LR59 20 High Performance Current Mode PWM Switching Power Supply Controller DESCRIPTION The LR5920 is a current mode PWM switching power supply FEATURES ¦ Built-in 750V high voltage power switching tube with minimal controller that specifically designed for AC/DC converter with high external parts count perfo rmance versus cost ratio. It provides continuo us output power up to 12W in the bro ad voltage range o f 8 5V – 265V.Its o ptimized and highly ¦ ¦ reaso nable circuit design has made it po ssible to minimize the total cost below 0.25W of the pro duct. This power supply co ntroller could be used in typical flyback circuit topology to constitute simp le AC/DC converter. The ¦ ¦ internal initiating circuit of 5920 has been designed with a uniq ue means the o ver-current and overload of the controller of current sink to complete the startup using the amplifying function of the ¦ power switching tube. This will significantly reduce the power resistance of the power tube consumption of the start-up res istor; and when the output power becomes smaller, 5920 will auto matically lower its operating frequency to ¦ ¦ enable very lo w standby power consumption. reduce the power consumption of the start-up resistor more than ten W hen the po wer tube stops, the internal circuit will turn the power tube reverse bias to greatly raise the voltage resistant capacity of OC pin. This will ensure the safety o f the po wer tube. The internal design of the and output short-circuit, so as to increase the reliab ility of the power supply. A vo ltage reference of 2.5V is also integrated in the 5920 to provide accurate power supply to the clock circuit, and the clock frequency may be set by external timing capacitance. P resently, standard DIP8 package and environmental friendly lead -free package in compliance with Euro pean standard can be supplied. Reduced frequency at low o utput with standby po wer consumption Built-in slope and feedback compensation function Separate upper limit current inspectio n co ntroller to handle timely Turn off periodic bias output of the emitter to improve the vo ltage Built-in thermal protective circuit Complete start - up using amplification of the switching po wer tube to times ¦ ¦ 5920 is also provided with o ver - load and saturation preventive function capable of preventing diso rders such as overload, transformer saturation Latched P WM and pulse - by - pulse current limiting inspection Automatic VCC over - voltage limit Broad voltage output po wer up to 12W and narrow voltage o utput power up to 18W Applications ¦ ¦ P o wer Adapto rs(traveling chargers ,stand - alo ne power set) Internal power supply for Energy - Saving Appliances (such as electro magnetic oven, microwave oven and etc.) LR592 0 High Performance Current Mode PWM Switching Power Supply Controller TYPICAL APPLICATION PACKAGE INFORM ATION PIN FUNCTIONS LR592 0 ABSOLUTE M AXIMUM RATINGS (Note 1) Supply Voltage VCC…………………………….… 18V Pin Input Vo ltage………………………………… VCC+0.3V OC Voltage……………………………..…… -0.3-750V Switching Current………………….………………… 800mA Operating Temperature Range……..………………0-75℃ Total Dissipation Power………………..…… 1000mW Storage Temperature Range…………… -40 - 150℃ Welding Temperature……......……………… +260℃，10S ELECTRICAL CHARACTERISTICS The specifications are applied at T=25℃, VCC=5.5 -7.5V, Ct=680PF, RS=1Ω, unless otherwise noted.