MC34063A

MC34063A DESCRIPTION DC-TO-DC Converter Control Circuits PIN CONFIGURATION Switch Collector Switch Emitter Timing Capacitor GND 1 2 3 4 8 7 6 5 Diver Collector IPK Sense VCC Comparator Inverting Input The MC34063A is a monolithic control circuit containing the primary functions required for DC-to-DC converters. The device consists of an internal temperature compensated reference, comparator, controlled duty cycle oscillator with an active current limit circuit, driver and high current output switch. MC34063A is specifically designed to be incorporated in Step-Down, Step-Up and VoltageInverting applications with a minimum number of external components. (Top View) FEATURES Operation from -0.3V to 40V Input Low Standby Current Current Limiting Output Switch Current to 1.5A Output Voltage Adjustable Frequency Operation to 42kHz Precision 2% Reference APPLICATION DC-DC Converter ORDERING INFORMATION Temperature Range Package SOP8L SOP8L DIP8L Orderable Device MC34063ADG MC34063ADRG MC34063APG Package Qty 75Units/Tube 2500Units/Tape 50Units/Tube 0°C to +70°C Pb-Free 1 MC34063A SCHEMATIC DIAGRAM 8 Drive Collector DC-TO-DC Converter Control Circuits 1 Switch Collector SQ R 7 Ipk Sense Ipk Oscillator GT 6 VCC 3 Timing Capacitor 100 Q2 Q1 2 Switch Emitter + Comparator _ 5 Comparator Inverting Input 1,25V Reference Regulator 4 GND (Bottom View) Figure 1. Representative Schematic Diagram ABSOLUTE MAXIMUM RATINGS Parameter Power Supply Voltage Comparator Input Voltage Range Switch Collector Voltage Switch Emitter Voltage (VPin1 = 40 V) Switch Collector to Emitter Voltage Driver Collector Voltage Driver Collector Current (Note 1) Switch Current Power Dissipation, TA = 25°C D Package P Package Thermal Resistance, TA = 25°C D Package P Package Symbol VCC VIR VC(switch) VE(switch) VCE(switch) VC(driver) IC(driver) ISW PD RθJA TJ TA Tstg Value 40 −0.3 to +40 40 40 40 40 100 1.5 625 1.25 160 100 +150 0 to +70 −65 to +150 °C/W °C °C °C Unit V V V V V V mA A mW W Operating Junction Temperature Operating Ambient Temperature Range Storage Temperature Range 2 MC34063A ELECTRICAL CHARACTERISTICS Parameter OSCILLATOR Frequency Charge Current Discharge Current Discharge to Charge Current Ratio Current Limit Sense Voltage fosc Ichg I dischg Idischg/Ichg Vlpk(sense) Symbol DC-TO-DC Converter Control Circuits (Vcc = 5.0V, TA=0 to +70°C, unless otherwise specified) Test Conditions Min Typ Max Unit 33 33 42 42 kHz μA μA V Pin5 =0V,C T =1.0nF,T A = 25°C 24 V CC = 5 .0V to 40V, T A = 2 5°C 24 V CC = 5 .0V to 40V, T A = 2 5°C 140 Pin7 to V CC , T A =25°C I chg = I dischg , T A = 2 5°C 5.2 250 200 260 6.2 7.5 300 350 mV OUTPUT SWITCH (Note 