DC-DC Converter Control Circuits MC34063A OUTPUT SWITCH CURRENT IN EXCESS OF 1.5A 2% REFERENCE ACCURACY LOW QUIESCENT CURRENT:2.5mA(TYP.) OPERATING FROM 3V TO 40V REQUENCY OPERATION TO 100KHz ACTIVE CURRENT LIMITING 8 SOP/ 8 DIP PIN Configulation DESCRIPTION The MC34063A series is a monolithic control circuit delivering the main functions for DC-DC voltage converting. The device contains an intermal 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 devices series is designed for Step-Down, Step-Up and Voltage-lnverting applications. Switch 1 Collector Switch 2 Emitter 8 Drive Collector 7 Ipk Sense Timing 3 Capacitor 6 Vcc Ground 5 - Input Comparator 4 ORDERING INFORMATION Device MC34063AD MC34063AN Package 8 SOP 8 DIP BLOCK DIAGRAM Drive Collector 8 s Q Q2 1 Switch Collector 2 Switch Emitter 3 Timing Capacitor 4 GND Q1 R Ipk Sense 7 Ipk Oscillator Vcc 6 Comparator 1.25V Reference Regulator + Comparator lnverting input 5 HTC 1 DC-DC Converter Control Circuits MC34063A ABSOLUTE MAXIMUM RATINGS SYMBOL Vcc Vir VSWC VSWE VCE Vdc Idc Isw Ptot Top Tstg PARAMETER Power Supply Voltage Comparator input Voltage Range Switch Collector Voltage Switch Emitter Voltage (VSWC=40V) Switch Collector to Emitter Voltage Driver Collector Voltage Driver Collector Current Switch Current Power Dissipation at Tamb=25(for Plastic Package ) (for SOIC Package ) Operating Ambient Temperature Range VALUE 50 -0.3 to 40 40 40 40 40 100 1.5 1.25 0.625 0 to 70 Storage Temperature Range -40 to 150 UNIT V V V V V V A W 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 Rthi-amb Thermal Resistance Junction-ambient (*) Max DIP-8 100 SO-8 160 UNIT /w * ( ) This Value depends from thermal design of PCB on which the device is mounted. CONNECTION DIAGRAM (top view) SWC 1 8 IPK TC VCC 4 5 PIN NO 1 2 3 4 5 6 7 8 DRC SWE GND PIN CONNECTIONS CII SC11080 SYMBOL SWC SWE TC GND CII Vcc IPK DRC NAME AND FUNCTION Switch Collector Switch Emitter Timing Capactor Ground Comparator lnverting lnput Voltage Supply IPK Sense Voltage Driver Collector HTC 2 DC-DC Converter Control Circuits MC34063A ELECTRICAL CHARACTERISTICS( Refer to the test circuits, VCC=5V, Ta=TLOW to THIGH, unless otherwise specified, see note 2) OSCILLATOR SYMBOL FOSC Ichg Idischg Idischg/Ichg Vipk(sense) PARAMETER Frequency Charge Current Discharge Current Discharge to Charge Current Ratio Current Limit Sense Voltage TEST CONDITIONS MIN. o Vpin5= 0 V ,CT= 1nF ,Ta= 25 C 24 o 24 VCC= 5 to 40V ,Ta= 25 C o 140 VCC= 5 to 40V ,Ta= 25 C o 5.2 Pin 7= VCC ,Ta= 25 C o 250 Ichg= Idischg ,Ta= 25 C TYP. 33 33 200 6.2 300 MAX. UNIT 42 KHz 42 260 7.5 350 TEST CONDITIONS ISW= 1A ,Pins 1,8 connected TYP. 1 MAX. UNIT 1.3 V OUTPUT SWITCH SYMBOL PARAMETER VCE(sat) Saturation Voltage, Darlington connection VCE(sat) Saturation Voltage hFE IC(off) DC Current Gain Collector Off-State Current ISW= 1A ,Rpin8= 82 to VCC, Forced ~ 20 ISW= 1A, VCE= 5V, Ta= 25oC VCE= 40V MIN. 50 0.45 0.7 V 120 0.01 100 COMPARATOR SYMBOL PARAMETER Vth Threshold Voltage Regline IIB Threshold Voltage Line Regulation Input Bias Current TEST CONDITIONS Ta= 25oC Ta= TLOW to THIGH VCC= 3 to 40V VIN= 0V MIN. TYP. 1.225 1.25 1.21 1 -5 MAX. UNIT 1.275 V 1.29 V 5 -400 TYP. 2.5 MAX. UNIT 4 TOTAL DEVICE SYMBOL PARAMETER ICC Supply Current VSTART-UP Start-up Voltage(note 4) TEST CONDITIONS MIN. VCC= 5 to 40V, CT=1 Pin7= VCC ,Vpin5>Vth, Pin2=GND Remaining pins open for MC34063A Ta= 25oC ,CT=1 ,Pin5= 0V for MC34063A 2.1 V Notes: 1) Maximum package power dissipation limit must be observed. 