FEATURES Green-Mode PWM Supports the Blue Angel Standard Low Start-up Current (9uA) Low Operating Current (3mA) Leading-Edge Blanking Constant Output Power Limit Universal Input Built-in Synchronized Slope Compensation Current Mode Operation Cycle-by-cycle Current Limiting Under Voltage Lockout (UVLO) Programmable PWM Frequency with Frequency Hopping V DD Over Voltage Protection (Auto Restart) Gate Output Voltage Clamped at 7V Low Cost Few External Components Required Small SOT-26 and Dip 8 Packages APPLICATIONS General-purpose switching mode power supplies and 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, and consumer electronics Replacements for linear transformers and RCC SMPS PC 5V standby power. DESCRIPTION This highly integrated PWM controller provides several special enhancements designed to meet the low standby-power needs of low-power SMPS. To minimize standby power consumption, the proprietary green-mode function provides off-time modulation to linearly decrease the switching frequency under light-load conditions. This green-mode function enables the power supply to easily meet even the strictest power conservation requirements. The BiCMOS fabrication process enables reducing the start-up current to 9uA, and the operating current to 3mA. To further improve power conservation, a large start-up resistance can be used. Built-in synchronized slope compensation ensures the stability of peak current mode control. Proprietary internal compensation provides a constant output power limit over a universal AC input range (90V AC to 264V AC ). Pulse-by-pulse current limiting ensures safe operation even during short-circuits. To protect the external power MOSFET from being damaged by supply over voltage, the s output driver is clamped at 7V. controllers can be used to improve the performance and reduce the production cost of power supplies. The is the best choice for replacing linear and RCC-mode power adapters. It is available in 8-pin DIP and 6-pin SOT-26 packages. TYPICAL APPLICATION System General Corp. - - www.sg.com.tw www.fairchildsemi.com Version.2.(IAO33.0067.B2) September 28,2007
MARKING DIAGRAMS PIN CONFIGURATION AAJMW AAJ: M: Mask Version W: Week code A~Z=W~W26 A~Z=W27~W52 : Lead Free Package GND FB RI SOT-26 GATE VDD SENSE DIP-8 TP XXXXXXXXYWWV T: D=DIP P: Z =Lead Free Null=Regular Package XXXXXXXX: Wafer Lot Y: Year; WW: Week V: Assembly Location GATE VDD NC SENSE GND FB NC RI ORDERING INFORMATION Part Number Pb-Free Package TZ DZ 6-Pin SOT-26 8-Pin DIP-8 PIN DESCRIPTIONS Pin No. Name Type Function DIP-8(SOT-26) GATE / (6) Driver Output The totem-pole output driver for driving the power MOSFET. VDD 2 / (5) Supply Power supply. NC 3 NC pin. SENSE 4 / (4) Analog Input Current sense. This pin senses the voltage across a resistor. When the voltage reaches the internal threshold, PWM output is disabled. This activates over-current protection. This pin also provides current amplitude information for current-mode control. A resistor connected from the RI pin to ground will generate a constant current RI 5 / (3) source for the. This current is used to charge an internal capacitor, to Analog determine the switching frequency. Increasing the resistance will reduce the Input/Output amplitude of the current source and reduce the switching frequency. A 95kΩ resistor R i results in a 50uA constant current I i and a 70kHz switching frequency. NC 6 NC pin. Feedback. The FB pin provides the output voltage regulation signal. It provides FB 7 / (2) Analog Input feedback to the internal PWM comparator, so that the PWM comparator can control the duty cycle. GND 8 / () Supply Ground. System General Corp. - 2 - www.sg.com.tw www.fairchildsemi.com