3) Saturation Voltage, VCE(sat) Darlington Connection Saturation Voltage, Darlinton Connection I SW = 1 .0A, Pins 1, 8 connected ISW = 1.0A, Forced β = 20 RPin 8 = 82Ω to VCC I SW = 1 .0A, V CE = 5.0V, T A = 2 5°C V CE = 4 0V 1.0 1.3 V V VCE(sat) hFE IC(off) 0.45 0 .7 50 75 40 1 00 DC Current Gain Collector Off-State Current COMPARATOR Threshold Voltage Threshold Voltage Line Regulation Input Bias Current T OTAL DEVICE Supply Current μA V th Reg line IIB T A = 2 5°C T A = T low t o T high V CC = 3 .0V to 40V V in = 0 V V CC = 5 .0V to 40V, C T = 1 0nF, V pin7 = V CC , V Pin5 > V th , Pin 2 = GND, Remaining pins open 1.225 1.25 1.275 1.21 1.4 1.29 5.0 V mV nA - 2 0 -400 ICC 2.5 4.0 mA NOTE 1: Maximum package power dissipation limits must be observed NOTE 2: Low duty cycle pulse techniques are used during test to maintain juction temperature as close to ambient temperature as possible 3 MC34063A Assembly Information: DC-TO-DC Converter Control Circuits CHIP APPEARANCE CHIP SIZE CHIP THICKNESS 1 8 7 BONDING PAD DIMENSION 1a 1b 2a 2b 3 4 5 6 7 8 SCRIBE LINE WIDTH TOP METAL BACK METAL WAFER SIZE SWITCH COLLECTOR SWITCH EMITTER TIMING CAPACITOR GROUND COMPARATOR INVERTING INPUT 1,18 × 1,27 mm 460 ± 20 μm 90 × 90 μm 90 × 90 μm 90 × 90 μm 90 × 90 μm 90 × 90 μm 90 × 90 μm 90 × 90 μm 90 × 90 μm 96 μm Al – 100 mm 2 3 4 5 6 Vcc Ipk SENCE DRIVER COLLECTOR 4 MC34063A ton-off.OUTPUT SWITCH ON-OFF TIME(μS) 1000 500 200 100 50 20 10 5.0 2.0 1.0 DC-TO-DC Converter Control Circuits TYPICAL PERFORMANCE CHARACTERISTICS V CC =5.0V Pin7=V CC Pin5=GND T A =25°C t on VOSC,OSOCILLATOR VOLTAGE(V) 200 mV / DIV VCC=5.0V Pins1,5,8=Open Pin7=VCC CT=1.0μF Pin2=GND TA=25°C 10μS / DIV 1.1 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 VCC=5.0V Pin7=Vcc Pins 2,3,5=GND TA = 25ºC Forcedβ = 20 Darlington Connection t off 0.01 0.02 0.05 0.1 0 .2 0.5 1.0 2.0 5.0 10 CT,OSCILLATOR TIMING CAPACITOR(nF) Figure 3. Timing Capacitor Waveform Figure 2. Output Switch On−Off Time vs. Oscillator Timing Capacitor 1.8 VCE(sat),SATURATION VOTAGE(V) 1.7 1.6 1.5 1.4 1.3 1.2 1.1 1.0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 VCC=5.0V Pins1,7,8=Vcc Pins3,5=GND TA = 25ºC VCE(sat),SATURATION VOTAGE(V) IE, EMITTER CURRENT(A) Figure 4. Emitter Follower Configuration Output Saturation Voltage vs. Emitter Current IC, COLLECTOR CURRENT(A) Figure 5. Common Emitter Configuration Output Switch Saturation Voltage vs. Collector Current 400 3.6 Vcc=5.0V Ichg=Idischg VIPK(sense),CURRENT LIMIT ICC,SUPPLY CURRENT(mA) 380 360 3.2 2.8 2.4 2.0 1.6 1.2 0.8 0.4 0 0 5.0 10 15 20 25 30 35 40 CT=1.0nF Pin7=Vcc Pin2=GND SENSE VOLTAGE(V) 340 320 300 280 260 240 220 200 -55 -25 0 25 50 75 100 