Product Specification SG5842A/JA Highly Integrated Green-Mode PWM Controller FEATURES Green-Mode PWM Controller Low Start-up Current (14µA) Low Operating Current (4mA) Programmable PWM Frequency with Hopping (5842JA) Peak-Current-Mode Control Cycle-by-Cycle Current Limiting Synchronized Slope Compensation Leading-Edge Blanking Constant Output Power Limit Totem Pole Output with Soft Driving VDD Over-Voltage Protection (OVP) Programmable Over-Temperature Protection (OTP) Internal Latch Circuit (OTP, OVP) Internal Open-Loop Protection VDD Under-Voltage Lockout (UVLO) GATE Output Maximum Voltage Clamp (18V) APPLICATIONS General-purpose switch mode power supplies and flyback power converters, including: Notebook Power Adapters Open-Frame SMPS To minimize standby power consumption, a proprietary green-mode function provides off-time modulation to continuously decrease the switching frequency at light-load conditions. To avoid acoustic-noise problem, the minimum PWM frequency set above 22KHz. This green-mode function enables the power supply to meet international power conservation requirements. To further reduce power consumption, SG5842A/JA is manufactured using the BiCMOS process. This allows a low start-up current, around 14µA, and an operating current of only 4mA. As a result, a large start-up resistance can be used. The SG5842A/JA built-in synchronized slope compensation achieves stable peak-current-mode control. SG5842JA integrates a frequency hopping function that helps reduce EMI emission of a power supply with minimum line filters. SG5842A/JA provides many protection functions. In addition to cycle-by-cycle current limiting, the internal open-loop protection circuit ensures safety should an open loop or output short-circuit failure occur. PWM output is disabled until VDD drops below the UVLO lower limit, then the controller starts again. As long as VDD exceeds about 24V, the internal OVP circuit is triggered. An external NTC thermistor can be applied for over-temperature protection. DESCRIPTION The highly integrated SG5842A/JA series of PWM controllers provides several features to enhance the performance of flyback converters. SG5842A/JA is available in an 8-pin DIP or SOP package. TYPICAL APPLICATION SG5842A/JA © System General Corp. Version 1.4.2 (IAO33.0026.B6) -1- www.sg.com.tw • www.fairchildsemi.com October 30, 2007 Product Specification SG5842A/JA Highly Integrated Green-Mode PWM Controller MARKING DIAGRAMS PIN CONFIGURATION H: J = with Frequency Hopping Null = without Frequency Hopping T: D = DIP, S = SOP P: Z = Lead Free Null = regular package XXXXXXXX: Wafer Lot Y: Year; WW: Week V: Assembly Location SG5842HATP XXXXXXXXYWWV GND GATE FB VDD VIN RI SENSE RT ORDERING INFORMATION Part Number OTP Latch OVP Latch Frequency Hopping Pb-Free Package SG5842JASZ Yes Yes Yes 8-Pin SOP SG5842JADZ Yes Yes Yes 8-Pin DIP SG5842ASZ (Preliminary) Yes Yes No 8-Pin SOP SG5842ADZ (Preliminary Yes Yes No 8-Pin DIP PIN DESCRIPTIONS Pin No. Symbol Function Description 1 GND Ground Ground. 