BLOCK DIAGRAM System General Corp. - 3 - www.sg.com.tw www.fairchildsemi.com
ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit V VDD DC Supply Voltage * 30 V V FB Input Voltage to FB Pin -0.3 to 7 V V SENCE Input Voltage to Sense Pin -0.3 to 7 V T J Operating Junction Temperature 50 C RθJA Thermal Resistance (Junction to Air) SOT 208.4 C/W DIP 82.5 C/W T STG Storage Temperature Range -55 to +50 C T L Lead Temperature (Wave soldering or IR, 0 seconds) 260 C V ESD-HBM ESD Capability, HBM Model 3.5 kv V ESD-MM ESD Capability, Machine Model 200 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 V DD DC Supply Voltage 22 V T A Operating Ambient Temperature -20 to +85 C * For proper operation. ELECTRICAL CHARACTERISTICS (V DD = 5V; T A = 25 C) VDD Section Symbol Parameter Test Condition Min. Typ. Max. Unit V DD-OP Continuously Operation Voltage 22 V V DD-ON Turn-On Threshold Voltage 5.5 6.5 7.5 V V DD-OFF Turn-Off Threshold Voltage 0.5.5 2.5 V I DD-ST Startup Current V DD=V DD-ON 0.V 9 5 µa I DD-OP Operating Supply Current V DD=5V, GATE with nf to GND 3 3.5 ma V DD-OVP VDD Over-voltage-protection level (Auto Restart) 24 25 26 V t D-VDDOVP VDD Over-voltage-protection Debounce (Auto Restart) 25 µs V DD-G OFF V DD Low-threshold Voltage to Exit Green-off Mode V DD-OFF + V System General Corp. - 4 - www.sg.com.tw www.fairchildsemi.com
Feedback Input Section Symbol Parameter Test Condition Min. Typ. Max. Unit Z FB Input Impedance 5 KΩ V FB-OPEN FB Output High Voltage 5 V V FB-OL FB Open-loop Trigger Level 4.3 4.6 4.9 V t D-OLP The delay time of FB pin Open Loop Protection 56 ms V FB-N Green-Mode Entry FB Voltage 2.6 2.85 3. V V FB-G Green-Mode Ending FB Voltage 2.20 V S G Green-Mode Modulation Slope R I=95KΩ 40 75 00 Hz/mV Current Sense Section Symbol Parameter Test Condition Min. Typ. Max. Unit Z SENSE Input Impedance 0 KΩ t PD Delay to Output 40 55 00 ns V STHFL Flat Threshold Voltage for Current Limit 0.9 0.96.0 V V STHVA Valley Threshold Voltage for Current Limit 0.75 0.80 0.85 V t LEB Leading-Edge Blanking Time 250 300 350 ns DCY SAW Duty Cycle of SAW Limit 40 % Oscillator Section Symbol Parameter Test Condition Min. Typ. Max. Unit F OSC Normal PWM Frequency Center Frequency 65 70 75 R I=95KΩ Hopping Range ±4.9 T HOP Hopping Period R I=95KΩ 3.7 ms F OSC-G Green-Mode Frequency R I=95KΩ 22 KHz F DV Frequency Variation versus V DD Deviation V DD=3.5 to 22V 0 0.02 2 % F DT Frequency Variation versus Temp. Deviation T A=-20 to 85 C 2 % KHz Output Section Symbol Parameter Test Condition Min. Typ. Max. Unit DCY MAX Maximum Duty Cycle 70 75 80 % V GATE-L Output Voltage Low V DD=5V, I o=20ma.5 V V GATE-H Output Voltage High V DD=3.5V, I o=20ma 8 V tr Rising Time V DD=5V, C L=nF 50 ns tf Falling Time V DD=5V, C L=nF 55 ns V GATE-CLAMP Output Clamp Voltage V DD=22V 6 7 8 V System General Corp. - 5 - www.sg.com.tw www.fairchildsemi.com
TYPICAL CHARACTERISTICS Turn-On Threshold Voltage (V DD-ON ) vs Temperature Turn-Off Threshold Voltage (V DD-OFF ) vs Temperature 7.0 4 6.8 3 VDD-ON (V) 6.6 6.4 6.2 VDD-OFF (V) 2 0 9 6.0-40 -25-0 5 20 35 50 65 80 95 0 25 8-40 -25-0 5 20 35 50 65 80 95 0 25 Startup Current (I DD-ST ) vs Temperature Operating Supply Current (I DD-OP ) vs Temperature.4 3.0.2 2.8 IDD-ST (ua).0 0.8 0.6 0.4 IDD-OP (ma) 2.6 2.4 2.2 0.2-40 -25-0 5 20 35 50 65 80 95 0 25 2.0-40 -25-0 5 20 35 50 65 80 95 0 25 Normal PWM Frequency (F OSC ) vs Temperature Maximum Duty Cycle (DCY MAX ) vs Temperature 72.0 75.0 7.5 74.8 FOSC (Khz) 7.0 DCY MAX (%) 74.6 74.4 70.5 74.2 70.0-40 -25-0 5 20 35 50 65 80 95 0 25 74.0-40 -25-0 5 20 35 50 65 80 95 0 25 System General Corp. - 6 - www.sg.com.tw www.fairchildsemi.com
