MC34063A MC34063E ® DC-DC CONVERTER CONTROL CIRCUITS ■ ■ ■ ■ ■ ■ OUTPUT SWITCH CURRENT IN EXCESS OF 1.5A 2% REFERENCE ACCURACY LOW QUIESCENT CURRENT: 2.5mA (TYP.) OPERATING FROM 3V TO 40V FREQUENCY OPERATION TO 100KHz ACTIVE CURRENT LIMITING DESCRIPTION The MC34063A/E series is a monolithic control circuit delivering the main functions for DC-DC voltage converting. The device contains an internal temperature compensated reference, comparator, duty cycle controlled oscillator with an active current limit circuit, driver and high current output switch. Output voltage is adjustable through two external resistors with a 2% reference accuracy. Employing a minimum number of external components the MC34063A/E devices series is designed for Step-Down, Step-Up and Voltage-Inverting applications. DIP-8 SO-8 BLOCK DIAGRAM March 2001 1/15 MC34063A/E ABSOLUTE MAXIMUM RATINGS Symbol V CC Parameter Value Unit 50 V Power Supply Voltage -0.3 to 40 V V SWC Switch Collector Voltage 40 V V SWE V ir Comparator Input Voltage Range Switch Emitter Voltage (VSWC = 40V) 40 V V CE Switch Collector toEmitter Voltage 40 V Vdc Driver Collector Voltage 40 V I dc Driver Collector Current 100 mA I SW Switch Current P tot Power Dissipation at Tamb = 25 oC (for Plastic Package) (for SOIC Package) 1.5 A 1.25 0.625 W T op Operating Ambient Temperature Range (for AC and EC SERIES) (for AB SERIES) (for EB SERIES) 0 to 70 - 40 to 85 - 40 to 125 o T st g Storage Temperature Range - 40 to 150 o C C o C o C Absolute Maximum Rating are those values beyond which damage to the device may occur. Functional operation under these condition is not implied. THERMAL DATA Symbol Parameter DIP-8 R thj-amb Thermal Resistance Junction-ambient (*) Max SO-8 100 160 Unit o C/W (*) This value depends from thermal design of PCB on which the device is mounted. CONNECTION DIAGRAM (top view) PIN CONNECTIONS Pin No Symbol Name and Function 1 SWC Switch Collector 2 SWE Switch Emitter 3 TC 4 GND 5 CII Comparator Inverting Input Voltage Supply 6 V CC 7 I pk 8 DRC Timing Capacitor Ground Ipk Sense Voltage Driver Collector ORDERING NUMBERS Type DIP-8 SO-8 SO-8 (tape & reel) MC34063AB (*) MC34063ABN MC34063ABD MC34063ABD-TR MC34063AC (*) MC34063ACN MC34063ACD MC34063ACD-TR MC34063EB MC34063EBN MC34063EBD MC34063EBD-TR MC34063EC MC34063ECN MC34063ECD MC34063ECD-TR (*) The "A" version is not recommended for new designs. 2/15 MC34063A/E ELECTRICAL CHARACTERISTICS (Refer to the test circuits, VCC = 5V, Ta = TLOW to THIGH, unless otherwise specified, see note 2) OSCILLATOR Symbol f OSC I chg I dischg Parameter Frequency Test Conditions Vpin5 = 0 V CT = 1 nF o Ta = 25 C o Min. Typ. Max. Unit 24 33 42 KHz Charge Currernt VCC = 5 to 40 V Ta = 25 C 24 33 42 µA Discharge Current VCC = 5 to 40 V Ta = 25 oC 140 200 260 µA o Idischg /I chg Discharge to Charge Current Ratio Pin 7 = VCC Ta = 25 C 