CYStech Electronics Corp. Spec. No. : C151N6 Issued Date : 2012.11.08 Revised Date : Page No. : 1/11 Current Mode PWM Controller MC7773N6 Description MC7773N6 is a highly integrated current mode PWM control IC optimized for high performance low standby power offline flyback converter applications. To meet the international power conservation requirements, optimized green mode is integrated to improve the efficiency at light or no load conditions with no audible noise. Slope compensation is integrated to ensure the stability at high load. Lead edge blanking is integrated to prevent the false trigger at the transition of the switch. Soft switching control at the gate drive can improve the EMI performance of the power supply. The Gate-drive output is clamped at 12V to protect the power MOS. Features ●Frequency jitter function to improve EMI performance of power supply ●No-audible-noise green mode control ●Multi operation mode: Fixed-frequency CCM, green mode and burst mode. ●No load input power under 100mW ●Internal slope compensation ●Low VDD startup current and low operating current ●Leading edge blanking ●UVLO 8.5V / 15.5V ●Gate max output voltage clamp at 12V ●Overload Protection (OLP) with auto-recovery ●Line compensation over current protection (OCP) with auto-recovery ●Over Temperature Protection (OTP) witch latch ●VDD Over Voltage Protection (OVP) witch latch Applications Offline AC/DC flyback converter for ● Battery Charger ● Power Adaptor ● Set-Top Box Power Supplies ● Open-frame SMPS ● PC 5V Standby Power Ordering Information Device Package Shipping MC7773N6 SOT-23-6L (Pb-free lead plating) 3000 pcs / tape & reel MC7773N6 CYStek Product Specification CYStech Electronics Corp. Spec. No. : C151N6 Issued Date : 2012.11.08 Revised Date : Page No. : 2/11 Typical Application Circuit Pin Configuration Pin Assignment Pin Name GND FB PT SENSE VDD GATE MC7773N6 Pin Number Pin Function 1 Ground Feedback input pin. The PWM duty cycle is determined by voltage level into this pin 2 and the current-sense signal at Pin 6. Connected through a NTC resistor to ground for over temperature shutdown/latch 3 control or connected through Zener to VDD for adjustable over voltage protection. 4 Current sense input pin. Connected to MOSFET current sensing resistor node. 5 Chip DC power supply pin. 6 Totem-pole gate drive output for the power MOSFET. CYStek Product Specification CYStech Electronics Corp. Spec. No. : C151N6 Issued Date : 2012.11.08 Revised Date : Page No. : 3/11 Function Block Diagram Absolute Maximum Ratings Parameter VDD to GND VDD clamped current VDD clamped voltage VFB, VSENSE and VRI to GND Maximum Junction Temperature (Tj MAX) Storage Temperature Range Value +29 10 32 -0.3~+7 -20 ~ +150 -55 ~ +160 Unit V mA V V °C °C Note：Stresses beyond those listed under “Absolute Maximum Ratings" may cause permanent damage to the device. Recommended Operating Conditions ● Supply Voltage, VDD………………………………………………………………………+10V to +30V ● Operating Temperature Range………………………………………………………….-20°C to +85°C ● Power Dissipation (RθJA=250°C/W) @25°C, FR-4 PCB , 2oz…………………………………….0.4W ESD Information ● Human Body Mode………………………………………………………………………………2000V ● Machine Mode…………………………………………………………………………………….200V MC7773N6 CYStek Product Specification Spec. No. : C151N6 Issued Date : 2012.11.08 Revised Date : Page No. : 4/11 CYStech Electronics Corp. Electrical Characteristics (TA = 25°C, VDD=16V if not otherwise noted) Parameter Symbol Test Conditions Min Typ Max Units 3 20 uA SUPPLY SECTION Vdd=12V, measure current into VDD pin VDD=16V,VFB=3V Chip start up current via VDD pin I_set Operation current I_op VDD UVLO enter UVLO_L 7.5 8.5 9.5 V VDD UVLO exit UVLO_H 14.5 15.5 16.5 V VDD OVP VDD_OVP 30 32 34 V VZ(VDD clamp voltage) VDD_CLP Iz(Idd)=10mA 30 32 34 V PWM input gain A_PWM ΔVFB/ΔVCS VFB open loop voltage VFB_O 1.4 mA FEEDBACK SECTION Short FB pin to gnd and measure current 2 V/V 4.2 V 0.35 mA FB pin short circuit current VFB_S Burst mode on threshold V_BM_on 0.675 V Burst mode off threshold V_BM_off 0.575 V Power limiting FB threshold VFB_th_P 3.7 V Power limiting delay time T_PL_D 88 ms Input impedance R_FB 16 KΩ OSCILLATOR Soft start time T_ss 4 ms Burst mode switching frequency F_burst 22 kHz Normal operation