Green-Mode Entry FB Voltage (V FB-N ) vs Temperature Green-Mode Ending FB Voltage (V FB-G ) vs Temperature 3.2 2.30 3.0 2.28 VFB-N (V) 2.8 2.6 VFB-G (V) 2.26 2.24 2.4 2.22 2.2-40 -25-0 5 20 35 50 65 80 95 0 25 2.20-40 -25-0 5 20 35 50 65 80 95 0 25 340 Leading-Edge Blanking Time (t LEB ) vs Temperature 3.5 Operating Supply Current vs VDD voltage 330 3.0 tleb (ns) 320 30 300 290 IDD-OP (ma) 2.5 2.0.5 280-40 -25-0 5 20 35 50 65 80 95 0 25.0 2 3 4 5 6 7 8 9 20 2 22 23 24 VDD (V) System General Corp. - 7 - www.sg.com.tw www.fairchildsemi.com
OPERATION DESCRIPTION devices integrate many useful designs into one controller for low-power switch-mode power supplies. The following descriptions highlight some of the features of the series. Start-up Current The start-up current is only 9uA. Low start-up current allows a start-up resistor with a high resistance and a low-wattage to supply the start-up power for the controller. A.5 MΩ, 0.25W, start-up resistor and a 0uF/25V V DD hold-up capacitor would be sufficient for an AC-to-DC power adapter with a wide input range (00V AC to 240V AC ). Operating Current The operating current has been reduced to 3mA. The low operating current results in higher efficiency and reduces the V DD hold-up capacitance requirement. Green-Mode Operation The proprietary green-mode function provides off-time modulation to linearly decrease the switching frequency under light-load conditions. On-time is limited to provide stronger protection against brownouts and other abnormal conditions. The feedback current, which is sampled from the voltage feedback loop, is taken as the reference. Once the feedback current exceeds the threshold current, the switching frequency starts to decrease. This green-mode function dramatically reduces power consumption under light-load and zero-load conditions. Power supplies using the can easily meet even the strictest regulations regarding standby power consumption. Oscillator Operation A resistor connected from the RI pin to ground will generate a constant current source for the. This current is used to charge an internal capacitor. The charge-time determines the internal clock speed and the switching frequency. Increasing the resistance will reduce the amplitude of the input current and reduce the switching frequency. A 95kΩ resistor R i results in a 50uA constant current I i and a 70kHz switching frequency. The relationship between R i and the switching frequency is: 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 320nsec leading edge blanking time is built in. Conventional RC filtering can therefore be omitted. During this blanking period, the current-limit comparator is disabled and it cannot switch off the gate driver. Constant Output Power Limit When the SENSE voltage across the sense resistor R s reaches the threshold voltage (around 0.96V), the output GATE drive will be turned off following a short propagation delay t PD. This propagation delay will introduce an additional current proportional to t PD *V in /L p. The propagation delay is nearly constant regardless of the input line voltage V IN. Higher input line voltages will result in larger additional currents. At high input line voltages, the output power limit will be higher than at low input line voltages. To compensate for this output power limit variation across a wide AC input range, the threshold voltage is adjusted by adding a positive ramp. This ramp signal rises from 0.80V to 0.96V, and then flattens out at 0.96V. A smaller threshold voltage forces the output GATE drive to terminate earlier. This reduces the total PWM turn-on time and makes the output power equal to that of low line input. This proprietary internal compensation ensures a constant output power limit for a