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STMicroelectronics MC34063ABD
- Part No.:
- MC34063ABD
- Manufacturer:
- STMicroelectronics
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MC34063ABD.pdf
- Description:
- IC REG BUCK BOOST ADJ 1.5A 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,720
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Product details
Overview
MC34063ABD from STMicroelectronics is a monolithic DC-DC converter control circuit in SO-8 package, featuring 1.5 A output switch current, 2% reference voltage accuracy (1.25 V), and operation from 3 V to 40 V input. It supports step-up, step-down, and inverting topologies with internal oscillator up to 100 kHz and active current limiting - used in industrial power supplies and battery-powered instrumentation.
For engineers reviewing the MC34063ABD datasheet, MC34063ABD pinout, MC34063ABD application, or MC34063ABD equivalent, key selection criteria include its Darlington-compatible output stage, IPK sense threshold of 300 mV, thermal resistance (RthJA = 160 °C/W), and -40 °C to +85 °C operating ambient range for AB-grade reliability.
Technical Context
The MC34063ABD integrates a temperature-compensated 1.25 V reference, comparator, duty-cycle-controlled oscillator, driver, and high-current Darlington switch. Its oscillator frequency (24–42 kHz typical) is set by an external timing capacitor and depends on charge/discharge current ratio (IDISCHG/ICHG = 6.2 typ.).
Current limiting is implemented via IPK sense pin (Pin 7) with 300 mV threshold; saturation voltage is 1.3 V (Darlington) or 0.7 V (forced-β configuration). The device operates across three topologies using only four external components: inductor, capacitor, diode, and two resistors for feedback.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output switch current | 1.5 A max - supports ≥500 mA continuous output in step-down mode with margin |
| Reference voltage | 1.25 V ±2% - enables precise output regulation via R1/R2 divider without trimming |
| Supply voltage range | 3 V to 40 V - accommodates wide-input 12 V/24 V industrial rails and single-cell LiFePO₄ |
| Oscillator frequency | 24–42 kHz typ. - balances efficiency vs. size; avoids audible noise and EMI peaks |
| Quiescent current | 2.5 mA typ. - minimizes no-load power loss in always-on battery systems |
| IPK sense voltage | 300 mV typ. - sets current limit with 0.3 Ω sense resistor for 1 A trip point |
| VCE(sat) (Darlington) | 1.3 V @ 1 A - defines conduction loss and thermal rise in high-current step-up designs |
Pinout & Package
MC34063ABD is housed in a surface-mount SO-8 package (5.00 × 4.00 mm, 1.27 mm pitch), RoHS-compliant and ECOPACK® certified.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 SWC | Switch collector | High-side output node for Darlington or external NPN; connects to inductor in step-up |
| 2 SWE | Switch emitter | Emitting node of internal switch; tied to GND in standard step-down configuration |
| 3 TC | Timing capacitor | Connects external CT to set oscillator frequency; discharge current dominates timing |
| 4 GND | Ground reference | Power and signal return; must be low-impedance for stable current sensing |
| 5 CII | Comparator inverting input | Feedback node for output voltage regulation; referenced to 1.25 V internal reference |
| 6 VCC | Power supply input | Primary supply rail (3–40 V); powers internal circuitry and drives external switch base |
| 7 IPK | Current limit sense | Sense input for peak switch current; 300 mV threshold triggers cycle-by-cycle limiting |
| 8 DRC | Driver collector | Open-collector output for driving external PNP/NPN; enables higher-power configurations |
Key Features
| Feature | Design Value |
|---|---|
| Dual-mode oscillator control | Charge/discharge current ratio (6.2 typ.) ensures stable frequency over VCC and temperature |
| Configurable output topology | Single IC supports step-up, step-down, and inverting converters with shared BOM |
| Integrated Darlington switch | 1.5 A capability eliminates need for external switch in ≤5 W applications |
| Low-startup voltage | 2.1 V minimum start-up enables operation from single Li-ion or NiMH cells |
| Thermal shutdown protection | Junction temperature limit of 150 °C prevents latch-up during overload or poor heatsinking |
Applications
| Industrial Power Supply | Battery-Powered Instrumentation |
|---|---|
|
Use Scenario: 24 V input converted to regulated 5 V for PLC I/O modules with variable load. IC Role / Device Role / Timing Role: Primary DC-DC controller managing step-down conversion, current limiting, and oscillator timing. Use Value: 80% efficiency at 500 mA output reduces thermal stress in enclosed enclosures without forced air. |
Use Scenario: Portable multimeter powered by two AA alkaline cells (1.8–3.2 V) requiring stable 3.3 V for MCU and ADC. IC Role / Device Role / Timing Role: Step-up controller enabling operation down to 1.8 V input while maintaining regulation. Use Value: 2.5 mA quiescent current extends battery life beyond 200 hours in sleep mode. |
| Automotive Body Control Module | LED Driver for Indicator Panels |
|
Use Scenario: 12 V vehicle battery supplying isolated 5 V logic rail for door lock controllers. IC Role / Device Role / Timing Role: Inverting converter generating negative bias for CAN transceiver interface. Use Value: -12 V output at 100 mA with 58% efficiency meets EMC requirements without added filtering. |
