SPW3842S High Performance Current Mode Elektronische Bauelemente Controlers RoHS Compliant Product Description SOP-8 The SPW3842S 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 min. 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 undervoltages lockouts each with hysteresis, cycle-by-cycle current limiting, proprammable output deadtime, and latch for single pulse metering. 0.19 0.25 0.40 0.90 45 o 0.375 REF 6.20 5.80 0.25 3.80 4.00 1.27 Typ. 0.35 0.49 4.80 5.00 0.10 0.25 1.35 1.75 o 0 o 8 Dimensions in millimeters Features 8 * Low Startup And Operating Current * Automatic Feed Forward Compensation 6 5 3 4 3842 * High Current Totem Pole Output Date Code * Trimmed Oscillator For Precise Frequency Control 7 * Oscillator Frequency Graranteed At 250kHz * Undervoltage Lockout With Hysteresis 1 2 * Current Mode Operation To 500kHz * Internally Trimmed Reference With Undervoltage Lockout * Iatching PWM For Cycle-By-Cycle Current Limiting SOP-8L Function Pin1:Compensation Pin2:Voltage Feedback Pin3:Current Sense Pin4:RT/CT Pin5:Ground Pin6:Output Pin7:Vcc Pin8:Vref http://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A Description This pin is the Error Amplifier output and is made available for loop compensation. rogrammed by This is the inverting input of the Error Amplifier. It’s normally connected to the CT to ground .Operation 500kHz Switching power supply output throughpacitor 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 nts up The oscillator frequency and maximum output duty cycle are programmed by to pacitor CT connecting resistor RT to Vref and capacitor CT to to ground ground..Operation Operation 500kHz 500kHz is possible. This combinedoutput control.Itcircuitry and power ground. Thispin is is thethereference provides charging current for capacitor CT This output directly directly drives drives the the gate gate of of aapower powerMOSFET. MOSFET.Peak Peakcurrents currentsup uptoto This output 1 A are sourced and sunk by this pin. This pin is the positive supply of the control IC. This is the thereference referenceoutput. outputIt .It provides charging current for capacitor This is provides charging current for capacitor CT CT through resistor RT. Any changing of specification will not be informed individual Page 1 of 10 SPW3842S High Performance Current Mode Elektronische Bauelemente Controlers Absolute Maximum Ratings at Ta = 25 Parameter Symbol Total power Supply and Zener current VALUE Unit (ICC+Iz) 30 mA Io 1.0 A Output current,source or sink(note1) Output energy(capacitive load per cycle) W 5.0 Current sense and voltage feedback inputs Vin -0.3 to 5.5 Error Amplifier Output Sink Current J V Io 10 mA Power Dissipation at Thermal characteristics PD P JA 702 178 mW /W Storage Temperature Range 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) 4.90 5 5.1 V 2.0 20 mV 3.0 25 0.2 - 4.82 - 5.18 - 50 - 5 - mV -85 -180 mA 49 52 55 250 275 1.0 48 225 56 Vcc=12V to 25V 0.2 Frequency Change with Temperature fosc/ T TA = 0 0.5 VOSC Idischg to 70 to 70 KHz % % 1.6 Tj=25 TA = 0 V - fosc/ V Discharge Current V -30 Frequency Change with Voltage Oscillator Voltage Swing(Peak to Peak) 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 VOL VFB=2.7V,RL =15K to Vref http://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A 0.8 1.1 A V Any changing of specification will not be informed individual Page 2 of 10 SPW3842S High Performance Current Mode Elektronische Bauelemente Controlers Current Sense section Current Sense Input Voltage gain Av Maximum Current Sense Input Threshold Vth PSRR Power Supply Rejection Ratio (Note 3,4) 2.85 3.0 3.15 (Note 3) 0.9 1.0 1.1 VCC= 12 to 25V (Note 3) Input Bias Current 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 70 Isink=200mA VOH VOL V/V V dB -2 -10 A 150 300 ns 0.1 0.4 V 1.6 2.2 V Isource=20mA 13 13.5 V Isource=200mA 12 13.4 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 Under-Voltage Lockout Section Startup Threshold Vth 14.5 16 17.5 V Min. Operating Voltage After Turn-on(VCC) VCC(min) 8.5 10 11.5 V Maximum Duty Cycle DC(MAX) 94 96 Minimum Duty Cycle DC(MIN) 0 % 0.3 0.5 mA 12 17 mA PWM Section % Total Device Power Startup Supply Current ICC+IC Power Operating Supply Current ICC+IC Note 2 Power Supply Zener Voltage Vz ICC=25mA VCC=14V 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 ht tp://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A Any changing of specification will not be informed individual Page 3 of 10 SPW3842S Elektronische Bauelemente http://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A High Performance Current Mode Controlers Any changing of specification will not be informed individual Page 4 of 10 SPW3842S Elektronische Bauelemente http://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A High Performance Current Mode Controlers Any changing of specification will not be informed individual Page 5 of 10 SPW3842S Elektronische Bauelemente High Performance Current Mode Controlers Application Information ht tp://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A Any changing of specification will not be informed individual Page 6 of 10 SPW3842S Elektronische Bauelemente http://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A High Performance Current Mode Controlers Any changing of specification will not be informed individual Page 7 of 10 SPW3842S Elektronische Bauelemente http://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A High Performance Current Mode Controlers Any changing of specification will not be informed individual Page 8 of 10 SPW3842S High Performance Current Mode Elektronische Bauelemente http://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A Controlers Any changing of specification will not be informed individual Page 9 of 10 SPW3842S Elektronische Bauelemente http://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A High Performance Current Mode Controlers Any changing of specification will not be informed individual Page 10 of 10