Overview of DC-DC Conversion Control Circuit MC34063
The MC34063 is a monolithic DC-DC converter integrated circuit featuring a temperature-compensated reference voltage source (1.25V), comparator, an oscillator that can effectively limit current and control the operating cycle, driver, and a high-current output switching transistor. With a few additional components, it can be configured to form a step-up, step-down, or inverting DC-DC converter.
Key Features of MC34063 DC-DC Conversion Control Circuit:
Wide working voltage range: 3.0V~36V
Low static current
Both output current limiting and output current protection functions
Output switch current up to 1.5A
Output voltage adjustable
Operating frequency up to 100 KHz
Internal reference voltage accuracy: 2%
DC-DC Conversion Control CircuitMC34063's Absolute Maximum Ratings:
| Parameters | Symbol | Numeric Values | Unit |
| Power Voltage | VCC | 36 | V |
| Comparator Input Voltage Range | VIR | -0.3~36 | |
| Output Collector Voltage | VC(switch) | 36 | |
| Emitter Voltage (VPINI = 40V) | VE(switch) | 36 | |
| Voltage between the collector and emitter of the output tube | VCE(switch) | 36 | |
| Drive Tube Collector Voltage | VC(driver) | 36 | |
| Driver Tube Collector Current | IC(driver) | 100 | mA |
| Output Current | ISW | 1 | A |
| Power Consumption | PD | 1.25 | W |
| Work Environment Temperature | TA | 0~+70 | ℃ |
| Storage Temperature | Tstg | -65~+150 |
DC-DC Conversion Control CircuitElectrical characteristics of MC34063(Vcc=5.0V；TA-0~85°C (unless otherwise specified):
| Characteristics Conditions | Symbol | Minimum Value | Typical Value | Maximum value | Unit |
Oscillation Frequency (VPINS=0V，CT=1μF，TA=25℃) | fosc | 24 | 33 | 42 | KHz |
Charging Current (Vcc=5V~40V,TA=25℃) | Ichg | 24 | 33 | 42 | μA |
Discharge Current (Vcc=5V~40V,TA=25℃) | Idischg | 140 | 200 | 260 | |
Discharge-to-charge current ratio (VPIN7=Vcc,TA=25℃) | Idischg/Ichg | 5.2 | 6.2 | 7.5 | |
| Current Limiter Voltage Sensitivity (Ichg=Idischg, T)A=25℃) | VIPK | 250 | 300 | 350 | mV |
Saturated Pressure Drop (ISW=1A, PINI, 8 Connector) | VCE(sat) | 1 | 1.3 | V | |
Saturated Pressure Drop (ISW=1A,RPIN882Ω to VCC | VCE(sat) | 0.45 | 0.7 | ||
DC Amplification Gain (ISW=1A,VCE=5V,TA=25℃) | hfe | 50 | 120 | ||
Collector leakage current (VCE=40V) | IC(off) | 0.01 | 100 | μA | |
| Threshold Voltage (T)A=25℃) | Vth | 1.23 | 1.25 | 1.27 | V |
| Threshold Voltage (T)A=0~85℃) | 1.21 | 1.25 | 1.29 | ||
Input Bias Current (VIN=0V) | IIB | -40 | -400 | μA | |
Threshold voltage linearity adjustment rate (VCC=3~40V) | Regline | 1.4 | 5 | mV | |
Power Current (VCC=5V~40V,CT=1nF,VPIN7=VCC,VPIN5＞Vth,VPIN2=GND, the rest suspended) | ICC | 2.5 | 4 | mA |
