MC34063A DC-TO-DC Converter Control Circuits DESCRIPTION PIN CONFIGURATION 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. Switch Collector 1 8 Diver Collector Switch Emitter 2 7 IPK Sense Timing Capacitor 3 6 VCC 5 Comparator Inverting Input GND 4 (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 0°C to +70°C Package SOP8L SOP8L Pb-Free DIP8L 1 Orderable Device Package Qty MC34063ADG MC34063ADRG 75Units/Tube 2500Units/Tape MC34063APG 50Units/Tube MC34063A DC-TO-DC Converter Control Circuits SCHEMATIC DIAGRAM 1 8 Switch Collector Drive Collector Q2 S Q Q1 R 7 100 Ipk Sense 2 Switch Emitter Ipk Oscillator GT 6 3 Timing Capacitor VCC + 1,25V Reference Regulator Comparator _ 5 4 GND Comparator Inverting Input (Bottom View) Figure 1. Representative Schematic Diagram ABSOLUTE MAXIMUM RATINGS Parameter Symbol Value Unit Power Supply Voltage VCC 40 V Comparator Input Voltage Range VIR −0.3 to +40 V Switch Collector Voltage Switch Emitter Voltage (VPin1 = 40 V) VC(switch) VE(switch) 40 40 V V Switch Collector to Emitter Voltage VCE(switch) 40 V VC(driver) IC(driver) 40 100 V mA ISW 1.5 A 625 mW 1.25 W Driver Collector Voltage Driver Collector Current (Note 1) Switch Current Power Dissipation, TA = 25°C D Package PD P Package Thermal Resistance, TA = 25°C D Package RθJA P Package 160 100 °C/W Operating Junction Temperature Operating Ambient Temperature Range TJ +150 °C TA 0 to +70 °C Storage Temperature Range Tstg −65 to +150 °C 2 MC34063A DC-TO-DC Converter Control Circuits ELECTRICAL CHARACTERISTICS (Vcc = 5.0V, TA=0 to +70°C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit OSCILLATOR Frequency fosc V Pin5 =0V,C T =1.0nF,T A = 25°C 24 33 42 kHz Charge Current Ichg V CC = 5.0V to 40V, T A = 25°C 24 33 42 μA I dischg V CC = 5.0V to 40V, T A = 25°C 140 200 260 Idischg/Ichg Pin7 to V CC , T A =25°C 5.2 6.2 Vlpk(sense) I chg = I dischg , T A = 25°C 250 300 350 Discharge Current Discharge to Charge Current Ratio Current Limit Sense Voltage OUTPUT SWITCH (Note 3) Saturation Voltage, VCE(sat) Darlington Connection Saturation Voltage, Darlinton Connection VCE(sat) DC Current Gain hFE Collector Off-State Current IC(off) 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 = 25°C 7.5 mV 1.3 V 0.45 0.7 V 1.0 50 μA 75 V CE = 40V 40 T A = 25°C 1.225 1.25 1.275 100 μA COMPARATOR Threshold Voltage V th Threshold Voltage Line Regulation Reg line Input Bias Current T A = T low to T high 1.21 1.29 V V CC = 3.0V to 40V 1.4 IIB V in = 0V -20 -400 nA ICC V CC = 5.0V to 40V, C T = 10nF, V pin7 = V CC , V Pin5 > V th , Pin 2 = GND, Remaining pins open 2.5 mA 5.0 mV TOTAL DEVICE Supply Current 4.0 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 DC-TO-DC Converter Control Circuits Assembly Information: CHIP APPEARANCE CHIP SIZE CHIP THICKNESS 8 1 1a 1b 2a 2b 7 3 BONDING PAD DIMENSION 2 3 4 5 6 4 5 6 7 8 SCRIBE LINE WIDTH TOP METAL BACK