2 FB Feedback The signal from the external compensation circuit is fed into this pin. The PWM duty cycle is determined in response to the signal from this pin and the current-sense signal from Pin 6. If FB voltage exceeds the threshold, the internal protection circuit disables PWM output after a predetermined delay time. 3 VIN Start-up Input For start-up, this pin is pulled high to the rectified line input via a resistor. Since the start-up current requirement of the SG5842A/JA is very small, a large start-up resistance can be used to minimize power loss. 4 RI Reference Setting A resistor connected from the RI pin to GND pin provides a constant current source. This determines the center PWM frequency. Increasing the resistance reduces PWM frequency. Using a 26KΩ resistor results in a 65KHz center PWM frequency. 5 RT Temperature Detection For over-temperature protection. An external NTC thermistor is connected from this pin to the GND pin. The impedance of the NTC decreases at high temperatures. Once the voltage of the RT pin drops below a fixed limit, PWM output is latched off. 6 SENSE Current Sense Current sense. The sensed voltage is used for peak-current-mode control and cycle-by-cycle current limiting. 7 VDD Power Supply Power supply. The internal protection circuit disables PWM output if VDD is over-voltage. 8 GATE Driver Output The totem-pole output driver for the power MOSFET, which is internally clamped below 18V. © System General Corp. Version 1.4.2 (IAO33.0026.B6) -2- www.sg.com.tw • www.fairchildsemi.com October 30, 2007 Product Specification SG5842A/JA Highly Integrated Green-Mode PWM Controller BLOCK DIAGRAM 5842JA only © System General Corp. Version 1.4.2 (IAO33.0026.B6) -3- www.sg.com.tw • www.fairchildsemi.com October 30, 2007 Product Specification SG5842A/JA Highly Integrated Green-Mode PWM Controller ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit VVDD Supply Voltage 30 V VVIN Input Terminal 30 V VFB Input Voltage to FB Pin -0.3 to 7.0 V VSENSE Input Voltage to SENSE Pin -0.3 to 7.0 V VRT Input Voltage to RT Pin -0.3 to 7.0 V VRI Input Voltage to RI Pin -0.3 to 7.0 V PD Power Dissipation (TA < 50°C ) RΘ JA Thermal Resistance (Junction-to-Air) DIP 800.0 SOP 400.0 DIP 82.5 SOP 141.0 mW °C/W TJ Operating Junction Temperature -40 to +125 TSTG Storage Temperature Range -55 to +150 °C °C TL Lead Temperature (Wave Soldering or Infrared, 10 Seconds) 260 °C VESD,HBM Electrostatic Discharge Capability, Human Body Model 3.0 KV VESD,MM Electrostatic Discharge Capability, Machine Model 250 V * All voltage values, except differential voltages, are given with respect to GND pin. * Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. RECOMMENDED OPERATING CONDITIONS Symbol Parameter Value Unit TA Operating Ambient Temperature -20 to +85 °C * For proper operation. ELECTRICAL CHARACTERISTICS VDD = 15v, TA = 25°C, unless otherwise noted. VDD Section Symbol Parameter VDD-OP Continuously Operating Voltage Test Condition Min. Typ. Max. Unit 20 V VDD-ON Start Threshold Voltage 15.5 16.5 17.5 V VDD-OFF Minimum Operation Voltage 9.5 10.5 11.5 V IDD-ST Start-up Current VDD=VDD-ON–0.16V 14 30 µA Operating Supply Current VDD=15V, RI=26KΩ, GATE=OPEN 4 5 mA 24.2 25.2 V IDD-OP VDD-OVP VDD Over-Voltage Protection tD-OVP VDD Over-Voltage Protection Debounce Time RI=26KΩ 23.2 IDD-H Holding Current After OVP/OTP Latch-up VDD=5V 40.0 52.5 65.0 µA Test Condition Min. Typ. Max. Unit 36.0 KΩ 100 µs RI Section Symbol Parameter RINOR RI Operating