YD3842 YOUDA INTEGRATED CIRCUIT CURRENT MODE PWM CONTROL CIRCUITS—YD3842 DESCRIPTION The YD3842 provides the necessary features to implement off-line or DC fixed frequency current mode control schemes with a minimal external parts count. FEATURES *Optimized For Off-line and DC to DC Converts *Low Start up Current *Automatic Feed Forward Compensation *Pulse-by-Pulse Current Limiting *Under-voltage Lookout with Hysteresis *Double Pulse Suppression *High Current Totem Pole Output *Internally Trimmed Band-gap Reference *500kHz Operation BLOCK DIAGRAM 8 7 6 5 UVL 1/2 5V REF S/R VCC R S + EA - 1/3 OSC 1V 1 2 3 4 WuXi YouDa Electronics Co., Ltd Add: No.5 Xijin Road, National Hi-Tech Industrial Development Zone, Wuxi Jiangsu China Tel: 86-510-85205117 86-510-85205106 Fax: 86-510-85205110 Website: www.e-youda.com SHENZHEN OFFICE Tel： 86-755-83740369 Fax： 86-755-83741418 Ver 5.0 1 of 4 2006-7-10 YD3842 YOUDA INTEGRATED CIRCUIT ABSOLUTE MAXIMUM RATINGS(Tamb=25℃) PARAMETER SYMBOL VALUE UNIT Supply Voltage (Low impedance Source) VCC 30 V Output Current Io ±1 A Analog Inputs(pin 2, 3) VI(ANA) -0.3 to +6.3 V lSINK(EA) 10 mA PD 1.0 W Error Amplifier Output Sink Current Power Dissipation ELECTRICAL CHARACTERISTICS (Tamb=25℃, VCC1=10V, Vcc2=9.5V, unless otherwise specified) PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT VREF Tj=25℃, Io=1mA 4.90 5.00 5.10 V Reference Section Output Voltage Line Regulation △ VREF 12≤VIN≤25V 6 20 mV Load Regulation △ VREF 1≤lo=20mA 6 25 MV 10Hz≤f≤10kHz, Tj=25℃(note 2) 50 6 mV Ta=25℃, 1000Hrs (note 2) 5 25 mV -30 -100 -180 mA 47 52 57 kHz 12≤Vcc≤25V 0.2 1 % Tmin≤TA≤Tmax (note 2) 5 % Vosc Vpin 4 peak to peak 1.7 V Input Voltage VI(EA) Vpin 1=2.5V Input Bias Current lBIAS Output Noise Voltage Vose Long Term Stability Output Short Circuit lsc Oscillator Section Initial Accuracy f Voltage Stability △ △ f/ Vcc Temp Stability Amplitude Tj=25℃ Error Amplifier Section 2.42 2.50 2.58 V -0.3 -2 μA AVOL 2≤Vo≤4V 60 90 dB Unity Gain Bandwidth Tj=25℃(note 2) 0.7 1 PSRR 12≤Vcc≤25V 60 70 dB 6.0 mHz Output Sink Current lsink Vpin2=2.7V, Vpin 1=1.1V 2 6 mA Output Source Current lsource Vpin 2=2.3V, Vpin 1=5V -0.5 -0.8 mA Vout High VOH Vpin 2=2.3V, RL=15kΩ to GND 5 6 V Vout Low VOL Vpin 2=2.7V, Vpin 1=1.1V WuXi YouDa Electronics Co., Ltd 2 of 4 0.7 1.1 V Website: www.e-youda.com YD3842 YOUDA INTEGRATED CIRCUIT Current Sense Section Gain Gv (note 3, 4) 2.85 3 3.15 V/V Maximum Input Signal VI(MAX) Vpin 1=5V(note 3) 0.9 1 1.1 V PSRR 12≤Vcc≤25V Input Bias Current 70 -2 -10 μA Vpin 3=0 to 2V 150 300 ns lsink=20mA 0.1 0.4 V lsink=200mA 1.5 2.2 V lBIAS Delay to Output dB Output Section Output Low Level VOL Output High Level VOH Rise Time tR Fall Time tF lsource=20mA 13 13.5 V lsource=200mA 12 13.5 V Tj=25℃, CL=1nF (note 2) Tj=25℃, CL=1nF(note 2) UVLO Saturation Vcc=5V, lsink=10mA 50 150 ns 50 150 ns 0.7 1.2 V Under-Voltage lockout Output Section Start Threshold VTH(ST) 14.5 16 17.5 V Min. Operating Voltage After Turn On VOPR(min) 8.5 10 11.5 V Maximum Duty Cycle D(MAX) 95 07 100 % Minimum Duty Cycle D(MIN) 0 % 0.5 1 mA 17 mA PWM Section Total Standby Current Start-up Current lST Operating Supply Current Icc(OPR) Vpin 2=Vpin 3=0V 11 Vcc Zener Voltage Vz Icc=25mA 34 V APPLICATION CIRCUIT 4.7ＫΩ Vref 5κΩ 8 2 7 3 6 4 5 A 0.1μＦ Isense Adjust 4.7ＫΩ Error Amp Adjust 1 0.1μＦ 100ＫΩ RT VCC 1κΩ /1Ｗ OUTPUT CT WuXi YouDa Electronics Co., Ltd 3 of 4 Website: www.e-youda.com YD3842 YOUDA INTEGRATED CIRCUIT OUTLINE DRAWING WuXi YouDa Electronics Co., Ltd 4 of 4 Website: www.e-youda.com