5.2 6.2 7.5 V ipk(sense) Current Limit Sense Voltage Ichg = Idischg Ta = 25 oC 250 300 350 mV Test Conditions Min. Typ. Max. Unit 1 1.3 V 0.45 0.7 V 100 µA OUTPUT SWITCH Symbol Parameter V CE(sat) Saturation Voltage, Darlington Connection ISW = 1 A V CE(sat) Saturation Voltage ISW = 1 A Rpin8 = 82 Ω to VCC, Forced β ~ 20 DC Current Gain ISW = 1 A Collector Off-State Current VCE = 40 V h FE I C(off) Pins 1, 8 connected VCE = 5 V Ta = 25 oC 50 120 0.01 COMPARATOR Symbol V th Reg line II B Parameter Test Conditions Min. Typ. Max. Unit 1.225 1.21 1.25 1.275 1.29 V V VCC = 3 to 40 V 1 5 mV VIN = 0 V -5 -400 nA Typ. Max. Unit VCC = 5 to 40 V CT = 1 nF Pin 7 = VCC Vpin5 > Vth Pin 2 = GND Remaining pins open for MC34063A for MC34063E 2.5 1.5 4 4 mA mA Ta = 25 oC CT = 1 µF for MC34063A for MC34063E 2.1 1.5 Threshold Voltage Ta = 25 oC Ta = TLOW to THIGH Threshold Voltage Line Regulation Input Bias Current TOTAL DEVICE Symbol I CC Parameter Supply Current V START-UP Start-up Voltage (note 4) Test Conditions Min. Pin 5 = 0 V V V NOTES: 1) Maximum package power dissipation limit must be observed. 2) TLOW = 0 oC, THIGH = 70 oC (AC and EC series); TLOW = -40 oC, THIGH = 85 oC (AB series); TLOW = -40 oC, THIGH = 125 oC (EB series). 3) If Darlington configuration is not used, care must be taken to avoid deep saturation of output switch. The resulting switch-off time may be adversely affected. In a Darlington configuration the following output driver condition is suggested: Forced β of output current switch = ICOUTPUT/(ICDRIVER - 1mA*) ≥ 10 * Current less due to a built in 1KΩ antileakage resistor. 4) Start-up Voltage is the minimum Power Supply Voltage at which the internal oscillator begins to work. 3/15 MC34063A/E TYPICAL ELECTRICAL CHARACTERISTICS Emitter Follower Configuration Output Saturation Voltage vs Emitter Current Output Switch ON-OFF Time vs Oscillator Timing Capacitor Common Emitter Configuration Output Switch Saturation Voltage vs Collector Current Darlington Configuration Collector Emitter Saturation Voltage (VCE(sat)) vs Temperature Power Collector Emitter Saturation Voltage (VCE(sat)) vs Temperature Current Limit Sense Voltage Voltage (Vipk) vs Temperature 4/15 MC34063A/E TYPICAL ELECTRICAL CHARACTERISTICS (Continued) Reference Voltage vs Temperature Bias Current vs Temperature Supply Current vs Temperature Supply Current vs Input Voltage 5/15 MC34063A/E TYPICAL APPLICATION CIRCUIT Step-Up Converter Printed Demoboard Symbol Pin Vout 1 GND 2 GND 3 Vin 4 Test Condition (VOUT = 28V) Test Conditions Value (Typ.) Unit 30 mV 10 mV IO = 175 mA 300 mV IO = 175 mA 89 % Line Regulation VIN = 8 to 16V, Load Regulation VIN = 12V, IO = 75 to 175 mA Output Ripple VIN = 12V, Efficency VIN = 12V, 6/15 IO = 175 mA MC34063A/E Step-Down Converter Printed Demoboard Symbol Pin Vout 1 GND 2 GND 3 Vin 4 Test Condition (VOUT = 5V) Test