Range RIMAX Maximum RI Value for Protection 230 KΩ RIMIN Minimum RI Value for Protection 10 KΩ © System General Corp. Version 1.4.2 (IAO33.0026.B6) 15.5 -4- www.sg.com.tw • www.fairchildsemi.com October 30, 2007 Product Specification SG5842A/JA Highly Integrated Green-Mode PWM Controller Oscillator Section Symbol FOSC Parameter Normal PWM Frequency Test Condition Min. Typ. Max. Center Frequency RI=26KΩ 62 65 68 Hopping Range RI=26KΩ (5842JA only) ±3.7 ±4.2 ±4.7 Unit KHz tHOP Hopping Period RI=26KΩ (5842JA only) 3.9 4.4 4.9 FOSC-G Green-Mode Minimum Frequency RI=26KΩ 18 22 25 ms KHz FDV Frequency Variation vs. VDD Deviation VDD=11.5V to 20V 5 % FDT Frequency Variation vs. Temperature Deviation TA=-20 to 85°C 5 % Feedback Input Section Symbol Parameter Min. Typ. Max. Unit AV FB Input to Current Comparator Attenuation 1/4.5 1/4.0 1/3.5 V/V ZFB Input Impedance 4 VFB-OPEN Output High Voltage VFB-OLP FB Open-Loop Trigger Level tD-OLP FB Open-Loop Protection Delay Test Condition FB pin open 7 5.5 KΩ V 5.4 V RI=26KΩ 5.0 50 56 62 ms 1.9 2.1 2.3 VFB-N Green-Mode Entry FB Voltage RI=26KΩ VFB-G Green-Mode Ending FB Voltage RI=26KΩ VFB-N-0.5 V V Current Sense Section Symbol Parameter ZSENSE Input Impedance VSTHFL Current Limit Flatten Threshold Voltage Test Condition Min. Typ. Max. Unit 0.95 V 12 0.85 0.90 KΩ VSTHVA Current Limit Valley Threshold Voltage VSTHFL–VSTHVA 0.22 V DCYSAW Duty Cycle of SAW Limit Maximum Duty Cycle 45 % tPD Propagation Delay to GATE Output RI=26KΩ tLEB Leading-Edge Blanking Time RI=26KΩ © System General Corp. Version 1.4.2 (IAO33.0026.B6) -5- 200 150 200 ns 270 350 ns www.sg.com.tw • www.fairchildsemi.com October 30, 2007 Product Specification SG5842A/JA Highly Integrated Green-Mode PWM Controller GATE Section Symbol Parameter DCYMAX Maximum Duty Cycle Test Condition Min. Typ. Max. 60 65 70 VGATE-L Output Voltage Low % 1.5 V VGATE-H Output Voltage High VDD=12.5V, IO=-50mA 7.5 tr Rising Time VDD=15V, CL=1nF 150 250 350 ns tf Falling Time VDD=15V, CL=1nF 30 IO Peak Output Current VDD=15V, GATE=6V 230 50 90 ns VGATE-CLAMP Gate Output Clamping Voltage VDD=20V 18 19 V Unit VDD=15V, IO=50mA Unit V mA RT Section Symbol Parameter Test Condition Min. Typ. Max. IRT Output Current of RT Pin RI=26KΩ 67 70 73 µA VRTTH Over-Temperature Protection Threshold Voltage 1.015 1.050 1.085 V tD-OTP Over-Temperature Debounce 60 100 140 µs © System General Corp. Version 1.4.2 (IAO33.0026.B6) RI=26KΩ -6- www.sg.com.tw • www.fairchildsemi.com October 30, 2007 Product Specification SG5842A/JA Highly Integrated Green-Mode PWM Controller TYPICAL CHARACTERISTICS Start-up Current (I DD-S T ) vs Temperature 30 5.0 26 4.5 IDD-OP (m A) IDD-S T (uA) Operating Supply Current (I DD-OP ) vs Temperature 22 18 14 4.0 3.5 3.0 10 2.5 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 Temperature (℃) 20 35 50 65 80 95 110 125 95 110 125 95 110 125 Temperature (℃) Start Threshold Voltage (V DD-ON ) vs Temperature Operation Current (IDD-OP ) vs VDD Voltage 15 17.5 17.0 V DD-ON (V) IDD-OP (m A) 12 9 GATE = 1000pF 6 3 16.5 16.0 GATE = OPEN 15.5 0 12 13 14 15 16 17 18 19 20 21 22 23 -40 24 -25 -10 5 20 35 50 65 80 Tem perature (℃) VDD Voltage (V) PWM Frequency (Fosc) vs Temperature M in. Operating Voltage (V DD-OFF ) v s Tem perature 68 