TL494 LINEAR INTEGRATED CIRCUIT VOLTAGE MODE PWM CONTROL CIRCUIT DESCRIPTION The Contek TL494 incorporates all the functions required in the construction of a pulse-width modulation switching circuit. Designed primarily for switching power supply control or DCDC convectors, it offers the systems engineer the flexibility to tailor control circuitry to its own application. SOP-16 FEATURES *Complete PWM power control circuitry *Uncommitted outputs for 200 mA sink or source current *Output control selects single ended or push pull operation *Internal circuitry prohibits double pulses over total range *Easy synchronization DIP-16 ABSOLUTE MAXIMUM RATINGS (Unless otherwise noted all is over operating free air temperature range) PARAMETER Supply Voltage(note 1) Amplifier Input Voltage Collector Output Voltage Collector Output Current Continuous Total Dissipation at(or for below) 25 C Free Air Temperature(note 2) Operating Temperature Range Storage Temperature Range Lead Temperature 1.6mm from Case for 60 Sec. SYMBOL VALUE UNIT VCC VI VO ICO PD 41 VCC+0.3 41 250 1000 V V V mA mW Topr Tstg Tcase 0 TO 70 -65 TO 150 300 C C C note 1: All voltage values, except differential voltages are with respect to the network ground terminal. note 2:For operation above 25 C free-air temperature, the dissipation derates with 9.2mW/ C. Contek Microelectronics Co.,Ltd. CONTEK http://www.contek-ic.com E-mail:sales@contek-ic.com 1 TL494 LINEAR INTEGRATED CIRCUIT BLOCK DIAGRAM Input control Pulse Steering Flip-Flop 6 5 8 C1 RT CT 13 Q Q1 Q Q2 T oscillator 9 E1 11 C2 10 E2 dead time comparator 12 4 Vref dead time control 5V reference regulation PWM comparator 14 Vcc 0.7mA 1 16 7 2 15 GND Error Amplifier Error Amplifier 3 RECOMMENDED OPERATING CONDITIONS PARAMETER Supply Voltage Amplifier Input Voltage Collector Output Voltage Collector Output Current(each Transistor) Current into Feedback Timing Capacitor Timing Resistor Oscillator Frequency Operating Free-Air Temperature SYMBOL Vcc Vi Vo Ic If CT RT fosc Ta VALUE UNIT MIN MAX 7 -0.3 40 Vcc-2 40 200 0.3 10000 500 300 70 0.47 1.8 1 0 V V V mA mA nF kW kHz C ELECTRICAL CHARACTERISTICS (Over recommended operating free-air temperature range,VCC=15V,f=1kHz,Unless otherwise specified) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT Reference Section Output Voltage Input Regulation Output Regulation Output Voltage Change with Temperature Short-Circuit Output Current Io=1mA Vcc=7V to 40V Io=1 to 10mA DTA=MIN to MAX(note 2) 4.75 5 2 1 0.2 5.25 25 15 1 V mV mV % Vref=0 35 mA CT=0.01mF,R T=120kW 10 kHz Oscillator Section Frequency Contek Microelectronics Co.,Ltd. CONTEK http://www.contek-ic.com E-mail:sales@contek-ic.com 2 TL494 LINEAR INTEGRATED CIRCUIT PARAMETER TEST CONDITIONS Standard Deviation of Frequency MIN All Values of Vcc CT, RT, TA constant Vcc=7v to 40V,Ta=25 C CT=0.01mF,R T=12kW,DTA=MIN to MAX Frequency Change with Voltage Frequency Change with Temperature TYP MAX UNIT 10 % 0.1 12 % % Amplifier Section Input Offset Voltage Input Offset Current Input Bias Current Common-Mode Input Voltage Range Open-Loop Voltage Amplification Unity-Gain Bandwidth Common-Mode Rejection Ratio Output Sink Current(pin 3) Error Error Vo(pin 3)=2.5V Vo(pin 3)=2.5V Vo(pin 3)=2.5V Vcc=7V to 40 V DVo=3V, Vo=0.5V to 3.5V Error Output source