Use Scenario: Constant-current LED string driver in dashboard backlighting using 12 V supply. IC Role / Device Role / Timing Role: Step-down controller with external MOSFET switch regulating average LED current. Use Value: IPK sense pin enables accurate 350 mA LED current control with ±5% tolerance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar DC-DC controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2574HVSX-5.0 | Fixed 5 V output, 0.5 A switch, 52 kHz fixed frequency, no IPK sense pin | Limited to step-down only; lacks adjustable current limit and topology flexibility | Select when fixed-output, lower-cost, and simpler layout outweigh configurability needs |
| TPS54202DR | 2 A integrated FET, 4.5–28 V input, 500 kHz switching, current-mode control | Higher efficiency (>90%), smaller inductors, but requires external compensation and lacks inverting support | Select for compact, high-efficiency step-down where board space and thermal performance are critical |
Compared with LM2574HVSX-5.0 and TPS54202DR, MC34063ABD offers unique topology versatility and current-sense programmability at the cost of lower switching frequency and integration - ideal for cost-sensitive, multi-rail legacy designs requiring field-proven robustness.
Availability
MC34063ABD is available at Aetrix Electronics and suitable for industrial power supplies, battery-powered instrumentation, automotive body control modules, and LED indicator drivers requiring stable component supply across extended temperature ranges.
Supply support for MC34063ABD includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power ICs, sensors, and analog devices for industrial, automotive, and consumer markets.
The MC34063 series belongs to ST's legacy analog power management portfolio, engineered for rugged, low-cost DC-DC conversion in resource-constrained embedded systems where reliability and long-term availability are prioritized over ultra-high efficiency.
FAQ
What is the maximum achievable output current using MC34063ABD in step-down configuration?
In step-down mode with proper heatsinking and 25°C ambient, MC34063ABD delivers up to 500 mA continuously at 5 V output from 25 V input, based on 80% typical efficiency and 1.3 V VCE(sat). Peak switch current remains within 1.5 A limit, but sustained >400 mA requires attention to SO-8 thermal resistance (160 °C/W) and PCB copper area.
Can MC34063ABD drive an external MOSFET instead of using the internal switch?
Yes - Pin 8 (DRC) provides an open-collector driver output capable of sinking ≥100 mA, allowing direct connection to the gate of an external N-channel MOSFET. This configuration bypasses the internal Darlington switch, enabling higher output power and reduced conduction loss, especially above 5 W.
How does the IPK pin function, and what resistor value sets a 1.2 A current limit?
The IPK pin compares voltage across an external sense resistor to a 300 mV internal threshold. To set 1.2 A limit, use RSC = 0.3 V / 1.2 A = 0.25 Ω. This resistor connects between SWE (Pin 2) and ground, and the IPK pin monitors its voltage drop during each switching cycle.
Is MC34063ABD suitable for automotive applications requiring AEC-Q100 qualification?
No - MC34063ABD is not AEC-Q100 qualified. It is rated for -40 °C to +85 °C operation (AB grade), but lacks automotive-specific stress testing, failure-in-time (FIT) reporting, and PPAP documentation. For automotive use, consider ST's AEC-Q100 qualified alternatives like the L5973AD.
MC34063ABD Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Step-Up, Step-Down
- Output Configuration:
- Positive or Negative
- Topology:
- Buck, Boost
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 1.25V
- Voltage - Output (Max):
- 38V
- Current - Output:
- 1.5A (Switch)
- Frequency - Switching:
- 33kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
MC34063ABD FAQ
1.How can I place an order for MC34063ABD through Aetrix?
Please submit a Request for Quotation (RFQ) for MC34063ABD on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MC34063ABD reliable?
The price and inventory of MC34063ABD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC34063ABD is usually 5 days.
3.What payment methods are accepted for MC34063ABD?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC34063ABD transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC34063ABD?
MC34063ABD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC34063ABD order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MC34063ABD?
For technical support, including MC34063ABD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC34063ABD requirements.
6.How does Aetrix verify that MC34063ABD is sourced from the original manufacturer or authorized distributors?
All MC34063ABD products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MC34063ABD meets industry standards.
7.What is the process for return or replacement of MC34063ABD?
All MC34063ABD units undergo pre-shipment inspection (PSI). If there is an issue with MC34063ABD, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MC34063ABD part is unused and in its original packaging.
Return procedure for MC34063ABD:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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