11.5 67 Fosc (Khz) V DD-OFF (V) 11.0 10.5 10.0 66 65 64 63 9.5 62 -40 -25 -10 5 20 35 50 65 80 95 110 125 Tem perature (℃) © System General Corp. Version 1.4.2 (IAO33.0026.B6) -40 -25 -10 5 20 35 50 65 80 Temperature (℃) -7- www.sg.com.tw • www.fairchildsemi.com October 30, 2007 Product Specification SG5842A/JA Highly Integrated Green-Mode PWM Controller Trigger Voltage for Over-temperature Protection (V RTTH ) vs Temperature Max. Duty Cycle (DCY MA X . ) vs Temperature 70 1.085 1.075 V (RTTH) (V) DCY MA X . (%) 68 66 64 62 1.065 1.055 1.045 1.035 1.025 1.015 60 -40 -25 -10 5 20 35 50 65 80 95 110 125 Tem perature (℃) -40 -25 -10 5 20 35 50 65 80 95 110 125 Temperature (℃) Output Current of RT pin (I RT ) vs Temperature 73 72 IRT (uA) 71 70 69 68 67 -40 -25 -10 5 20 35 50 65 80 95 110 125 Tem perature (℃) © System General Corp. Version 1.4.2 (IAO33.0026.B6) -8- www.sg.com.tw • www.fairchildsemi.com October 30, 2007 Product Specification SG5842A/JA Highly Integrated Green-Mode PWM Controller OPERATION DESCRIPTION Leading-Edge Blanking Start-up Current Each time the power MOSFET is switched on, a turn-on spike occurs at the sense-resistor. To avoid premature termination of the switching pulse, a leading-edge blanking time is built in. During this blanking period, the current-limit comparator is disabled and cannot switch off the gate drive. The typical start-up current is only 14µA, which allows a high-resistance, low-wattage start-up resistor to be used to minimize power loss. A 1.5MΩ, 0.25W, start-up resistor and a 10µF/25V VDD hold-up capacitor are sufficient for an AC/DC adapter with a universal input range. Under-Voltage Lockout (UVLO) Operating Current The required operating current has been reduced to 4mA. This results in higher efficiency and reduces the VDD hold-up capacitance requirement. Green-Mode Operation The proprietary green-mode function provides off-time modulation to continuously decrease the PWM frequency under light-load conditions. To avoid acoustic noise problems, the minimum PWM frequency is set above 22KHz. This green-mode function dramatically reduces power consumption under light-load and zero-load conditions. Power supplies using a SG5842A/JA controller can meet even the most restrictive international regulations regarding standby power consumption. Oscillator Operation A resistor connected from the RI pin to the GND pin generates a constant current source for the SG5842A/JA controller. This current is used to determine the center PWM frequency. Increasing the resistance reduces PWM frequency. Using a 26KΩ resistor, RI, results in a corresponding 65KHz PWM frequency. The relationship between RI and the switching frequency is: fPWM = 1690 RI (KΩ ) (KHz) ---------------------------- (1) The range of the PWM oscillation frequency is designed as 47KHz ~ 109KHz. The turn-on/turn-off thresholds are fixed internally at 16.5V/10.5V. To enable a SG5842A/JA controller during start-up, the hold-up capacitor must first be charged to 16.5V 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 10.5V during this start-up process. This UVLO hysteresis window ensures that the hold-up capacitor can adequately supply VDD during start-up. Gate Output / Soft Driving The SG5842A/JA 