- MC33063U + 220 L=100uH Ipk_max=1A Ipk CT S R Q Q2 Q1 6 5 8 7 3 4 1 2 switch collector emitter timing capacitor 1.25V reference regulator GND Oscillator Ipk CT drive Sense VCC comparator inverter input + - S R Q Q2 Q1 100 6 5 8 7 3 4 1 2 MC33063U 1N4148 VF=0.6V Rsc 1Ω2 470p 4.80V 39mA @1k2 11.83V 100u 10V 33k Rload 2k2 (5.4mA) 1k2 for 9.9mA 150u 16V 3k9

4.8 Vin 39 mA for 11.83 Vout with load 1k2, without load 3.3 mA Vout 12V Iout 10mA Vin 4.8V Vsat 1V Vf 0.6V L 100uA, 1A Co 47uF ton/toff = (Vout + Vf - Vin) / (Vin - Vsat) = (12 + 0.6 - 4.8) / (4.8 - 1) = 2.052 ton/toff = 2 1/f = (ton + toff) = ton* (1 + ton/toff) CT = ton * 4*10^-5 --> ton = CT/4*10^-5 CT=330p --> ton = 8.25 usec, f = 1 / (ton*(1+ton/toff)) = 1 / (8.25*10^-6*(1+2)) = 40 kHz CT=470p --> ton = 11.75 usec, f = 1 / (ton*(1+ton/toff)) = 1 / (11.75*10^-6*(1+2)) = 28 kHz Ipk = 2 * Iout * (1 + ton/toff) = 2 * 10*10^-3 * (1+2) = 60 mA Rsc = 0.3 / Ipk(switch) for Rsc=1.2Ω --> Ipk = 0.3/1.2 = 250 mA which is below maximum of 1A for the inductor and above needed 57.5mA For 60mA Ipk current Rsc = 0.3/60*10^-3 = 5 Ohm CT=470p, Ipk_switch=60mA, L=xx uH Lmin = ton_max * (Vin - Vsat) / Ipk_switch = 11.75*10^-6 * (4.8 - 1) / 60*10^-3 = 744 uH CT=470p, Ipk_switch=xx mA, L=100 uH Ipk_switch = ton_max * (Vin - Vsat) / L = 11.75*10^-6 * (4.8 - 1) /100*10^-6 = 447 mA CT=270p --> ton = CT / 4*10^-5 = 6.75 usec Ipk_switch = ton_max * (Vin - Vsat) / L = 6.75*10^-6 * (4.85 - 1) /100*10^-6 = 260 mA f = 1 / (ton*(1+ton/toff)) = 1 / (6.75*10^-6*(1+1.875)) = 52 kHz Co = (9 * Iout * ton)/ Vripple (pp) --> Vripple(pp) = (9 * Iout * ton)/ Co = 9*10mA*12usec/47u = 23 mV diode 1N4148, CT 470p : 4.8 Vin 39 mA for 11.83 Vout with load 1k2, without load 3.3 mA

pcb 16x5 front-side 100u 25V MC33063U 100uH 100u 10V +12V out GND +5V A 220 1Ω2 33k 470p 100u 10V 3k9 elco’s aan andere kant IC maakt verbindingen korter +12V out GND +5V in

pcb 16x5 back-side 100uH 100u 10V 25V +5V in +12V out GND MC33063U 1Ω2 220 3k9 33k 1N4148 A 470p 100uH 100u 10V 25V +5V in +12V out GND MC33063U elco’s aan andere kant IC maakt verbindingen korter

pcb 13x8 front-side +5V in 100uH MC33063U 100uF 25V + +12V out GND 220 1Ω2 3k9 100uF 10V MC33063U 33k 100uF 25V + 470p A 1N4148 +12V out GND

pcb 13x8 back-side +5V in 100uH MC33063U 100uF 25V + +12V GND out 10V 1Ω2 220 3k9 A 1N4148 470p MC33063U 100uF 25V + 33k 10V

USB MIC +5V +5V +12V GND 0V GND YELLOW mic BLUE gnd GREEN 12Vin out GND USB 0V GND YELLOW mic MIC BLUE gnd GREEN 12Vin RED ptt red, right USB plug white, left +5V shield 3.5mm 0V green red +12Vout +5V in mic cable PCB gnd yellow blue white gnd connect to 3,5mm plug