The ON Semiconductor MC34063A series of buck boost inverting switching regulators designed for step-down, step-up and voltage-inverting applications.
These are monolithic ICs which contain a wide range of functionality required for DC-DC converters. This functionality includes:
- Internal temperature compensated reference
- Comparator
- Controlled duty cycle oscillator with an active current limit circuit
- Driver
- High current output switch
The MC34063A ICs are suitable for fan controllers and DC-DC power supplies. They offer a wide input voltage of -0.3 to +40 Vdc, which makes the MC34063A suitable for a wider range of applications.

• Temperature range: 0 to +70 °C
• Low standby current
• Input voltage: 3-40 V
• Adjustable current limit
• Adjustable output voltage
• Frequency operation: to 100kHz
• Accuracy: precision 2% reference

Versions Available:
(516-5095) MC34063AP1G - PDIP-8
(125-0038) MC34063AP1G - PDIP-8 - tube of 50
(103-5076) MC34063ADR2G - SOIC-8 - reel of 2500
(689-9948) MC34063ADR2G - SOIC-8
(184-4265) MC34063ADG - SOIC-8 - tube of 98

Operation from 3.0 V to 40 V Input
Low Standby Current
Current Limiting
Output Switch Current to 1.5 A
Output Voltage Adjustable
Frequency Operation to 100 kHz
Precision 2% Reference
4x4mm DFN package option
Wide input voltage range usable for many applications
<100uA Collector Off-State Current
Adjustable current limit provides improved protection
Large 1.5A peak current capability provides up to ∼1A of average current output
External resistor divider for various output voltage options
Optimize frequency for size or efficiency
Accurate system level performance
Exposed pad package allows for higher output current and improved thermal performance
Applications
For Higher Switching Frequency See NCP3063
For Dedicated ENABLE Pin and Higher Switching Frequency See NCP3064
Fan Controller
DC-DC Power Supply
For DFN package see MC33063MNTXG