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 18V Zener diode to protect the power MOSFET transistors from any harmful over-voltage gate signals. A soft driving waveform is implemented to minimize EMI. Slope Compensation The sensed voltage across the current sense resistor is used for peak-current-mode control and cycle-by-cycle current limiting. The built-in slope compensation function improves power supply stability and prevents peak-current-mode control from causing sub-harmonic oscillations. Within every switching cycle, the SG5842A/JA controller produces a positively sloped, synchronized ramp signal. SG5842JA also integrates frequency hopping function internally. The frequency variation ranges from around 62KHz to 68KHz for a center frequency of 65KHz. The frequency hopping function helps reduce EMI emission of a power supply with minimum line filters. © System General Corp. Version 1.4.2 (IAO33.0026.B6) -9- www.sg.com.tw • www.fairchildsemi.com October 30, 2007 Product Specification SG5842A/JA Highly Integrated Green-Mode PWM Controller Constant Output Power Limit Protection Latch Circuit When the SENSE voltage, across the sense resistor RS, reaches the threshold voltage, around 0.85V, the output GATE drive is turned off after a small delay tPD. This delay introduces additional current, proportional to tPD • VIN / LP. Since the delay is nearly constant regardless of the input voltage VIN. Higher input voltage results in a larger additional current and the output power limit is also higher than under low input line voltage. To compensate this variation for a wide AC input range, a sawtooth power-limiter (saw limiter) is designed to solve the unequal power-limit problem. The saw limiter is designed as a positive ramp signal (VLIMIT_RAMP) and is fed to the inverting input of the OCP comparator. This results in a lower current limit at high-line inputs than at low-line inputs. For the SG5842A/JA family, the built-in latch function provides a versatile protection feature that does not require external components (see ordering information for a detailed description). To reset the latch circuit, disconnect the AC line voltage of the power supply. VDD Over-Voltage Protection Noise Immunity VDD over-voltage protection has been built in to prevent damage due to abnormal conditions. Once the VDD voltage is over than the VDD over-voltage protection voltage (VDD-OVP) and lasts for tD-OVP, the PWM pulses is latched off. The PWM pulses stay latched off until the user unplugs the power supply from the mains outlet. 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 SG5842A/JA. Finally, increasing the power-MOS gate resistance is advised. Limited Power Control Thermal Protection An external NTC thermistor can be connected from the RT pin to ground. A fixed current, IRT, is sourced from the RT pin. Because the impedance of the NTC decreases at high temperatures, when the voltage of the RT pin drops below 1.05V, PWM output is latched off. The RT pin output current is related to the PWM frequency programming resistor RI. The FB voltage increases every time the output of the power supply is shorted or over loaded. If the FB voltage remains higher than a built-in threshold longer than tD-OLP, PWM output is turned off. As PWM output is