MC34063A Boost type Adjustable 3V~36V 1.5A DC-DC Converter IC DIP-8

MC34063A Boost Type Adjustable 3V~36V 1.5A DC-DC Converter IC SOP-8 is a highly versatile monolithic control circuit that enables designers to construct buck (step-down), boost (step-up), and inverting DC-DC converters efficiently. This IC integrates all the necessary functions for creating simple, regulated DC power supplies, making it a foundational component in power electronics. Consequently, the MC34063A minimizes external component count while offering a wide input voltage range and an internal 1.5 A power switch. Therefore, you can use this device to design a cost-effective and flexible power management solution, especially for battery-operated systems where stepping up the voltage or achieving reliable negative voltage generation is crucial.

Key Features:

• High Versatility: The MC34063A supports step-down (Buck), step-up (Boost), and voltage-inverting topologies, offering maximum design flexibility.
• Wide Input Voltage Range: The device operates reliably from an input voltage as low as 3.0 V up to 40 V, accommodating various battery chemistries and power sources.
• Integrated Power Switch: Features an internal NPN power transistor with a peak current limit of 1.5 A, simplifying the external drive circuitry.
• Adjustable Output Voltage: Utilize two external resistors to set the output voltage from 1.25 V up to the limits defined by the topology and component choice.
• Current Limiting Protection: Includes an on-chip current limit circuit, providing essential protection for the internal switch and connected components.

Technical Specifications:

• Input Voltage Range (V_in): 3.0 V to 40 V DC
• Maximum Output Current (I_out): Up to 1.5 A (limited by internal switch peak current, I_pk)
• Switch Current Limit (I_pk): 1.5 A maximum
• Reference Voltage (V_ref): 1.25 V (±2%)
• Switching Frequency (f): Adjustable from 100 Hz to 100 kHz (Set by external timing capacitor C_T)
• Quiescent Current (I_Q): Typically 4 mA
• Operating Temperature Range: −40°C to +85°C

Mechanical Specifications:

• Package Type: DIP-8 (Small Outline Package, Surface Mount)
• Mounting: Surface Mount Technology (SMT)
• Lead Material: Copper Alloy, Solder Plated
• Moisture Sensitivity Level (MSL): Typically MSL 1

Dimensions:

• Body Length: ≈ 4.9 mm
• Body Width: ≈ 3.9 mm
• Height: ≈ 1.5 mm
• Lead Pitch: 1.27 mm (Standard for DIP-8)
• Pads/Pins: 8

Pinout and Wiring:

• Pin 1 (Switch Collector): Connects to the inductor and power diode for power transfer.
• Pin 2 (Switch Emitter): Connects to ground through the current sense resistor (R_sc).
• Pin 3 (Timing Capacitor C_T): Connects the external capacitor that determines the oscillator frequency.
• Pin 4 (GND): Connects the IC ground reference.
• Pin 5 (Comparator Inverting Input): Connects the feedback voltage from the output via a voltage divider network (R1 and R2) to regulate the output voltage.
• Pin 6 (V_CC): Input voltage supply (V_in) for powering the internal control circuits.
• Pin 7 (Driver Collector): Connects to V_CC or an external driver source for higher current applications.
• Pin 8 (Current Sense): Connects across the sense resistor (R_sc) to monitor the peak current.

Datasheet Reference:

• Download ON Semiconductor MC34063A DC-DC Converter Datasheet

Commonly Used in:

• Battery-Powered Devices: Essential for stepping up low battery voltages (e.g., single Li-ion cells) to required system voltages (e.g., 5V or 12V).
• Automotive Electronics: Used for non-critical voltage regulation due to its wide input voltage tolerance.
• Small Display Drivers: Providing the higher voltages needed to drive OLED or LCD bias circuitry.

Applications:

• Portable Equipment: Creating efficient, small-scale power supplies for consumer electronics.
• Negative Voltage Generation: Furthermore, designers utilize the MC34063A’s inverting topology to generate stable negative rails for analog circuitry.
• LED Lighting Drivers: Used to regulate current and voltage for low-to-medium power LED strings in various lighting solutions.
• USB Power Supplies: Converting battery voltage to the required 5 V output for charging or powering USB devices.

Equivalent Models:

• LM2577 (Texas Instruments): A high-current step-up regulator, though it is less flexible and often packaged differently.
• NCP3063 (Onsemi): A pin-compatible and functionally identical alternative offered by Onsemi.
• KA34063A (Fairchild/ON Semiconductor): A common cross-reference part number that shares the exact core functionality and specifications.

Package Includes:

• 1 x MC34063A Boost Type Adjustable DC-DC Converter IC DIP-8