2) TLOW= 0oC, THIGH= 70oC 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 of output current switch= I COUTPUT/(ICDRIVER-1* )10 * Current less due to a built in 1K antileakage resistor. 4) Start-up Voltage is the minimum Power Supply Voltage at which the internal oscillator begains to work. HTC 3 DC-DC Converter Control Circuits MC34063A TYPICAL ELECTRICAL CHARACTERISTICS Output Switch ON-OFF Time vs Oscillator Emitter Follower Configuration Output Saturation Voltage vs Emitter Current Timing Capacitor VCE(sat) (V) Ton Toff () 1.75 VCC=5V Pin1,7,8=VCC Pins3,5=GND Ta=25 1.70 1.65 200 150 1.60 VCC=5V Pin7=VCC Pin5=GND Ta=25 Ton 100 1.55 1.50 Toff 50 1.45 1.40 0 0 400 1200 800 IE() Common Emitter Configuration Output Switch Saturation Voltage vs Collector Current VCE(sat) (V) 0.1 0.01 CT() 1 Darlington Configuration Collector Emitter Saturation Voltage (VCE(sat) ) vs Temperature VCE(sat) () Darlington Connection 1.0 1000 0.8 950 VCC=5V Pin7=VCC Pins2,3,5=GND Ta=25 0.6 0.4 0.2 850 800 0 400 IC=1A 900 Forced =20 0 VCC=5V 800 1200 750 -40 1C() 0 80 120 TJ() Current Limit Sense Voltage Voltage (Vipk) vs Temperature Power Collector Emitter Ssturation Voltage (VCE(sat)) vs Temperature Vipk () VCE(sat) () 600 320 VCC=5V 550 40 MC34063A IC=1A 310 500 300 450 290 400 280 VCC=5V 350 -40 0 40 80 120 270 -40 TJ() Ichg=Idischg 0 40 80 120 TJ() HTC 4 DC-DC Converter Control Circuits MC34063A TYPICAL ELECTRICAL CHARACTERISTICS (Continued) Reference Voltage vs Temperature Bias Current vs Temperature Vref (V) IBias () 1.265 10 VCC=5V CII to GND VCC=5V 1.260 8 1.255 6 1.250 4 1.245 2 1.240 -40 0 40 80 120 0 -40 TJ() Supply Current vs Temperature ICC ICC () 5 4.0 VCC=5V CT=1 80 120 TJ() TJ= 25 CT= 1 3.5 3 3.0 2 2.5 1 2.0 0 -40 40 Supply Current vs Input Voltage () 4 0 1.5 0 40 80 120 0 TJ() 10 20 30 40 Vin(V) HTC 5 DC-DC Converter Control Circuits MC34063A TYPICAL APPLICATION CIRCUIT Step-Up Converter L1 170H R3 1 8 180 DRC SWC Ipk SWE 7 Rsc 2 6 Vcc TC CII GND D1 BYV10-40 3 0.22 5 VIN 12V + C2 100 4 C3 VOUT 1.5 25V/175 MC34063A R1 R2 2.2K + C1 44K 330 Step-Down Converter 1 8 DRC SWC 7 Rsc Ipk 0.33 SWE 6 Vcc TC CII GND 5 VIN 25V + C2 100 BYV10-40 2 D1 3 L 4 C3 220H 470 MC34063A R1 R2 1.2K 3.5K + C1 VOUT 5V/0.5A 470 HTC 6 DC-DC Converter Control Circuits MC34063A Step-Up With External NPN Switch 8 VOUT 1 S Q2 Q + Q1 R 2 7 Rsc VIN 3 Ipk Oscillator 6 comparator 1.25V + 4 Reference - Regulator 5 Voltage Inverting Converter 1 8 DRC SWC 7 R3 L1 2 Ipk SWE 0.22 90H 6 3 Vcc TC 5 VIN 4.5V to 5V + C2 100 R2 D1 4 CII GND BYV10-40 C3 1.5 MC34063A R1 VOUT 8.2K 953 C1 + -12V /100 1000 HTC 7 DC-DC Converter Control Circuits MC34063A Step-Down With External NPN Switch 8 1 S Q Q2 Q1 R 2 7 Rsc VOUT 3 Ipk Oscillator + 6 VIN comparator 1.25V + - 4 Reference Regulator 5 Step-Down With External PNP Switch 8 1 S Q Q2 Q1 R + VOUT 2 7 Rsc VIN 3 Ipk Oscillator 6 comparator + - 1.25V 4 Reference Regulator 5 HTC 8 DC-DC Converter Control Circuits MC34063A Voltage Inverting With External NPN Switch 8 1 S Q Q2 Q1 R 2 7 Rsc Ipk Oscillator 6 VIN VOUT 3 + comparator 1.25V + - 4 Reference Regulator 5 Voltage Inverting With External PNP Saturated Switch 8 1 S Q2 Q VOUT Q1 R + 2 7 Ipk Oscillator Rsc VIN 6 3 comparator + - 1.25V Reference 4 Regulator 5 HTC 9 DC-DC Converter Control Circuits MC34063A Dual Output Voltage + +12V GND 8 + 1 S Q Q2 -12V Q1 R 2 7 Rsc Ipk Oscillator comparator 6 VIN 3 1.25V + - 4 Reference Regulator 5 Higher Output Power, Higher Input Voltage + Isolated from input +VOUT -VOUT 8 + 1 S Q R 2 7 VIN Rsc Ipk Oscillator 6 3 comparator 1.25V + - Reference 4 Regulator 5 HTC 10