turned off, the supply voltage VDD begins decreasing. t D - OLP (ms) = 2 .154 × R I (K Ω ) ----------------- (2) When VDD goes below the turn-off threshold (eg, 10.5V) the controller is totally shut down. VDD is charged up to the turn-on threshold voltage of 16.5V through the start-up resistor until PWM output is restarted. This protection feature remains activated as long as the over-loading condition persists. This prevents the power supply from overheating due to over loading conditions. © System General Corp. Version 1.4.2 (IAO33.0026.B6) - 10 - www.sg.com.tw • www.fairchildsemi.com October 30, 2007 Product Specification SG5842A/JA Highly Integrated Green-Mode PWM Controller 2 REFERENCE CIRCUIT 4 C2 4 L3 1 2 Vo+ 2 C6 +C8 R2 R7 1 1 R5 D2 R6 2 2 R1 D3 1 C5 C7 + R4 3 1 3 1 3 1 + D1 R3 C3 2 2 3 C4 TR1 2 T1 1 1 L2 C1 VZ1 2 L1 2 4 1 2 1 2 3 Q1 BD1 CN1 Q2 U1 4 R9 FB VDD VIN SENSE RI RT 1 R12 7 R16 6 5 R11 R10 SG5842A/JA C9 C11 + R8 4 1 THER2 1 3 8 3 2 GND GATE 2 1 1 2 D4 U2 K 2 3 R13 C10 R14 R U3 VO+ A R15 BOM Reference Component Reference Component BD1 BD 4A/600V Q2 MOS 7A/600V C1 XC 0.68µF/300V R1,R2,R5,R7 R 470Kohm 1/4W C2 XC 0.1µF/300V R3 R 100Kohm 1/2W C3 CC 0.01µF/500V R4 R 47ohm 1/4W C4 EC 120µ/400V R6 R 2Kohm 1/8W C5 YC 222p/250V R8 R 0.3ohm 2W C6 CC 1000pF/100V R9 R 33Kohm 1/8W C7 EC 1000µF/25V R10 R 4.7Kohm 1/8W C8 EC 470µF/25V R11 R 470ohm 1/8W C9 EC 10µF/50V R12 R 0 ohm 1/8W C10 CC 222pF/50V R13 R 4.7Kohm 1/8W C11 CC 470pF/50V R14 R 154Kohm 1/8W 1% D1 LED R15 R 39Kohm 1/8W 1% D2 Diode BYV95C R16 R 100ohm 1/8W D3 TVS P6KE16A THER2 Thermistor TTC104 D4 Diode FR103 T1 Transformer (600µH-PQ2620) F1 FUSE 4A/250V U1 IC SG5842A/JA L1 Choke (900µH) U2 IC PC817 L2 Choke (10mH) U3 IC TL431 L3 Inductor (2µH) VZ1 VZ 9G Q1 Diode 20A/100V © System General Corp. Version 1.4.2 (IAO33.0026.B6) - 11 - www.sg.com.tw • www.fairchildsemi.com October 30, 2007 Product Specification SG5842A/JA Highly Integrated Green-Mode PWM Controller PACKAGE INFORMATION 8PINS-DIP(D) D Θ¢X 5 E1 8 e B E A A1 A2 4 1 L b1 b e Dimensions Symbol Millimeters Min. Typ. A Max. Inches Min. Typ. 5.334 A1 0.381 A2 3.175 0.210 0.015 3.302 3.429 0.125 0.130 b 1.524 0.060 b1 0.457 0.018 D 9.017 9.271 6.223 6.350 E E1 10.160 0.355 0.365 6.477 0.245 0.250 7.620 e Max. 0.135 0.400 0.300 2.540 0.255 0.100 L 2.921 3.302 3.810 0.115 0.130 0.150 eB 8.509 9.017 9.525 0.335 0.355 0.375 θ˚ 0˚ 7˚ 15˚ 0˚ 7˚ 15˚ © System General Corp. Version 1.4.2 (IAO33.0026.B6) - 12 - www.sg.com.tw • www.fairchildsemi.com October 30, 2007 Product Specification SG5842A/JA Highly Integrated Green-Mode PWM Controller 8PINS-SOP(S) 8 C 5 H E F 1 4 b e D Θ A1 L A Dimensions Symbol Millimeter Min. Typ. Max. Inch Min. A A1 b c D E e F H L θ˚ 1.346 0.101 1.752 0.254 0.053 0.004 0.406 0.203 4.648 3.810 1.016 5.791 0.406 0° © System General Corp. Version 1.4.2 (IAO33.0026.B6) 1.270 0.381X45° Typ. Max. 0.069 0.010 0.016 0.008 4.978 3.987 1.524 0.183 0.150 0.040 6.197 1.270 8° 0.228 0.016 0° - 13 - 0.050 0.015X45° 0.196 0.157 0.060 0.244 0.050 8° www.sg.com.tw • www.fairchildsemi.com October 30, 2007 Product Specification SG5842A/JA Highly Integrated Green-Mode PWM Controller © System General Corp. Version 1.4.2 (IAO33.0026.B6) - 14 - www.sg.com.tw • www.fairchildsemi.com October 30, 2007