Value (Typ.) Unit IO = 500 mA Conditions 5 mV VIN = 25V, IO = 50 to 500 mA 30 mV Output Ripple VIN = 25V, IO = 500 mA 100 mV Efficency VIN = 25V, IO = 500 mA 80 % ISC VIN = 25V, RLOAD = 0.1Ω 1.2 A Line Regulation VIN = 15 to 25V, Load Regulation 7/15 MC34063A/E Voltage Inverting Converter Printed Demoboard Symbol Pin Vout 1 GND 2 GND 3 Vin 4 Test Condition (VOUT = -12V) Test Value (Typ.) Unit IO = 100 mA Conditions 15 mV VIN = 5V, IO = 10 to 100 mA 20 mV Output Ripple VIN = 5V, IO = 100 mA 230 mV Efficency VIN = 5V, IO = 100 mA 58 % ISC VIN = 5V, RlLOAD = 0.1Ω 0.9 A Line Regulation VIN = 4.5 to 6V, Load Regulation 8/15 MC34063A/E Calculation Parameter ton/toff Step-Up (Discontinuos mode) Step-Down (Continuos mode) Voltage Inverting (Discontinuos mode) Vout + VF − Vin(min) Vin(min) − Vsat Vin(min) − Vsat − Vout Vout + VF | Vout | + VF Vin − Vsat (ton + toff)max CT IPK(switch) RSC CO L(min) 1/f min 1/fmin 1/f min 4.5x10-5 t on 4.5x10 -5 ton 4.5x10 -5 t on 2I out(max) [(t on /t off )+1] 2I out(max) 2I out(max) [(t on /t off )+1] 0.3/I PK(switch) 0.3/I PK(switch) 0.3/IPK(switch) ≅ Iout ton Vripple (p−p) Vin(min) − Vsat ton (max) IPK (switch) IPK (switch) (ton + toff ) 8Vripple (p−p) Vin(min) − Vsat − Vout ton (max) IPK (switch) ≅ Iout ton Vripple (p−p) Vin(min) − Vsat ton (max ) IPK (switch) NOTES: Vsat = Saturation voltage of the output switch VF = Foward 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 = Desired peak to peak output ripple voltage. In practice, the calculaed capacitor value will and to be increased due to its equivalent series resistance and board layout. The ripple voltage should be kept to a low value since it will directly affect the line and load regulation. Step-up With External NPN Switch 9/15 MC34063A/E Step-down With External NPN Switch Step-down With External PNP Switch 10/15 MC34063A/E Voltage Inverting With External NPN Switch Voltage Inverting With External PNP Saturated Switch 11/15 MC34063A/E Dual Output Voltage Higher Output Power, Higher Input Voltage 12/15 MC34063A/E Plastic DIP-8 MECHANICAL DATA mm DIM. MIN. A TYP. inch MAX. MIN. 3.3 TYP. MAX. 0.130 a1 0.7 B 1.39 1.65 0.055 0.065 B1 0.91 1.04 0.036 0.041 b b1 0.028 0.5 0.38 0.020 0.5 D 0.015 0.020 9.8 0.386 E 8.8 0.346 e 2.54 0.100 e3 7.62 0.300 e4 7.62 0.300 F 7.1 0.280 I 4.8 0.189 L Z 3.3 0.44 0.130 1.6 0.017 0.063 P001F 13/15 MC34063A/E SO-8 MECHANICAL DATA mm DIM. MIN. TYP. A a1 inch MAX. MIN. TYP. 1.75 0.1 0.068 0.25 a2 MAX. 0.003 0.009 1.65 0.064 a3 0.65 0.85 0.025 0.033 b 0.35 0.48 0.013 0.018 b1 0.19 0.25 0.007 0.010 C 0.25 0.5 0.010 0.019 5.0 0.188 0.196 6.2 0.228 c1 45 (typ.) D 4.8 E 5.8 0.244 e 1.27 0.050 e3 3.81 0.150 F 3.8 4.0 0.14 0.157 L 0.4 1.27 0.015 0.050 M S 0.6 0.023 8 (max.) 0016023 14/15 MC34063A/E Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. 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