also, the internal protection circuit disables 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 shuts down the controller at 140°C with a 30°C hysteresis. The SGP400, designed to provide a low-cost total solution for flyback converters, is available in a small footprint, 6-pin, SOT-26 package. Linearly decreasing PWM frequency Green-mode under light-load and zero-load conditions Constant voltage (CV) and constant current (CC) No secondary feedback Low start-up current (8µA) Low operating current (3.6mA) Leading-edge blanking Constant power limit Universal AC input range Synchronized slope compensation 140°C OTP sensor with hysteresis VDD over-voltage clamping Cycle-by-cycle current limiting Under-voltage lockout (UVLO) Fixed PWM frequency with hopping Gate output maximum voltage clamped at 17V 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 TYPICAL APPLICATION V IN DO R IN D1 CO W AUX VDD G ATE C IN Q1 SE N SE GN D © System General Corp. Version 1.0.1 (IAO33.0084.B0) VO RS -1- www.sg.com.tw • www.fairchildsemi.com September 24, 2007 Product Specification SGP400 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback MARKING INFORMATION PIN CONFIGURATION SOT-26 XXX: AAK=SGP400; : Lead Free M: Mask Version W: Week code A~Z=W1~W26 A~Z=W27~W52 XXXMW SGP400DP XXXXXXXXYWWV GATE GND VDD FB N.C. D: D=DIP P: Z=Lead free Null=Regular package XXXXXXXX: Wafer Lot Y: Year WW: Week V: Assembly Location SENSE DIP-8 GND GATE FB VDD N.C. N.C. SENSE N.C. ORDERING INFORMATION Part Number PWM Frequency Pb-Free Package SGP400TZ 65KHz 6-Pin SOT-26 SGP400DZ 65KHz 8-Pin DIP-8 PIN DESCRIPTIONS Name Pin No. DIP-8 SOT-26 Type Function GATE 1 6 Driver Output The totem-pole output driver to drive the power MOSFET. VDD 2 5 Supply NC 3 NA SENSE 4 4 NC 5 3 NC 6 NA Power supply. NC pin. Current sense. It senses the voltage across a sensed resistor. To provide over-current 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. FB 7 2 Feedback. The FB pin provides feedback information to the internal PWM comparator. Analog Input This feedback is used to control the duty cycle. When no feedback is provided, this pin is left open. GND 8 1 Supply © System General Corp. Version 1.0.1 (IAO33.0084.B0) Ground. -2- www.sg.com.tw • www.fairchildsemi.com September 24, 2007 Product Specification Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback SGP400 BLOCK DIAGRAM © System General Corp. Version 1.0.1 (IAO33.0084.B0) -3- www.sg.com.tw • www.fairchildsemi.com September 24, 2007 Product Specification SGP400 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit VVDD DC Supply Voltage* 30 V VFB FB Pin Input Voltage -0.3 to 7.0 V VSENSE Sense Pin Input Voltage -0.3 to 7 PD Power Dissipation (TA=85°C) RθJA Thermal Resistance (Junction-to-Air)** RθJC Thermal Resistance (Junction-to-Case)** V SOT-26 247 DIP-8 478 SOT-26 263.3 135.7 °C/W 119.6 67.1 °C/W DIP-8 SOT-26 DIP-8 mW °C TJ Operating Junction Temperature -40 to +125 TSTG Storage Temperature Range -55 to +150 °C TL Lead Temperature (Wave Soldering or Infrared, 10 Seconds) 260 °C ESD Electrostatic Discharge Capability, Human Body Model 4.0 KV Electrostatic Discharge Capability, Machine Model 200 V * All voltage values, except differential voltages, are given with respect to the network ground terminal. * Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. ** Thermal resistance •JA test board size: SOT 18×12×1.6mm/FR4; DIP 40×35×1.6mm/FR4. RECOMMENDED OPERATING CONDITIONS Symbol Parameter VDD DC Supply Voltage TA Operating Ambient Temperature With Secondary Feedback Without Secondary Feedback Value Unit <20 V <22.7 V -20 to +85 °C * For proper operation. ELECTRICAL CHARACTERISTICS (VDD=15V, TA=25°C, unless noted) VDD Section Symbol Parameter VDD-ON Turn-On Threshold Voltage Test Condition VDD-OFF Turn-Off Threshold Voltage IDD-ST Start-up Current VDD=VDD-ON-0.1V IDD-OP Operating Supply Current VDD=15V, CL=1nF VDD-G OFF