METAL WAFER SIZE 4 SWITCH COLLECTOR SWITCH EMITTER TIMING CAPACITOR GROUND COMPARATOR INVERTING INPUT Vcc Ipk SENCE DRIVER COLLECTOR 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 MC34063A 500 V CC =5.0V Pin7=V CC Pin5=GND T A =25°C 200 100 50 t on 20 10 5.0 t off 2.0 1.0 0.01 0.02 0.05 0.1 0.2 0.5 1.0 2.0 5.0 VCC=5.0V Pins1,5,8=Open Pin7=VCC CT=1.0μF Pin2=GND TA=25°C 10 10μS / DIV CT,OSCILLATOR TIMING CAPACITOR(nF) Figure 2. Output Switch On−Off Time vs. Oscillator Timing Capacitor Figure 3. Timing Capacitor Waveform 1.7 1.6 1.5 1.4 VCC=5.0V Pins1,7,8=Vcc Pins3,5=GND TA = 25ºC 1.3 1.2 1.1 1.0 0 0.2 VCE(sat),SATURATION VOTAGE(V) 1.1 1.8 VCE(sat),SATURATION VOTAGE(V) 200 mV / DIV 1000 VOSC,OSOCILLATOR VOLTAGE(V) ton-off.OUTPUT SWITCH ON-OFF TIME(μS) DC-TO-DC Converter Control Circuits TYPICAL PERFORMANCE CHARACTERISTICS 1.0 0.9 Darlington Connection 0.8 0.7 0.6 VCC=5.0V Pin7=Vcc Pins 2,3,5=GND TA = 25ºC 0.5 0.4 Forcedβ = 20 0.3 0.2 0.1 0 0 0.4 0.6 0.8 1.0 1.2 1.4 1.6 IC, COLLECTOR CURRENT(A) IE, EMITTER CURRENT(A) Figure 4. Emitter Follower Configuration Output Saturation Voltage vs. Emitter Current Figure 5. Common Emitter Configuration Output Switch Saturation Voltage vs. Collector Current 3.6 380 ICC,SUPPLY CURRENT(mA) VIPK(sense),CURRENT LIMIT 400 Vcc=5.0V Ichg=Idischg 360 SENSE VOLTAGE(V) 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 340 320 300 280 260 240 220 3.2 2.8 2.4 2.0 1.6 1.2 0.4 0 200 -55 -25 0 25 50 75 100 125 TA,AMBIENT TEMPERATURE(°C) Figure 6. Current Limit Sense Voltage vs. Temperature CT=1.0nF Pin7=Vcc Pin2=GND 0.8 0 5.0 10 15 20 25 30 35 40 VCC,S UPPLY VOLTAGE(V) Figure 7. Standby Supply Current vs. Supply Voltage 5 MC34063A DC-TO-DC Converter Control Circuits TYPICAL APPLICATION L1 170μH R3 8 1 DRC SWC Ipk SWE 180Ω 7 RSG 6 2 VCC TC D1 BYV10-40 3 0.22Ω VIN 5 12V C2 100μF CII GND 4 + VOUT C3 1.5nF R1 R2 2.2kΩ 47kΩ C3 330μF + Figure 8. Step−Up Converter For VOUT=28V Parameter Test Conditions Result(Typ) Unit Line Regulation VIN = 8 to 16 V, IO = 175 mA 30 mV Load Regulation VIN = 12 V, IO = 75 to 175 mA mV Output Ripple VIN = 12 V, IO = 175 mA 10 300 Efficiency VIN = 12 V, IO = 175 mA 89 % 6 mV MC34063A DC-TO-DC Converter Control Circuits TYPICAL APPLICATION(CONTINUED) 8 1 DRC SWC BYV10-40 7 RSC 0.33Ω Ipk SWE D1 6 5 Vin C2 100μF 2 VCC CII TC GND 3 4 + L1 220μH C3 470pF R2 R1 1.2kΩ 3.6kΩ C1 470μF + Figure 9. Step−Down Converter For VOUT = 5V Result(Typ) Unit VIN = 15 to 25 V, IO = 500 mA 5 mV Load Regulation VIN = 25 V, IO = 50 to 500mA mV Output Ripple VIN = 25 V, IO = 500 mA 30 100 Efficiency VIN = 25 V, IO = 500mA VIN = 25 V, Rload = 0.1 Ω 80 % 1.2 A Parameter Line Regulation ISC Test Conditions 7 mV MC34063A DC-TO-DC Converter Control Circuits TYPICAL APPLICATION(CONTINUED) 8 1 DRC SWC Ipk SWE L1 7 RSC 0.22Ω 90μH 6 5 VIN 4.5 to 6V C2 100μF 2 3 VCC CII TC GND + 4 D1 BYV10-40 C3 1.5nF R2 R1 8.2kΩ 