125 TA,AMBIENT TEMPERATURE(°C) Figure 6. Current Limit Sense Voltage vs. Temperature VCC,S UPPLY VOLTAGE(V) Figure 7. Standby Supply Current vs. Supply Voltage 5 MC34063A TYPICAL APPLICATION DC-TO-DC Converter Control Circuits L1 170μH R3 180Ω 8 1 DRC SWC 2 SWE 3 D1 BYV10-40 7 Ipk RSG 0.22Ω VIN 12V C2 100μF + 6 VCC TC 5 CII GND 4 VOUT C3 1.5nF R1 2.2kΩ R2 47kΩ C3 330μF + Figure 8. Step−Up Converter For VOUT=28V Parameter Line Regulation Load Regulation Output Ripple Efficiency Test Conditions VIN = 8 to 16 V, IO = 175 mA VIN = 12 V, IO = 75 to 175 mA VIN = 12 V, IO = 175 mA VIN = 12 V, IO = 175 mA Result(Typ) 30 10 300 89 Unit mV mV mV % 6 MC34063A DC-TO-DC Converter Control Circuits TYPICAL APPLICATION(CONTINUED) 8 1 DRC SWC BYV10-40 2 Ipk SWE D1 3 7 RSC 0.33Ω 6 VCC TC 5 Vin C2 100μF + CII GND 4 L1 220μH C3 470pF R2 1.2kΩ R1 3.6kΩ C1 470μF + Figure 9. Step−Down Converter For VOUT = 5V Parameter Line Regulation Load Regulation Output Ripple Efficiency ISC Test Conditions VIN = 15 to 25 V, IO = 500 mA VIN = 25 V, IO = 50 to 500mA VIN = 25 V, IO = 500 mA VIN = 25 V, IO = 500mA VIN = 25 V, Rload = 0.1 Ω Result(Typ) 5 30 100 80 1.2 Unit mV mV mV % A 7 MC34063A DC-TO-DC Converter Control Circuits TYPICAL APPLICATION(CONTINUED) 8 1 DRC SWC L1 2 Ipk SWE 90μH 3 TC 7 RSC 0.22Ω 6 VCC VIN 4.5 to 6V C2 100μF + 5 CII GND 4 D1 BYV10-40 C3 1.5nF R2 8.2kΩ R1 953kΩ C1 1000μF + VOUT -12V / 100mA Figure 10. Voltage Inverting Converter For VOUT = -12V Patameter Line Regulation Load Regulation Output Ripple Efficiency ISC Test Conditions VIN = 4.5 to 6 V, IO = 100 mA VIN = 5 V, IO = 10 to 100mA VIN = 5 V, IO = 100 mA VIN = 5 V, IO = 100mA VIN = 5 V, Rload = 0.1 Ω Result(Typ) 15 20 230 58 0.9 Unit mV mV mV % A 8 MC34063A DC-TO-DC Converter Control Circuits TYPICAL APPLICATION(CONTINUED) 8 1 SQ R Q2 + Q1 VOUT 2 7 RSC Ipk Oscillator 3 VIN 6 + Comparator 1.25V Reference Regulator 4 _ 5 Figure 11. Step-up with External NPN Switch 8 1 SQ R Q2 Q1 2 7 RSC Ipk Oscillator 3 VOUT VIN 6 + Comparator 1.25V Reference Regulator + 4 _ 5 Figure 12. Step-down with External NPN Switch 9 MC34063A DC-TO-DC Converter Control Circuits TYPICAL APPLICATION(CONTINUED) 8 1 SQ R Q2 Q1 VOUT 2 7 RSC Ipk Oscillator + 3 VIN 6 + Comparator 1.25V Reference Regulator 4 _ 5 Figure 13. Step-down with External PNP Switch 8 1 SQ R Q2 Q1 2 7 RSC Ipk Oscillator 3 VOUT VIN 6 + Comparator 1.25V Reference Regulator 4 _ 5 + Figure 14. Voltage Inverting with External NPN Switch 10 MC34063A DC-TO-DC Converter Control Circuits TYPICAL APPLICATION(CONTINUED) 8 1 SQ R Q2 Q1 VOUT 2 7 Ipk Oscillator + RSC VIN 6 3 + Comparator 1.25V Reference Regulator 4 _ 5 Figure 15. Voltage Inverting with