Min. Typ. Max. Unit 16 17 18 V 7.5 8.0 8.5 V 8 20 µA 3.6 4.6 mA VDD-OFF+ 1.2 VDD Low-threshold Voltage to Exit Green-off Mode V Feedback Input Section Symbol Parameter AV Input-Voltage to Current-Sense Attenuation VFB-OPEN Open-Loop Voltage ZFB Input Impedance VDD-FB VDD Feedback Threshold Voltage* Test Condition Min. Typ. Max. 2/5 V/V 4.5 IFB=0.1mA to 0.2mA Unit V 2.4 KΩ FB is Open 20.7 22.7 24.7 V IFB=0.4mA 18.4 20.4 22.4 V * The feedback input is pulled by a transistor controlled by the VDD signal while VDD ≥ VDDZ. © System General Corp. Version 1.0.1 (IAO33.0084.B0) -4- www.sg.com.tw • www.fairchildsemi.com September 24, 2007 Product Specification SGP400 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback Current Sense Section Symbol Parameter tPD Propagation Delay Test Condition VSTHVA Current Limiting Valley Threshold Voltage VSTHFL Current Limiting Flat Threshold Voltage tLEB Leading-Edge Blanking Time Min. Typ. Max. Unit 100 150 ns VDD=18V 0.84 V VDD=15V 0.76 V VDD=10V 0.62 V VDD=18V 0.98 V VDD=15V 0.88 V VDD=10V 0.71 210 V 310 410 ns TOFF TON VSTHFL VLIMIT Ramp VSTHVA High-Line Low-Line Sense Sense Voltage Voltage 0V T1 T2 Oscillator Section Symbol Parameter Min. Typ. Max. Center Frequency Test Condition 62 65 68 Hopping Range ±4.1 ±4.6 ±5.1 Unit FOSC Frequency tHOP Hopping Period 4.1 4.0 5.1 ms FOSC-G Green-Mode Frequency 19.5 22.0 24.5 KHz VFB-N Green-Mode Entry FB Voltage 2.4 2.6 2.8 V VFB-G Green-Mode Ending FB Voltage SG Green-Mode Modulation Slope 100 Hz/mV FDV Frequency Variation vs. VDD Deviation VDD=10 to 20V 2 % FDT Frequency Variation vs. Temperature Deviation TA=-20 to 85°C 5.0 % © System General Corp. Version 1.0.1 (IAO33.0084.B0) VFB-N-0.7 40 -5- 70 1.5 KHz V www.sg.com.tw • www.fairchildsemi.com September 24, 2007 Product Specification SGP400 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback Output Section Symbol Parameter DCYMAX Maximum Duty Cycle Test Condition Min. Typ. Max. Unit 70 75 80 VGATE-L GATE Low Voltage VDD=15V, IO=10mA % 1.5 VGATE-H GATE High Voltage VDD=15V, IO=-10mA 8 V tr GATE Rising Time VDD=15V, CL=1nF 150 250 ns V 200 tf GATE Falling Time VDD=15V, CL=1nF 70 90 110 ns VGATE-CLAMP GATE Output Clamping Voltage VDD=20V 16 17 18 V Test Condition Min. Typ. Max. Unit Over-Temperature Protection (OTP) Symbol Parameter Temp-OTP Protection Junction Temperature* 140 °C Temp-Restart Restart Junction Temperature** 110 °C * When activated, the output is disabled and the latch is turned off. ** The threshold temperature for enabling the output and resetting the latch after over-temperature protection has been activated. © System General Corp. Version 1.0.1 (IAO33.0084.B0) -6- www.sg.com.tw • www.fairchildsemi.com September 24, 2007 Product Specification SGP400 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback TYPICAL CHARACTERISTICS Turn-off Threshold Voltage (VDD-OFF) vs Temperature Turn-On Threashold Voltage (VDD-ON) vs Temperature 18.0 8.5 8.3 VDD-OFF (V) VDD-ON (V) 17.5 17.0 16.5 8.1 7.9 7.7 7.5 16.0 -40 -25 -10 5 20 35 50 65 80 95 110 -40 125 -25 -10 5 20 35 50 65 80 95 110 125 22 23 Temperature (℃ ) Temperature (℃) Startup Current (IDD-ST) vs VDD Operating Supply Current (IDD-OP) vs VDD 20 5 18 16 4 IDD-OP (mA) IDD-ST (uA) 14 12 10 8 6 4 3 2 1 2 0 0 10 11 12 13 14 15 16 17 11 12 13 14 15 16 VDD Startup Current (IDD-ST) vs Temperature 18 19 20 21 Operating Supply Current (IDD-OP) vs Temperature 20 3.5 3.0 IDD-OP (mA) 15 IDD-ST (uA) 17 VDD 10 5 2.5 2.0 1.5 1.0 0 -40 -25 -10 5 20 35 50 65 80 95 110 -40 125 © System General Corp. Version 1.0.1 (IAO33.0084.B0) -25 -10 5 20 35 50 65 80 95 110 125 Temperature (℃) Temperature (℃ ) -7- www.sg.com.tw • www.fairchildsemi.com September 24, 2007 Product Specification SGP400 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback Frequency (FOSC) vs Temperature Maximum Duty Cycle (DCYMAN) vs Temperature 80 68 78 DCYMAN (%) FOSC (KHz) 66 64 62 76 74 72 70 