VOLTAGE MODE PWM CONTROL CIRCUIT DESCRIPTION The incorporates all the functions required in the construction of a pulse-width modulation switching circuit. Designed primarily for switching power supply control or DC- DC convectors, it offers the systems engineer the flexibility to tailor control circuitry to its own application. SOP- FEATURES *Complete PWM power control circuitry *Uncommitted outputs for 00 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- ABSOLUTE MAXIMUM RATINGS(Unless otherwise noted all is over operating free air temperature range) PARAMETER SYMBOL VALUE UNIT Supply Voltage(note ) V CC 0 V Amplifier Input Voltage V I V CC +0. V Collector Output Voltage V O 0 V Collector Output Current I CO 0 ma Continuous Total Dissipation at(or for below) P D 000 mw C Free Air Temperature(note ) Operating Temperature Range T opr 0 TO 70 C Storage Temperature Range T stg - TO 0 C Lead Temperature.mm from Case for 0 Sec. T case 0 C note : All voltage values, except differential voltages are with respect to the network ground terminal. note :For operation above C free-air temperature, the dissipation derates with 9.mW/ C.
BLOCK DIAGRAM RT CT oscillator Pulse Steering Flip-Flop T Input control 8 C 9 E C 0 E dead time control dead time comparator PWM comparator V reference regulation 0.7mA Error Amplifier Error Amplifier 7 GND RECOMMENDED OPERATING CONDITIONS PARAMETER SYMBOL VALUE UNIT MIN MAX Supply Voltage 7 0 V Amplifier Input Voltage Vi -0. - V Collector Output Voltage Vo 0 V Collector Output Current(each Transistor) Ic 00 ma Current into Feedback If 0. ma Timing Capacitor CT 0.7 0000 nf Timing Resistor RT.8 00 kω Oscillator Frequency fosc 00 khz Operating Free-Air Temperature Ta 0 70 C ELECTRICAL CHARACTERISTICS (Over recommended operating free-air temperature range,vcc=v,f=khz,unless otherwise specified) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT Reference Section Output Voltage Io=mA.7. V Input Regulation =7V to 0V mv Output Regulation Io= to 0mA mv Output Voltage Change with TA=MIN to MAX(note ) 0. % Temperature Short-Circuit Output Current =0 ma Oscillator Section Frequency CT=0.0µF,RT=kΩ 0 khz
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT Standard Deviation of Frequency All Values of CT, RT, TA 0 % constant Frequency Change with Voltage =7v to 0V,Ta= C 0. % Frequency Change with CT=0.0µF,RT=kΩ, TA=MIN % Temperature to MAX Amplifier Section Input Offset Voltage Error Vo(pin )=.V 0 mv Input Offset Current Vo(pin )=.V 0 na Input Bias Current Vo(pin )=.V 0. µa Common-Mode Input Voltage Range Error =7V to 0 V -0. to - Open-Loop Voltage Amplification Vo=V, Vo=0.V to.v 70 9 db Unity-Gain Bandwidth 800 khz Common-Mode Rejection Ratio Error =0V,TA= C 80 db Output Sink Current(pin ) VID=-mV to -V 0. 0.7 ma V(pin )=0.V Output source Current(pin ) VID=mV to -V V(pin )=.V - ma Output Section Collector off-state current VCE=0V,=0V 00 µa Emitter off-state Current VCC=VC=0V,VE=0-00 µa Collector -emitter Saturation Voltage Commonemitter Emitter- Follower VE=0,Ic=00mA.. V Vc=V,IE=-00mA.. Output Control Input Current Vi=. ma Dead Time Control Section Input bias (pin ) Vi=0 to.v - -0 µa Maximum duty cycle, each output VI(pin 0=0 % Input threshold Voltage(pin ) Zero duty Cycle. V Maximum duty cycle 0 PWM comparator Section Input Threshold Voltage(pin ) Zero Duty cycle. V Input Sink Current (pin ) Vpin = 0.7V 0. 0.7 ma Total Device Standby Supply Current =V pin at,all other Inputs and 0 ma outputs open =0V 9 Average supply current Vpin =V 7. ma Switching Characteristics,Ta= C Output Voltage Rise Time Common-emitter configuration 00 00 ns Output Voltage Fall Time 00 ns Output Voltage Rise Time Emitter-follower configuration 00 00 ns Output Voltage Fall Time 0 00 ns note :All typical Values except for temperature coefficient are at Ta= C. note :For conditions shown as MIN or MAX, use appropriate value under recommended operating conditions. note :Duration of the short-circuit should not exceed one second. V
note : Standard deviation is a measure of the statistical distribution the mean as derived from the formula : σ= ΣN (xn-x) n= N- TEST CIRCUIT =V TEST INPUTS kω 0.0 µf DEAD-TIME RT CT ERROR AMPLIFIER W 0 Ω C 8 E 9 C E 0 W 0 Ω 0kΩ CONTROL GND 7 VOLTAGE at C VOLTAGE at C VOLTAGE at CT DEAD-TIME CONTROL INPUT THRESHOLD VOLTAGE THRESHOLD VOLTAGE FIG. OPERATIONAL TEST CIRCUIT AND WAVEFORMS
Vin ERROR AMPLIFIER TERMINAL ERROR AMPLIFIER FIG. AMPLIFIER CHARACTERISTICS EACH CIRCUIT 8Ω pf 0% tr tf 0% Vc EACH CIRCUIT 8Ω pf 0% tr tf 0% Ve FIG. COMMON-EMITTER CONFIGURATION FIG. EMITTER -FOLLOWER CONFIGURATION PIN CONFIGURATIONS NONINV INPUT NONINV INPUT INV INPUT INV INPUT DEAD-TIME CONTROL CONTROL CT RT C GND 7 0 E C 8 9 E
TYPICAL PERFORMANCE CHARACTERISTICS 0 0 =V Ta=0~70 XC CT=0.00 µf 00 80 =V V=V Ta= XC Oscillator Frequency (Hz) 0 0 0 0 0 CT= µf 0 CT=0.0 µf CT=0. µf RT(Timing Resistance) ( Ω ) 0 0 Voltage Amplification (db) 0 0 0 0 0 0 Frequency (Hz) 0 0 FIG. Oscillator Frequency and Frequency Variation Fig. Amplifier Voltage Amplification Vs Timing Resistance