frequency F_nor Frequency modulation range F_d_jit ±4 Jitter frequency F_jitter 32 Hz Frequency temperature stability F_d_tem 4 kHz Leading edge blanking time T_blank 220 nS Sense pin input impedance R_sense 40 kΩ Over current threshold voltage at zero duty cycle VTH_OC_0 FB=3.3V Over current threshold voltage at max. switching on time VTH_OC_1 FB=3.3V 0.9 V Over current protect delay T_OC_D CS>VTH_OC, FB=3.3V, CL=1nF @Gate 120 nS Output low level VOL Io=20mA Output high level VOH Io=20mA 60 65 70 kHz % CURRENT SENSE SECTION 0.72 0.75 0.78 V GATE OUTPUT 1 6 V V Output voltage clamped level VO_clamp 12 V Output rising time Tr Cl=1nf 175 nS Output falling time Tf Cl=1nf 85 ns PT Pin PT pin source current I_PT Thresh hold of OTP V_OTP MC7773N6 95 100 105 μA 0.95 1 1.05 V CYStek Product Specification Spec. No. : C151N6 Issued Date : 2012.11.08 Revised Date : Page No. : 5/11 CYStech Electronics Corp. OTP debounce time T_OTP 6 cycle External OVP trigger point Vth_OVP 4 V Float voltage at PT pin V_PT_FL 2.3 V Typical Characteristics (TA = 25°C, VDD=16V if not otherwise noted.) Start Current Vs VDD Voltage Operation Current VS Load UVLO Voltage& Operation Current UVLO (On) Voltage VS Temp UVLO (Off) Voltage VS Temp MC7773N6 CYStek Product Specification CYStech Electronics Corp. Spec. No. : C151N6 Issued Date : 2012.11.08 Revised Date : Page No. : 6/11 OPERATION DESCRIPTION Over-view description The MC7773N6 includes all necessary function to build an easy and cost effective solution for low power supplies to meet the international power conservation requirements. Start-up current Startup current of MC7773N6 is designed to be very low so that VDD could be charged up above UVLO (exit) threshold level and device starts up quickly. Also a large value startup resistor can be used to minimize the power loss. Green Mode Operation （Patent） At light load or no load condition, the switch loss become the major loss of the power supply, to reduce the power wasted in light and no load condition, based on a special designed voltage controlled oscillator, green mode operation of the power supply can be achieved by using MC7731N6. The controller will judge the load condition based on the voltage of FB pin. In light load the FB voltage will decrease, when VFB is lower than a set threshold voltage, a FB depending time (TR2) will be generated by the oscillator and decrease the operating frequency of the power supply, the minimum frequency is set about 22kHZ. The function block and the working waveform can be depicted as below: When VFB decreases further, the power supply will enter into burst mode operation to decrease the power consumed at no load condition. Besides there is no audible noise in any load condition. MC7773N6 CYStek Product Specification CYStech Electronics Corp. Spec. No. : C151N6 Issued Date : 2012.11.08 Revised Date : Page No. : 7/11 Built-in Slope Compensation and Frequency Shuffling While MC7773N6 works in CCM mode, slope compensation and frequency shuffling is activated. The sensed voltage across the sense resistor is used for pwm control, and pulse by pulse current limit, Built-in slope compensation circuit adds a voltage ramp onto the current sense input voltage. This greatly improves the close loop stability and prevents the sub-harmonic oscillation of peak current mode pwm control scheme. To improve the EMI performance, the frequency of CCM mode is shuffling to 65kHz ± 4%. Line Slope Compensation Adjusting the RSENSE can set the Max output power of the power supple mode. The current flowing by the power MOSFET has an extra value due to the system delay T that the current detected from the sense pin to power MOSFET cut off in the MC7773N6. To guarantee the output power is a constant for universal input AC voltage, there is a positive ramp signal to compensate the system delay T and the line input. At lower line-input voltage the higher OCP threshold will bring constant power OCP as below. Leading Edge Blanking Each time when the power MOSFET is switched on, a turn-on spike will inevitably occur on the sense-resistor. To avoid premature termination of the switching pulse, a 300 nsec 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. Gate Driver The output stage of MC7773N6 is a fast