ISSUED DATE :2003/05/20 REVISED DATE :2004/09/30B GP3842 HIGH PERFORMANCE CURRENT MODE CONTROLERS Description The GP3842 is high performance fixed frequency current mode controllers. This is specifically designed for Off-Line and DC TO DC converter applications offering the designer a cost-effective solution with minimal external components. These integrated circuits feature a trimmed oscillator for precise duty cycle control. A temperature compensated reference, high gain Error amplifier, current sensing comparator, and a high current totem pole output ideally suited for driving a power MOSFET. Also Included are protective features consisting of input and reference undervoltage lockouts each with hysteresis, cycle-by-cycle current limiting, programmable output deadtime, and latch for single pulse metering. Features *Trimmed Oscillator for Precise Frequency Control *Oscillator Frequency Guaranteed at 250kHz *Current Mode Operation to 500kHz *Automatic Feed Forward Compensation *latching PWM for Cycle-By-Cycle Current Limiting *Internally Trimmed Reference with Undervoltage Lockout *High Current Totem Pole Output *Undervoltage Lockout with Hysteresis *Low Startup and Operating Current Package Dimensions D E GAUGE PLANE Millimeter Min. Max. c A REF. SEATING PLANE b Z L Z SECTION Z - Z b e DIP-8 DIP-8L A A1 A2 b b1 b2 b3 c 0.381 2.921 0.356 0.356 1.143 0.762 0.203 Function Pin1:Compensation Pin2:Voltage Feedback Pin3:Current Sense Pin4:RT/CT Pin5:Ground Pin6:Output Pin7:Vcc Pin8:Vref 0.5334 4.953 0.559 0.508 1.778 1.143 0.356 REF. c1 D E E1 e HE L Millimeter Min. Max. 0.203 0.279 9.017 10.16 6.096 7.112 7.620 8.255 2.540 BSC 10.92 2.921 3.810 Description This pin is the Error Amplifier output and is made available for loop compensation. This is the inverting input of the Error Amplifier. It’s normally connected to the Switching power supply output through a resistor divider. A voltage proportional to inductor current is connected to this input .The PWM uses this information to terminate the output switch conduction. The oscillator frequency and maximum output duty cycle are programmed by connecting resistor RT to Vref and capacitor CT to ground .Operation 500kHz is possible. This pin is the combined control circuitry and power ground. This output directly drives the gate of a power MOSFET. Peak currents up to 1 A are sourced and sunk by this pin. This pin is the positive supply of the control IC. This is the reference output .It provides charging current for capacitor CT through resistor RT. Absolute Maximum Ratings at Ta = 25 Parameter Total power Supply and Zener current Symbol VALUE Unit (ICC+Iz) 30 mA Output current,source or sink(note1) Io 1.0 A Output energy(capacitive load per cycle) W 5.0 J 1/9 ISSUED DATE :2003/05/20 REVISED DATE :2004/09/30B Current sense and voltage feedback inputs Vin -0.3 to 5.5 V Io 10 mA Power Dissipation at Thermal characteristics PD P JA 702 178 mW /W Storage Temperature Range Error Amplifier Output Sink Current Tstg -65 to 150 Operating Junction Temperature TJ +150 Operating ambient Temperature TA 0~+70 Electrical Characteristics (0 Parameter TA 70 ,Vcc=15V[note 2],RT=10k,CT =3.3Nf,unless otherwise specified) SYMBOL Test Conditions Min Typ. Max. Unit Reference Section Output Voltage VREF Tj=25 Line Regulation Regline Vcc=12V to 25V Load Regulation Regload Io=1mA to 20mA Temperature. Stability Ts Total Output Variation VREF Line, Load, Temperature Output Noise Voltage Vn F=10kHz to 10Hz,Tj=25 Long Term Stability