What Is the MC34063? DC-DC Converter Controller: Pinout and Uses
The MC34063 is a cheap, versatile DC-DC converter control IC. It can be used in buck (step-down), boost (step-up) and inverting topologies. It contains an oscillator, comparator, current limit and a power switch; it runs with a few external parts (inductor, diode, resistors, capacitor). Pinout DIP-8: SWC/SWE/CT/GND/FB/VCC/Ipk/DRC.
The MC34063 is a cheap, versatile DC-DC converter control IC. It can be used in buck (step-down), boost (step-up) and inverting topologies; this makes it a classic for single-chip SMPS. For the concept, see what is a voltage regulator.
What is the MC34063 used for?
Low-power DC-DC converters: 12 V to 5 V (buck), 5 V to 12 V (boost) or generating a negative voltage (inverting). It contains an oscillator, comparator, current limit and a power switch; it runs with a few external parts (inductor, diode, resistors, capacitor).
MC34063 pinout (DIP-8)
| Pin | Function |
|---|---|
| 1 | Switch collector (SWC) |
| 2 | Switch emitter (SWE) |
| 3 | Timing capacitor (CT) |
| 4 | GND |
| 5 | Feedback / comparator input |
| 6 | VCC |
| 7 | Current sense (Ipk) |
| 8 | Driver collector (DRC) |
Specifications
| Parameter | Value |
|---|---|
| Type | DC-DC converter controller (buck/boost/inverting) |
| Input | ~3 V … 40 V |
| Switch current | ~1.5 A (internal) |
| Frequency | ~a few kHz – 100 kHz (set by CT) |
Limitations
- Low frequency → large inductor/capacitor; high current needs an external switch.
- Lower efficiency than modern buck ICs (but flexible and cheap).
Equivalents
- MC34063A / NCV34063: close versions.
- LM2596: a more efficient buck (step-down only).
- MT3608: a ready boost module IC.
Find it in our catalog
Use the MC34063 search.