60 -40 -25 -10 5 20 35 50 65 80 95 110 -40 125 -25 -10 5 FB Pin Input Voltage (VFB) vs Temperature 35 50 65 80 95 110 125 110 125 Propagation Delay (tPD) vs Temperature 150 5.4 130 tPD (ns) 5.2 VFB (V) 20 Temperature (℃) Temperature (℃ ) 5.0 4.8 110 90 70 50 4.6 -40 -25 -10 5 20 35 50 65 80 95 110 -40 125 -25 -10 5 20 35 50 65 80 95 Temperature (℃) Temperature (℃) Current Limiting Valley Threshold Voltage (VSTHVA) vs Temperature 1.0 VDD=18V 0.8 VSTHVA (V) VDD=15V 0.6 VDD=10V 0.4 0.2 0.0 -40 -25 -10 5 20 35 50 65 80 95 110 125 Temperature (℃) © System General Corp. Version 1.0.1 (IAO33.0084.B0) -8- www.sg.com.tw • www.fairchildsemi.com September 24, 2007 Product Specification Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback SGP400 OPERATION DESCRIPTION SGP400 devices integrate many useful functions for low-power switch-mode power supplies. The following descriptions highlight key features of the SGP400. Start-up Current The required start-up current is only 8µA, which allows a high-resistance, low-wattage start-up resistor to be used to supply the controller’s start-up power. A 1.5MΩ/0.25W start-up 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 10µF/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 SGP400 can easily meet international restrictions regarding standby power consumption. Constant Voltage (CV), Constant Current (CC) without Feedback Over-Temperature Protection (OTP) The SGP400 has a built-in temperature sensing circuit to shut down PWM output if the junction temperature exceeds 140°C. While PWM output is shut down, the VDD voltage gradually drops to the UVLO voltage. Some of the internal circuits are shut down and VDD gradually starts increasing again. When VDD reaches 17V, all the internal circuits, including the temperature sensing circuit, start operating normally. If the junction temperature is still higher than 140°C, the PWM controller shuts down immediately. This situation continues until the temperature drops below 110°C. The PWM output is then turned back on. The temperature hysteresis window for the OTP circuit is 30°C. 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. Leading-Edge Blanking Each time the power MOSFET switches on, a spike occurs 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 the blanking period, the current-limit comparator is disabled and cannot switch off the gate drive. The SGP400 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 1.0.1 (IAO33.0084.B0) -9- www.sg.com.tw • www.fairchildsemi.com September 24, 2007 Product Specification Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback SGP400 Constant Output Power Limit Gate Output When the SENSE voltage across the sense resistor, RS, reaches the threshold voltage (around 1.0V), the output GATE drive is turned off after a small propagation delay tPD. This propagation delay introduces additional current, proportional to tPD•VIN/LP. The propagation delay is nearly constant, regardless of the input line voltage VIN. Higher input line voltages result in larger additional currents. Under high input-line voltages, the output power limit is higher than under low input-line voltages. The 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 17V Zener diode to protect the power MOSFET transistors against any harmful over-voltage gate signals. 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 (VLIMIT_RAMP). This ramp signal can vary from 0.77V to 1.05V and it flattens out at 1.05V. A smaller threshold voltage forces the output GATE drive to terminate earlier, 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). Under-voltage Lockout (UVLO) The turn-on/turn-off thresholds are fixed internally at 17V/8V. To enable the SGP400 during start-up, the hold-up capacitor must first be charged to 17V through the start-up resistor. The hold-up capacitor continues to supply VDD before energy can be delivered from the auxiliary winding of