S TA=125 ,1000Hrs Output Short Circuit current ISC Oscillator Section Frequency ,Io=1mA Tj=25 TA=0 Tj=25 to 70 (RT =6.2k,CT =1.0nF) Frequency Change with Voltage fosc/ V Vcc=12V to 25V Frequency Change with Temperature fosc/ T TA = 0 Oscillator Voltage Swing(Peak to Peak) VOSC Discharge Current Idischg 4.90 5 5.1 V 2.0 20 mV 3.0 25 0.2 - 4.82 - 5.18 - 50 - V - 5 - mV -85 -180 mA 49 52 55 250 275 0.2 1.0 48 225 56 0.5 KHz % % 1.6 to 70 V -30 to 70 Tj=25 TA = 0 mV mV/ V 7.8 7.6 8.3 8.8 8.8 mA 2.42 2.50 2.58 V -0.1 -2.0 Error Amplifier Section Voltage Feedback Input VFB Vo =2.5V Input Bias Current IIB VFB=5.0V Open Loop Voltage Gain AVOL Vo=2V to 4V 65 90 dB Unity Gain Bandwidth BW Tj=25 0.7 1.0 MHz Power Supply Rejection Ratio PSRR Vcc=12V to 25V 60 70 dB Output Sink Current Isink Vo=1.1V,VFB=2.7V 2.0 12 mA Output Source Current Isource Vo=5.0V,VFB=2.3V -0.5 -1.0 mA Output Voltage Swing High State VoH VFB=2.3V,RL =15K to GND 5.0 6.2 V Output Voltage Swing Low State Current Sense section VOL VFB=2.7V,RL =15K to Vref Current Sense Input Voltage gain Av (Note 3,4) (Note 3) Maximum Current Sense Input Threshold Vth PSRR Power Supply Rejection Ratio IIB Propagation Delay Tplh(in/out) Current Sense Input to Output VOL Isink=20mA Output Low Voltage Output High Level Output Voltage with UVLO Activated 0.8 1.1 V 2.85 3.0 3.15 V/V 0.9 1.0 1.1 VCC= 12 to 25V (Note 3) Input Bias Current 70 Isink=200mA VOH VOL A V dB -2 -10 A 150 300 ns 0.1 0.4 V 1.6 2.2 V Isource=20mA 13 13.5 Isource=200mA 12 13.4 V V VCC=6.0V,Isink=1.0mA 0.1 1.1 V Output Voltage Rise Time (UVLO) tr Tj=25 ,CL=1nF 50 150 ns Output Voltage Fall Time tr Tj=25 ,CL=1nF 50 150 ns 2/9 ISSUED DATE :2003/05/20 REVISED DATE :2004/09/30B Under-Voltage Lockout Section Startup Threshold Vth Min. Operating Voltage After Turn-on(VCC) VCC(min) 14.5 16 17.5 V 8.5 10 11.5 V 94 96 PWM Section Maximum Duty Cycle DC(MAX) Minimum Duty Cycle DC(MIN) % 0 % Total Device Power Startup Supply Current ICC+IC VCC=14V 0.3 0.5 mA Power Operating Supply Current ICC+IC Note 2 12 17 mA Power Supply Zener Voltage Vz ICC=25mA 30 36 V Note 1: Maximum Package power dissipation limits must be observed. Note 2: Adject Vcc above the Startup threshold before setting to 15V. Note 3: This parameter is measured at the latch trip point with VFB=0V. Note 4: Comparator gain is defined as:: AV V Output Compensation V Current Sense Input Characteristics Curve 3/9 ISSUED DATE :2003/05/20 REVISED DATE :2004/09/30B 4/9 ISSUED DATE :2003/05/20 REVISED DATE :2004/09/30B 5/9 ISSUED DATE :2003/05/20 REVISED DATE :2004/09/30B Application Information 6/9 ISSUED DATE :2003/05/20 REVISED DATE :2004/09/30B 7/9 ISSUED DATE :2003/05/20 REVISED DATE :2004/09/30B 8/9 ISSUED DATE :2003/05/20 REVISED DATE :2004/09/30B Important Notice: All rights are reserved. Reproduction in whole or in part is prohibited without the prior written approval of GTM. GTM reserves the right to make changes to its products without notice. GTM semiconductor products are not warranted to be suitable for use in life-support Applications, or systems. GTM assumes no liability for any consequence of customer product design, infringement of patents, or application assistance. Head Office And Factory: Taiwan: No. 17-1 Tatung Rd. Fu Kou Hsin-Chu Industrial Park, Hsin-Chu, Taiwan, R. O. C. TEL : 886-3-597-7061 FAX : 886-3-597-9220, 597-0785 China: (201203) No.255, Jang-Jiang Tsai-Lueng RD. , Pu-Dung-Hsin District, Shang-Hai City, China TEL : 86-21-5895-7671 ~ 4 FAX : 86-21-38950165 9/9