wide AC input voltage range (90VAC to 264VAC). Under Voltage Lockout (UVLO) The turn-on and turn-off thresholds of the are fixed internally at 6.5V/.5V. During start-up, the hold-up capacitor must be charged to 6.5V through the start-up resistor, so that the will be enabled. The hold-up capacitor will continue to supply V DD until power can be delivered from the auxiliary winding of the main transformer. V DD must not drop below.5v during this start-up process. This UVLO hysteresis window ensures that hold-up capacitor will be adequate to supply V DD during start-up. fpwm 6650 = RI (kω) (khz ) Leading-Edge Blanking System General Corp. - 8 - www.sg.com.tw www.fairchildsemi.com
Gate Output 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 7V Zener diode in order to protect power MOSFET transistors against undesired over-voltage gate signals. Built-in Slope Compensation The sensed voltage across the current sense resistor is used for current mode control and pulse-by-pulse current limiting. Built-in slope compensation will improve stability and prevent sub-harmonic oscillations due to peak-current mode control. The has a synchronized, positively-sloped ramp built-in at each switching cycle. The slope of the ramp is: 0.36 Duty Duty(max.) Noise Immunity Noise from the current sense or the control signal can cause significant pulse width jitter, particularly in continuous-conduction mode. While slope compensation helps alleviate these problems, further precautions should still be taken. Good placement and layout practices should be followed. Avoiding long PCB traces and component leads, locating compensation and filter components near the, and increasing the power MOS gate resistance is advised. System General Corp. - 9 - www.sg.com.tw www.fairchildsemi.com
REFERENCE CIRCUIT L F CX 2 BD 4 L 2 C C2 R C3 R3 N C6 3 2 3 R9 U GND GATE FB VDD RI SENSE 6 5 4 R7 C R2 R5 2 2 3 R5 D Q R6 R4 0 T,2 9 8 5 7 3,4 D4 2 R0 C7 C8 L2 2 2 D5 C9 VO GND R8 D2 2 C4 R U2 3 4 2 R4 R3 CY C0 2 3 U3 R2 BOM Reference Component Reference Component BD BD A/500V L2 0uH 6mm CX (Optional) XC 0.uF Q MOSFET A/600V CY (Optional) YC 02P/400V (Y) R,R2 R 750KΩ 206 C CC 03P/500V R3,R4 R 47KΩ 206 C2 EC 0µF/400V 05 C R5 R 47Ω 206 C3 CC 02P/500V R6 R 4.7Ω 206 C4 EC 0µ/50V R7 R 00Ω 0805 C6 CC 472P 0805 R8 R 0Ω 206 C7 (Optional) CC 02P/00V 206 R9 R 00KΩ 0805 C8 EC 470µ/0V 05 C R0 (Optional) R 0Ω 206 C9 EC 220µ/0V 05 C R R 00Ω /8W C0 CC 222P 0805 R2 R 33KΩ 0805 C N.C. R3 R 33KΩ /8W D Diode FRI07 R4 R 4.7KΩ 0805 D2 Diode FR02 R5 R 0Ω 0805 D4 Diode SB360 T EE-6 D5 (Optional) ZD 6.8V 0.5W U IC F R Ω/0.5W U2 PC87 L 20mH 6*8mm U3 TL43 System General Corp. - 0 - www.sg.com.tw www.fairchildsemi.com
PACKAGE INFORMATION 8 PINS - DIP (D) D 8 5 Θ X E E eb 4 A A2 A L b b e Dimensions Symbol Millimeters Inches Min. Typ. Max. Min. Typ. Max. A 5.334 0.20 A 0.38 0.05 A2 3.75 3.302 3.429 0.25 0.30 0.35 b.524 0.060 b 0.457 0.08 D 9.07 9.27 0.60 0.355 0.365 0.400 E 7.620 0.300 E 6.223 6.350 6.477 0.245 0.250 0.255 e 2.540 0.00 L 2.92 3.302 3.80 0.5 0.30 0.50 e B 8.509 9.07 9.525 0.335 0.355 0.375 θ 0 7 5 0 7 5 System General Corp. - - www.sg.com.tw www.fairchildsemi.com
6 PINS - SOT (T) b D 6 4 Detail A E E e 3 e R c θ R L2 A A A2 θ L L θ Dimensions Detail A Symbol Millimeters Inches Min. Typ. Max. Min. Typ. Max. A.45 0.057 A 0.5 0.006 A2 0.90.5.30 0.036 0.045 0.05 b 0.30 0.50 0.0 0.020 c 0.08 0.22 0.003 0.009 D 2.90 0.4 E 2.80 0.0 E.60 0.063 e 0.95 0.037 e.90 0.075 L 0.30 0.45 0.60 0.020 0.08 0.024 L 0.60 0.024 L2 0.25 0.00 R 0.0 0.004 R 0.0 0.25 0.004 0.00 θ 0 4 8 0 4 8 θ 5 0 5 5 0 5 System General Corp. - 2 - www.sg.com.tw www.fairchildsemi.com
System General Corp. - 3 - www.sg.com.tw www.fairchildsemi.com