Current(pin 3) Vcc=40V,T A=25 C VID=-15mV to -5V V(pin 3)=0.5V VID=15mV to -5V V(pin 3)=3.5V 2 25 0.2 -0.3 to Vcc-2 70 65 0.3 10 250 1 95 800 80 0.7 mV nA mA V dB kHz dB mA -2 mA Output Section Collector off-state current Emitter off-state Current Collector -emitter Saturation Voltage Commonemitter EmitterFollower Output Control Input Current VCE=40V,Vcc=40V VCC=VC=40V,V E=0 VE=0,Ic=200mA 2 1.1 100 -100 1.3 Vc=15V,I E=-200mA 1.5 2.5 Vi=Vref mA mA V 3.5 mA -2 -10 3 3.3 mA % V 4 0.7 4.5 V mA 10 mA Dead Time Control Section Input bias (pin 4) Maximum duty cycle, each output Input threshold Voltage(pin 4) Vi=0 to 5.25V VI(pin 40=0 Zero duty Cycle Maximum duty cycle 45 0 PWM comparator Section Input Threshold Voltage(pin 3) Input Sink Current (pin 3) Zero Duty cycle Vpin 3= 0.7V 0.3 Total Device Standby Supply Current Vcc=15V pin 6 at Vref,all other Inputs and outputs open Vcc=40V Average supply current Vpin 4=2V 6 9 7.5 15 mA Switching Characteristics,Ta=25 C Output Voltage Rise Time Common-emitter configuration 100 200 Output Voltage Fall Time 25 100 Output Voltage Rise Time Emitter-follower configuration 100 200 Output Voltage Fall Time 40 100 note 1:All typical Values except for temperature coefficient are at Ta=25 C. note 2:For conditions shown as MIN or MAX, use appropriate value under recommended operating conditions. note 3:Duration of the short-circuit should not exceed one second. Contek Microelectronics Co.,Ltd. CONTEK http://www.contek-ic.com E-mail:sales@contek-ic.com ns ns ns ns 3 TL494 LINEAR INTEGRATED CIRCUIT note 4: Standard deviation is a measure of the statistical distribution the mean as derived from the formula : N 2 (xn-x) n=1 s= SN-1 TEST CIRCUIT Vcc=15V Contek TEST INPUTS 12kW 4 DEAD-TIME 3 FEEDBACK 6 RT 5 CT 2W 150 W 12 Vcc 1 0.01 mF C1 8 E1 9 2W 150 W OUTPUT 1 C2 11 E2 10 OUTPUT 2 2 ERROR AMPLIFIER 16 15 13 OUTPUT CONTROL 50kW Vref OUTPUT 14 GND 7 VOLTAGE at C1 VOLTAGE at C2 VOLTAGE at CT DEAD-TIME CONTROL INPUT THRESHOLD VOLTAGE THRESHOLD VOLTAGE FEEDBACK FIG 1. OPERATIONAL TEST CIRCUIT AND WAVEFORMS Contek Microelectronics Co.,Ltd. CONTEK http://www.contek-ic.com E-mail:sales@contek-ic.com 4 TL494 LINEAR INTEGRATED CIRCUIT ERROR AMPLIFIER 1 Vin FEEDBACK TERMINAL 2 16 Vref 15 ERROR AMPLIFIER FIG 2. AMPLIFIER CHARACTERISTICS Vcc 90% EACH OUTPUT CIRCUIT EACH OUTPUT CIRCUIT Q 90% 68W 90% 90% Vc Q 15pF Vcc 10% Ve 10% tr 68W 15pF 10% tf FIG. 3 COMMON-EMITTER CONFIGURATION tr tf 10% FIG. 4 EMITTER -FOLLOWER CONFIGURATION PIN CONFIGURATIONS NONINV INPUT 1 16 NONINV INPUT INV INPUT 2 15 INV INPUT FEEDBACK 3 14 Vref 13 OUTPUT CONTROL DEAD-TIME CONTROL 4 Contek TL494 CT 5 12 Vcc RT 6 11 C2 GND 7 10 E2 C1 8 9 E1 Contek Microelectronics Co.,Ltd. CONTEK http://www.contek-ic.com E-mail:sales@contek-ic.com 5 TL494 LINEAR INTEGRATED CIRCUIT TYPICAL PERFORMANCE CHARACTERISTICS 10 100 5 Vcc=15V Ta=0~70 X C Vcc=15V DV=3V Ta=25 X C 10 10 4 Voltage Amplification (dB) Oscillator Frequency (Hz) 80 CT=0.001 mF CT=0.01 mF 3 CT=0.1 mF 2 10 10 CT=1 mF 1 10 60 40 20 0 3 10 4 10 5 10 6 RT(Timing Resistance) ( W ) FIG 5. Oscillator Frequency and Frequency Variation Vs Timing Resistance 2 10 10 3 10 4 5 10 6 Fig.6 Amplifier Voltage Amplification Contek Microelectronics Co.,Ltd. CONTEK 10 Frequency (Hz) http://www.contek-ic.com E-mail:sales@contek-ic.com 6