the main transformer. VDD must not drop below 8V during this start-up process. This UVLO hysteresis window ensures that the hold-up capacitor can adequately supply VDD during start-up. © System General Corp. Version 1.0.1 (IAO33.0084.B0) 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 and prevents sub-harmonic oscillations that normally would occur because of peak current mode control. A positively sloped, synchronized ramp is activated with every switching cycle. The slope of the ramp is: 0.33 × Duty Duty(max) (1) 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. Avoid long PCB traces and component leads. Compensation and filter components should be located near the SGP400. Finally, increasing the power-MOS gate resistance is advised. - 10 - www.sg.com.tw • www.fairchildsemi.com September 24, 2007 Product Specification SGP400 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 6 R7 D5 + C9 Q1 1 2 GND + 5 3 1 U4 C7 C8 1 3 1 N 1,2 7 4 GND 3,4 SG6849 SGP400 R6 R8 D2 1 2 CY1 + C4 BOM Symbol Component Symbol Component BD1 (Reference only) BD DI106 1A/600V F1 R 1Ω/0.5W CX1 (Option) YC 472pF/400V (Y1) L1 Inductor 20mH 6•8mm CY1 (Option) Inductor 10µH 6mm YC 102pF/400V (Y1) L2 C1 CC 0.01µF/500V Q1 MOSFET 1A/600V C2 EC 10µF/400V 105°C R1,R2 R 750kΩ/1206 C3 CC 1000pF/500V R3,R4 R 47kΩ/1206 C4 EC 10µF/50V R5 R 47Ω/1206 CC 102pF/100V 1206 R6 R 4.7Ω/0.5W C7 (Option) C8 EC 470µF/10V 105°C R7 R 100Ω/0805 C9 EC 220µF/10V 105°C R8 R 10Ω/1206 D1 Diode FRI07 R10 D2 Diode FR102 T1 Transformer EE-16 D4 Diode SB360 U4 IC SGP400 (Green PWM IC) D5 (Option) (Option) R 10Ω/1206 ZD 6.8V/0.5W © System General Corp. Version 1.0.1 (IAO33.0084.B0) - 11 - www.sg.com.tw • www.fairchildsemi.com September 24, 2007 Product Specification SGP400 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback 3W Flyback 5V/0.6A Circuit, with Secondary-Side Feedback F1 L1 2 + 2 - + 4 N C3 R3 R5 R4 + C1 C2 3 R1 T1 D4 10 1,2 2 L2 1 1 Vo 2 9 D1 R10 22 8 5 R7 C7 1 1 1 BD1 1 L + C8 D5 + C9 Q1 3 2 1 7 GND 3,4 R6 U1 SG6849 1 2 3 C6 GND GATE FB VDD NC SENSE R2 6 R8 5 1 D2 2 4 + C4 SGP400 R11 U2 4 1 3 2 R13 3 R14 C10 U3 CY1 1 2 R12 BOM Symbol BD1 CY1 Component (Reference only) BD DI106 1A/600V (Option) YC 102p/400V Symbol Component L2 Inductor 10µH 6mm Q1 MOSFET 1A/600V C1 CC 0.01µF/500V R1,R2 R 750kΩ/1206 C2 EC 10µF/400V 105°C R4,R3 R 47kΩ/1206 C3 CC 1000p/500V R5 R 47Ω/1206 C4 EC 10µ/50V R6 R 4.7Ω/0.5W C6 CC 472p/0805 R7 R 100Ω/0805 C7 CC 102p/100V 1206 R10 R 10Ω/1206 C8 EC 470µ/10V 105°C R8 R 10Ω/1206 C9 EC 470µ/10V 105°C R11 R 100Ω/ 1/8W C10 CC 222p/0805 R12 R 33kΩ/0805 D1 Diode FR107 R13 R 33kΩ/ 1/8W D2 Diode FR102 R14 R 4.7kΩ/0805 D4 Diode SB360 T1 Transformer EE-16 D5 U1 IC SGP400 (Green PWM IC) F1 (Option) ZD 6.8V/0.5W R 1Ω/0.5W Resistor U2 IC PC817 L1 Inductor 20mH 6*8mm U3 IC TL431 © System General Corp. Version 1.0.1 (IAO33.0084.B0) - 12 - www.sg.com.tw • www.fairchildsemi.com September 24, 2007 Product Specification Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback SGP400 PACKAGE INFORMATION 6 PINS-SOT (T) D Detail A b 4 1 e 3 E E1 6 c R1 R θ A A2 1 L2 e1 L θ A1 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 1.0.1 (IAO33.0084.B0) 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 • www.fairchildsemi.com September 24, 2007 Product Specification SGP400 Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback 8 PINS-DIP (D) D Θ¢X 5 E1 8 e B E A A1 A2 4 1 L b1 b e Dimensions: Symbol A A1 A2 b b1 D E E1 e L eB θ˚ Millimeter Min. Inch Typ. Max. Min. Typ. 5.334 0.381 3.175 9.017 6.223 2.921 8.509 0 © System General Corp. Version 1.0.1 (IAO33.0084.B0) 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 • www.fairchildsemi.com September 24, 2007 Product Specification Low-Power Green-Mode PWM Flyback Power Controller without Secondary Feedback © System General Corp. Version 1.0.1 (IAO33.0084.B0) - 15 - SGP400 www.sg.com.tw • www.fairchildsemi.com September 24, 2007