External PNP Saturated Switch +12V + GND + 8 1 SQ R Q2 Q1 -12V 2 7 RSC Ipk Oscillator 3 VIN 6 + Comparator 1.25V Reference Regulator 4 _ 5 Figure 16. Dual Output Voltage 11 MC34063A DC-TO-DC Converter Control Circuits TYPICAL APPLICATION(CONTINUED) + +VOUT Isolated from input -VOUT + 8 1 SQ R Q2 Q1 2 VIN 7 RSC 6 Ipk Oscillator 3 + Comparator 1.25V Reference Regulator 4 _ 5 Figure 17. Higher Output Power, Higher Input Voltage 12 MC34063A CALCULATION DC-TO-DC Converter Control Circuits Table 1 Design Formula Table Calculation Step-Up Vout + VF - Vin(min) Vin(min) - Vsat Step-Down Vout + VF Vin(min) - Vsat - Vout Voltage-Inverting |Vout | + VF Vin - Vsat ton/toff (ton+toff)max toff ton CT Ipk(switch) RSC L(min) CO 1 f ton + toff ton/toff + 1 (ton + toff) - toff 4.0×10 -5 ton ton 2Iout(max) toff + 1 1 f ton + toff ton/toff + 1 (ton + toff) - toff 4.0×10 -5 ton 2Iout(max) 1 f ton + toff ton/toff + 1 (ton + toff) - toff 4.0×10 -5 ton ton 2Iout(max) toff + 1 ( ) ( ) 0.3 I PK(switch) 0.3 IPK(switch) (Vin(min) - Vsat - Vout) ton(max) Ipk(switch) Ipk(switch)(ton + toff) 8Vripple(p-p) 0.3 IPK(switch) (Vin(min) - Vsat) ton(max) Ipk(switch) ≈ Ioutton Vripple(p-p) (Vin(min) - Vsat) ton(max) Ipk(switch) ≈ Ioutton Vripple(p-p) Vsat=Saturation voltage of the output switch. VF=Forward voltage drop of the output rectifier. The following power supply characteristics must be chosen: Vin=Nominal input voltage. Vout=Desired output voltage. Vout =1.25(1+R2/R1) Iout=Desired output current. fmin=Minimum desired output switching frequency at the selected values of Vin and Io Vripple(pp)=Desired peak-to-peak output ripple voltage.In prictice,the calculated capacitor value will need to be increased due to its equivalent series resistance and board layout. The ripple should be kept to a low value since it will directiy affect the line and load regulation. 13 MC34063A PHYSICAL DIMENSIONS SOP8L A3 A1 A2 DC-TO-DC Converter Control Circuits 1 4 B1 R2 B 2 A 3 R1 B2 C1 C2 C C3 D1 D Symbol A A1 A2 A3 B B1 B2 C C1 C2 Dimension(mm) Max Min 4.95 0.37 5.15 0.47 1.27(TYP) 0.41(TYP) 5.80 6.20 4.00 3.80 5.0(TYP) 1.30 0.55 0.55 1.50 0.65 0.65 Symbol C3 C4 D D1 R1 R2 1 2 3 4 Dimension(mm) Min Max 0.20 0.20(TYP) 1.05(TYP) 0.40 0.60 0.07(TYP) 0.07(TYP) 17 (TYP) 13 (TYP) 4 (TYP) 12 (TYP) 0.05 14 C4 MC34063A DIP8L A DC-TO-DC Converter Control Circuits D2 1 2 B 3 D1 D C C2 C3 C1 A5 A3 A1 A4 A2 C4 Symbol A A1 A2 A3 A4 A5 B C C1 Dimension(mm) Min 9.30 Max 9.50 0.53 2.54(TYP) 0.66(TYP) 0.99(TYP) 6.3 6.5 7.20(TYP) 3.30 3.50 Symbol C2 C3 C4 D D1 D2 1 2 3 Dimension(mm) Min Max 0.5(TYP) 3.3(TYP) 1.57(TYP) 8.20 0.20 7.62 8.80 0.35 7.87 8 (TYP) 8 (TYP) 5 (TYP) 1.524(TYP) 0.39 15