(Note 2) Parameter Symbol Conditions Typ Max Units Output Section IOC=10mA M ax. W ithstanding Vo ltage of the Switching Tube Saturatio n Voltage VSA T Output Rise Time TR Output Fall Time TF Output Limiting Current V 1 V CL=1nF 75 ns CL=1nF 75 ns Tj=0-100℃ 270 290 mA Io=1.0mA 2.5 2.6 V Vcc=5.5-9V 2 20 mV Ioc=250mA Reference Section Reference Output Voltage VREF Line Regulation Lo ad Regulation 3 Io= 0.1 -1.2mA Output No ise Voltage F=10Hz-10KHz Long Term Stability 1000 hours@85℃ % mV/℃ 0.2 Temperature Stability 50 5 uV mV Oscillator Section Oscillating Frequency FOSC Ct=680PF 61 67 KHz Voltage Stability Vcc=5.5-9V 1 % Temperature Stability Ta=0-85℃ 1 % Feedback Section Input Impedance V 2.2 Oscillator Amplitude (Vp-p) Pull-up Current FB=2.5V, IS=0V 0.6 0.65 30 P ull- Do wn mA K? Resistor Vcc=5.5-9V 60 70 dB VCS 0.60 0.65 V IL 0.27 0.29 A 60 70 dB 57 61 % 3.5 % Power Supply Suppression Ratio Current Sampling Section Current Sampling Threshold Anti-Upper Limit Current Power Supply Suppression Ratio PWM Section M aximum Duty R atio Minimum Duty Ratio DM A X DM IN Power Supply Current Section Initiating Reception Current 2.4 3.2 mA Initiating Static Current 55 80 uA 3.0 3.3 mA Start - up voltage 8.8 9.0 V Oscillato r Turn - off Vo ltage 4.6 4.8 V Static Current IQ Vcc=8V LR5920 ELECTRICAL CHARACTERISTICS The specifications are applied at T=25℃, VCC=5.5 -7.5V, Ct=680PF, RS=1Ω, unless otherwise noted.(Note 2)(continued) Re-enabling voltage Over - Voltage Limiting Thresho ld Note1: Stresses bey ond thos e listed un de r Abso lute M a ximu m Ra tin gs ma y caus e p e rman en t d a mag e to th e d ev ic e . Exp os u re to any A bso lu M a ximu m Ra tin g con d itio n fo r e xte nd ed p e riods may a ffe ct d ev ic e re liab ility an d life time . 3.6 3.8 4.0 V 9.5 10 10.5 V Note2:T h e 5920 is g ua ran te ed to me et pe rfo rman c e spe c ific a tio ns fro m 0℃ to 70 ℃. Sp ec ific a tions ov e r th e -40℃ to 85℃ ope ra ting te mpe ratu re ran ge a re assu red by d es ig n , c ha ra cte riza tio n a nd co rre lation with statis tica l p roc ess co ntro ls . BLOCK DIAGRAM OPERATION (Refer to Block Diagram) In the start-up stage, when power is on, VR is closed; the pull-up the FB is, the wider the oscillator period will be, until the stop of the current source FB is closed; OE inputs enabling current fro m power tube o scillato r (this feature will lower the stand - by po wer consumption of the to VCC; OB controls the base current of the power tube, limits the switch power source); if the external feedback intends to make VCC collector current of the power tube (i.e. 5920 initiates the reception higher than 10 V, the internal circuit feedback to FB will stabilize VCC at current), so as to ensure the safety of the po wer tube; when VCC voltage 9.8V (with this feature, the internal circuit rather than the external raises up to 8.8 V, the enabling stage ends and it goes into the normal feedback circuit will be used to stabilize the output voltage, but the stage. stabilizing accuracy may be low); in the open period, OB supplies base In the normal stage, VCC voltage should be maintained at 4.8V to current to power tube, OE pulls do wn the emitter of the po wer tube to IS, 9.0V, VR outputs 2 .5 V reference; FB pull - up current so urce is opened; and the OB uses the slope current driving (i.e. the OB o pen current is the the oscillator output OSC1 decides the maximum duty ratio, o utput OSC2 function o f IS, when IS = 0 V, OB open current is appro ximately 40mA, tries to trigger the po wer into open period, and the screened po wer tube then the OB o pen current will increase along with IS linearly, when IS turns o n the current peak; if FB is below 1.8 V (approximately between raises to 0 .6V, the OB open current is appro ximately 100 mA, this feature 1.2V and 1 .8 V), the o scillato r period will then be inc will effectively utilize the output current of OB and lower the power ed, the smaller LR592 0 consumption of 5920), if IS detects the specified current o f FB, it goes protection of 59 20 will widen the oscillato r period when the internal into clo se period; in the close period, OB pulls down, the po wer tube may temperature is above 125℃ to ensure the temperature o f 5920 will not not be turned off immediately, but OE clamps on 2.0V (after the power exceed 135 ℃; the built-in slope compensation will stab ilize the tube