totem pole gate driver. Cross conduction has been avoided to minimize heat dissipation, increases efficiency and enhances reliability. The output driver is clamped by an internal 18V Zener diode in order to protect power MOSFET transistors against undesirable gate over voltage. A soft driving waveform is implemented to minimize EMI. MC7773N6 CYStek Product Specification CYStech Electronics Corp. Spec. No. : C151N6 Issued Date : 2012.11.08 Revised Date : Page No. : 8/11 Protect Functions To increase the reliability of power supply system many protection functions is integrated in this controller, including Cycle-by-Cycle current limiting (OCP), Over Load Protection (OLP), Over Temperature Protection(OTP), External Over Voltage Protection (OVP) and over voltage clamp, Under Voltage Lockout on VDD (UVLO). At overload condition when FB input voltage exceeds power limit threshold value for more than TD_PL (power limit debounce time), the controller reacts to shut down the output power MOSFET. Device restarts when VDD voltage drops below UVLO limit. VDD is supplied by transformer auxiliary winding output. It is clamped when VDD is higher than threshold value. The power MOSFET is shut down when VDD drops below UVLO limit and device enters power on start-up sequence thereafter. Pin floating protection for CS, FB, PT is also added. While one of this happens, the GATE is turned off. PT Pin Typical Application Circuit MC7773N6 CYStek Product Specification CYStech Electronics Corp. Spec. No. : C151N6 Issued Date : 2012.11.08 Revised Date : Page No. : 9/11 Reel Dimension Carrier Tape Dimension MC7773N6 CYStek Product Specification CYStech Electronics Corp. Spec. No. : C151N6 Issued Date : 2012.11.08 Revised Date : Page No. : 10/11 Recommended wave soldering condition Product Pb-free devices Peak Temperature 260 +0/-5 °C Soldering Time 5 +1/-1 seconds Recommended temperature profile for IR reflow Profile feature Average ramp-up rate (Tsmax to Tp) Preheat −Temperature Min(TS min) −Temperature Max(TS max) −Time(ts min to ts max) Time maintained above: −Temperature (TL) − Time (tL) Peak Temperature(TP) Time within 5°C of actual peak temperature(tp) Ramp down rate Time 25 °C to peak temperature Sn-Pb eutectic Assembly Pb-free Assembly 3°C/second max. 3°C/second max. 100°C 150°C 60-120 seconds 150°C 200°C 60-180 seconds 183°C 60-150 seconds 240 +0/-5 °C 217°C 60-150 seconds 260 +0/-5 °C 10-30 seconds 20-40 seconds 6°C/second max. 6 minutes max. 6°C/second max. 8 minutes max. Note : All temperatures refer to topside of the package, measured on the package body surface. MC7773N6 CYStek Product Specification Spec. No. : C151N6 Issued Date : 2012.11.08 Revised Date : Page No. : 11/11 CYStech Electronics Corp. SOT-23-6L Dimension A D Marking: d1 d2 6 5 4 Style: Pin 1. GND Pin 2. FB Pin 3. PT Pin 4. SENSE Pin 5. VDD Pin 6. GATE B C ○ 1 2 3 73ABC Device Name Date Code E 6-Lead SOT-23-6L Plastic Surface Mounted Package CYStek Package Code: N6 I F L H J G Inches Min. Max. 0.1063 0.1220 0.1024 0.1181 0.0551 0.0709 0.0748 REF 0.0374 REF 0.0374 REF 0.0118 0.0217 DIM A B C D d1 d2 E Millimeters Min. Max. 2.70 3.10 2.60 3.00 1.40 1.80 1.90 REF 0.95 REF 0.95 REF 0.30 0.55 K DIM F G H I J K L Inches Min. Max. 0.0472 REF 0 0.0059 0.0086 0.0047 REF 0.0146 REF 0.0236 REF 0° 10° Millimeters Min. Max. 1.20 REF 0 0.15 0.22 0.12 REF 0.37 REF 0.60 REF 0° 10° Notes : 1.Controlling dimension : millimeters. 2.Maximum lead thickness includes lead finish thickness, and minimum lead thickness is the minimum thickness of base material. 3.If there is any question with packing specification or packing method, please contact your local CYStek sales office. Material : • Mold Compound : Epoxy resin family, flammability solid burning class:UL94V-0. Important Notice: • All rights are reserved. Reproduction in whole or in part is prohibited without the prior written approval of CYStek. • CYStek reserves the right to make changes to its products without notice. • CYStek semiconductor products are not warranted to be suitable for use in Life-Support Applications, or systems. • CYStek assumes no liability for any consequence of customer product design, infringement of patents, or application assistance. MC7773N6 CYStek Product Specification