953kΩ VOUT -12V / 100mA C1 1000μF + Figure 10. Voltage Inverting Converter For VOUT = -12V Result(Typ) Unit VIN = 4.5 to 6 V, IO = 100 mA 15 mV Load Regulation VIN = 5 V, IO = 10 to 100mA mV Output Ripple VIN = 5 V, IO = 100 mA 20 230 Efficiency VIN = 5 V, IO = 100mA VIN = 5 V, Rload = 0.1 Ω 58 % 0.9 A Patameter Line Regulation ISC Test Conditions 8 mV MC34063A DC-TO-DC Converter Control Circuits TYPICAL APPLICATION(CONTINUED) 8 1 VOUT Q2 S Q + Q1 R 2 7 Ipk Oscillator RSC 6 VIN + Comparator 3 1.25V Reference Regulator 4 _ 5 Figure 11. Step-up with External NPN Switch 8 1 S Q Q2 Q1 R 2 7 Ipk Oscillator RSC 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 Q2 S Q Q1 R VOUT 2 + 7 Ipk Oscillator RSC 6 VIN 3 1.25V Reference Regulator + Comparator 4 _ 5 Figure 13. Step-down with External PNP Switch 8 1 Q2 S Q Q1 R 2 7 Ipk Oscillator RSC 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 Q2 S Q VOUT Q1 R 2 + 7 Ipk Oscillator RSC 3 VIN 6 1.25V Reference Regulator + Comparator 4 _ 5 Figure 15. Voltage Inverting with External PNP Saturated Switch +12V + GND + 8 1 S Q Q2 Q1 R 2 7 Ipk Oscillator RSC VIN 6 + Comparator 3 1.25V Reference Regulator 4 _ 5 Figure 16. Dual Output Voltage 11 -12V MC34063A DC-TO-DC Converter Control Circuits TYPICAL APPLICATION(CONTINUED) + +VOUT Isolated from input -VOUT + 8 1 S Q Q2 Q1 R 2 7 VIN RSC 3 Ipk Oscillator 6 + Comparator 1.25V Reference Regulator 4 _ 5 Figure 17. Higher Output Power, Higher Input Voltage 12 MC34063A DC-TO-DC Converter Control Circuits CALCULATION Table 1 Design Formula Table Calculation ton/toff Step-Up Step-Down Vout + VF - Vin(min) Vin(min) - Vsat 1 f (ton+toff)max Voltage-Inverting Vout + VF Vin(min) - Vsat - Vout |Vout | + VF Vin - Vsat 1 f 1 f toff ton + toff ton/toff + 1 ton + toff ton/toff + 1 ton + toff ton/toff + 1 ton (ton + toff) - toff (ton + toff) - toff (ton + toff) - toff CT 4.0×10 -5 ton ton 2Iout(max) toff + 1 Ipk(switch) RSC L(min) CO ( I ) 2Iout(max) 0.3 0.3 PK(switch) IPK(switch) (Vin(min) - Vsat) ton(max) Ipk(switch) ≈ 4.0×10 -5 ton Ioutton Vripple(p-p) (Vin(min) - Vsat - Vout) ton(max) Ipk(switch) Ipk(switch)(ton + toff) 8Vripple(p-p) 4.0×10 -5 ton ton 2Iout(max) toff + 1 ( ) 0.3 IPK(switch) (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 DC-TO-DC Converter Control Circuits PHYSICAL DIMENSIONS SOP8L A3 A1 A2 1 B1 4 B R2 3 2 A R1 C3 C4 C2 C C1 B2 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 14 Dimension(mm) Min Max 0.05 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) MC34063A DC-TO-DC Converter Control Circuits DIP8L A D2 1 B 2 3 D1 C2 C3 C C1 C4 D A5 A3 A4 A1 A2 Symbol A Dimension(mm) Min Max 9.30 9.50 A1 A2 Symbol Min 1.524(TYP) 0.39 Dimension(mm) 0.53 Max C2 0.5(TYP) C3 3.3(TYP) C4 1.57(TYP) A3 2.54(TYP) D 8.20 8.80 A4 0.66(TYP) D1 0.20 0.35 A5 0.99(TYP) D2 7.62 7.87 B 6.3 7.20(TYP) C C1 6.5 3.30 3.50 15 1 8 (TYP) 2 8 (TYP) 3 5 (TYP)