turns off, the base will be reverse bias and the voltage withstanding o pen/close period when 5920 capacity is increased); in the open or close perio d, if it detects the current mode. exceeding upper limit of the power tube, then the upper limit flip - flop will is at high duty ratio or in continuo us current W hen VCC lo wers to abo ut 4.6V, the oscillator will be closed, OSC1 be put at the preferential pos ition, forcing FB to decrease and the duty and O SC2 will be at low level, and the power source will be maintained at ratio will turn smaller, so that the power tube and transformer will be close period; when VCC goes on lowering to about 4.2V, 5920 will enter protected; at the beginning of next close period edge or if FB is belo w the enabling stage again. 1.8V, the upper limit flip -flop will reset. Bes ides, the built-in heat Normal Stage Switching Cycle Oscillogram Global Oscillogram LR5920 TEST DATA V IN (V AC ) 90Vac 100Vac 240Vac 265Vac P IN (W) V O UT (V) IO UT (A) V CC (V) 0.1 12.1 0 5.36 3.2 7.6 12.1 12.1 0.2 0.5 6.64 6.64 12.0 15.1 0.1 3.1 7.5 11.9 14.9 0.1 3.0 7.3 11.5 14.4 0.1 3.0 7.4 11.6 14.5 12.1 12.1 12.1 12.1 12.1 12.1 12.1 12.1 12.1 12.1 12.1 12.1 12.1 12.1 12.1 12.1 12.1 0.8 1.0 0 0.2 0.5 0.8 1.0 0 0.2 0.5 0.8 1.0 0 0.2 0.5 0.8 1.0 6.64 6.64 5.28 6.70 6.70 6.70 6.70 4.96 6.96 6.96 6.96 6.96 4.88 7.04 7.04 7.04 7.04 LR5920 (12V) ? VO R P OUT (mVp -p) (W) (%) 0 2.4 6.1 9.7 12.1 0 2.4 6.1 9.7 12.1 0 2.4 6.1 9.7 12.1 0 2.4 6.1 9.7 12.1 75.0 80.3 80.8 80.1 77.4 81.3 81.5 81.2 80.0 83.5 84.3 84.0 80.0 82.4 83.6 83.4 OCP OPP (A) (A) Average ? (%) 1.07 1.36 79.05 1.13 1.45 80.35 1.69 2.13 82.95 1.72 2.17 82.35 CEC Standerd ? (%) Output Voltage and Output Ripple Voltage 85V Vin(V) Iout(A) 0.25 0.50 0.75 1.00 110V 135V Vout(V) Vripple(mV) Vout(V) Vripple(mV) Vout(V) Vripple(mV) 12.18 12.18 12.18 12.18 5.00 9.00 14.00 31.20 12.18 12.18 12.18 12.18 3.52 5.36 8.00 11.60 12.18 12.18 12.18 12.18 3.76 5.84 7.68 8.40 180V Vin(V) Iout(A) Vout(V) 0.25 0.50 0.75 1.00 12.18 12.18 12.18 12.18 220V Vripple(mV) 4.32 6.40 7.00 9.00 Vout(V) 12.18 12.18 12.18 12.18 265V Vripple(mV) 5.12 6.16 7.28 8.48 Vout(V) 12.18 12.18 12.18 12.18 Vripple(mV) 5.36 5.92 6.40 7.76 LR592 0 Test Waveform: Vce waveform: Vin=85V,Vout=12V,Iout=0.5A Vin=85V,Vout=12V,Iout=1A Vin=110V,Vout=12V,Iout=0.5A Vin=110V,Vout=12V,Iout=1A Vin=220V,Vout=12V,Iout=0.5A Vin=220V,Vout=12V,Iout=1A LR59 20 Vin=265V,Vout=12V,Iout=0.5A Vin=265V,Vout=12V,Iout=1A Output Ripple Voltage Vin=85V,Vout=12V,Iout=0.5A Vin=85V,Vout=12V,Iout=1A CH2:Vout CH2:Vout Vin=265V,Vout=12V,Iout=0.5A Vin=265V,Vout=12V,Iout=1A CH2:Vout CH2:Vout LR592 0 Turn On Waveform: Vin=85V,Vout=12V,Iout=1A Vin=110V,Vout=12V,Iout=1A CH2:Vout CH2:Vout Vin=220V,Vout=12V,Iout=1A Vin=265V,Vout=12V,Iout=1A CH2:Vout CH2:Vout Vce and Vout Vin=85V,Vout=12V,Iout=1A Vin=110V,Vout=12V,Iout=1A LR5920 CH2:Vout;CH3:Vce CH2:Vout;CH3:Vce Vin=220V,Vout=12V,Iout=1A Vin=265V,Vout=12V,Iout=1A CH2:Vout;CH3:Vce CH2:Vout;CH3:Vce Short Output: Vin=85V,Vout=12V Vin=110V,Vout=12V CH2:Output Voltage,CH3:Vce CH2:Output Voltage,CH3:Vce Vin=220V,Vout=12V Vin=265V,Vout=12V CH2:Output Voltage,CH3:Vce CH2:Output Voltage,CH3:Vce LR592 0 VOB and VIS Vin=85V,Vout=12V,Iout=1A Vin=110V,Vout=12V,Iout=1A CH2:VOB; CH4:VIS Vin=220V,Vout=12V,Iout=1A CH2:V OB; CH4:V IS Vin=265V,Vout=12V,Iout=1A CH2:V OB; CH4:V IS CH2:V OB; CH4:V IS Temperature: 95 90 85 80 75 70 85V 65 110V 60 220V 265V 55 50 45 40 35 30 0 .00 0.20 0.40 0.60 0.80 1 .00 1.20 LR5920 PACKAGE INFORM ATION DIP-8 Dimensions Symbol Millimeter Min. A A1 A2 b 0.381 3.175 E L eB ?° Min. Inch Typ. 3.302 3.429 9.017 9.271 0.130 8.509 3.302 9.017 3.810 9.525 0.115 0.335 0.365 0.300 0.250 0.100 0.130 0.355 0° 7° 15° 0° 7° 6.350 10.160 0.355 6.477 0.245 2.540 2.921 0.135 0.06 0 0.01 8 7.620 6.223 Max. 0.210 0.015 0.125 1.524 0.457 E E1 Max. 5.334 b1 D Typ. 0.400 15° 0.255 0.150 0.375