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onsemi MC34167T
- Part No.:
- MC34167T
- Manufacturer:
- onsemi
- Package:
- TO-220-5
- Datasheet:
-
MC34167T.pdf
- Description:
- IC REG BUCK BST ADJ 5.5A TO220-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,013
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Product details
Overview
MC34167T from onsemi is a fixed-frequency voltage-mode switching regulator IC designed for step-down, inverting, and step-up/down DC-DC converter topologies. It integrates a 5.0 A output switch, 72 kHz oscillator with on-chip timing, precision 5.05 V ±2% reference, cycle-by-cycle current limiting, and thermal shutdown. It operates from 7.5 V to 40 V input and supports industrial power supplies and automotive auxiliary rails.
For engineers reviewing the MC34167T datasheet, pinout, applications, or equivalent options, key selection considerations include its 5.0 A switch current capability, 0–95% duty cycle range, undervoltage lockout with 5.9 V startup threshold and 0.9 V hysteresis, standby mode reducing supply current to 36 µA, and TO-220 package with heatsink-connected pin 3.
Technical Context
The MC34167T implements voltage-mode PWM control using an internal error amplifier (80 dB gain, 600 kHz unity-gain bandwidth) referenced to a trimmed 5.05 V bandgap. Its oscillator generates a 72 kHz ramp with 4.1 V/2.3 V thresholds, enabling up to 95% duty cycle and blanking during CT discharge to prevent multiple pulses per cycle.
Current protection uses cycle-by-cycle sensing via an internal resistor; the switch current limit is 6.5 A typical, with thermal shutdown activating at ~170 °C. Undervoltage lockout ensures operation only above 5.9 V with 0.9 V hysteresis, and the device enters low-power standby when compensation pin voltage drops below 150 mV.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switch Current Rating | 5.0 A continuous output - enables high-current step-down converters without external MOSFETs |
| Oscillator Frequency | 72 kHz fixed - simplifies EMI filtering and inductor sizing for cost-sensitive industrial designs |
| Reference Voltage | 5.05 V ±2% - provides stable feedback threshold for accurate 5.0 V output regulation with cable-drop compensation |
| Duty Cycle Range | 0% to 95% - supports wide input-to-output voltage ratios in inverting and step-up/down configurations |
| UVLO Threshold | 5.9 V startup / 5.0 V turn-off - prevents erratic operation during brown-out conditions with built-in hysteresis |
| Standby Supply Current | 36 µA at 12 V - enables low-quiescent-power sleep modes in battery-backed or energy-conscious systems |
| Operating Input Range | 7.5 V to 40 V - suitable for 12 V and 24 V automotive and industrial bus applications |
Pinout & Package
MC34167T is housed in a 5-lead TO-220 package (Case 314B), where the metal tab is electrically connected to Pin 3 (GND) and serves as the primary thermal path to the heatsink.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Compensation (Comp) | Output of error amplifier; connects to RC network for loop stability - clamping below 150 mV enables standby mode |
| Pin 2 | Switch Output (SW) | Collector of internal NPN power transistor - drives external inductor; rated for 40 V max and 5.5 A peak |
| Pin 3 | Ground (GND) | Power and signal ground reference; internally tied to heatsink tab - must be low-impedance connection for thermal and noise control |
| Pin 4 | Input Supply (VCC) | Main power input (7.5–40 V); powers internal circuitry and bias networks - feeds UVLO comparator and oscillator |
| Pin 5 | Voltage Feedback (FB) | Inverting input of error amplifier; referenced internally to 5.05 V - used with resistor divider to set output voltage |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 5.0 A Power Switch | Eliminates need for external high-current transistor in ≤5 A step-down/inverting supplies |
| Fixed 72 kHz Oscillator | Reduces BOM count by removing external timing components while enabling predictable EMI spectrum |
| 5.05 V ±2% Precision Reference | Enables 5.0 V output accuracy without trimming, compensating for typical 1% cable drop |
| Cycle-by-Cycle Current Limit | Protects switch under short-circuit or overload without requiring external sense resistors or comparators |
| Thermal Shutdown & UVLO | Prevents latch-up or damage during overtemperature or low-input-voltage conditions - no external supervision needed |
Applications
| Automotive Auxiliary Power Supply | Industrial 5 V Rail Generator |
|---|---|
|
Use Scenario: Generating regulated 5.0 V from a 12 V vehicle battery for infotainment microcontrollers and sensors. IC Role / Device Role / Timing Role: Primary controller in step-down topology; regulates output via PWM duty cycle modulation of internal 5.0 A switch. Use Value: Delivers 5.0 A at 5.0 V with ±0.039% line regulation and 78.9% efficiency at 12 V input - meets automotive transient and thermal requirements. |
Use Scenario: Providing stable 5 V/3 A for PLC I/O modules in factory automation cabinets with 24 V DC input. IC Role / Device Role / Timing Role: Core regulator in fixed-frequency voltage-mode control loop; uses internal 5.05 V reference and error amplifier for tight output tolerance. Use Value: Supports full-load operation across 7.5–40 V input range with thermal shutdown and UVLO - ensures reliability in unregulated industrial environments. |
| Negative Output Inverter (-12 V) | Multi-Output Off-Line Preconverter |
|
Use Scenario: Generating isolated -12 V/1.7 A for op-amp biasing and analog front-ends in test equipment. IC Role / Device Role / Timing Role: Configured in voltage-inverting topology; ground pin connected to negative output to reverse error amp polarity. Use Value: Achieves -12 V output with ±0.020% load regulation and 79.5% efficiency - eliminates need for dual-supply transformers or discrete inverters. |
Use Scenario: AC/DC preconversion stage feeding multiple downstream MC34167T-based post-regulators in distributed power systems. IC Role / Device Role / Timing Role: Post-regulator in off-line architecture; accepts 24 V DC from self-oscillating flyback preconverter (Fig. 28). Use Value: Enables independent, tightly regulated outputs (5 V, 12 V, -12 V) with <75 mVpp ripple - simplifies compliance with multi-rail system-level specs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar switching regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MC33167D2TG | Wider operating temperature range (−40 °C to +85 °C) vs. MC34167T (0 °C to +70 °C); identical electrical specs and pinout | Suitable for automotive under-hood or outdoor industrial deployments requiring extended ambient tolerance | Select MC33167D2TG when operating beyond 70 °C ambient or requiring AEC-Q100 alignment (though not officially qualified) |
| LM2576-5.0 | Lower switch current (3.0 A), fixed 5.0 V output (no adjustable FB), 52 kHz frequency, requires external diode and capacitor | Better suited for lower-power, cost-optimized 5 V supplies where 5 A capability is unnecessary | Choose LM2576-5.0 for simpler 3 A designs with minimal external components - avoid if >3 A or inverting topology needed |
Compared with MC33167D2TG, the MC34167T trades extended temperature range for lower cost and qualification maturity in commercial-grade systems; compared with LM2576-5.0, it offers higher current, adjustable output, and integrated switch - making it superior for scalable, multi-topology power design.
Availability
MC34167T is available at Aetrix Electronics and suitable for automotive auxiliary power supplies, industrial 5 V rail generation, and negative-output inverter circuits requiring stable component supply and long-term production continuity.
Supply support for MC34167T 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
onsemi (formerly ON Semiconductor) is a global semiconductor manufacturer specializing in energy-efficient power management, analog, and sensor solutions for automotive, industrial, and cloud infrastructure markets.
The MC34167T belongs to onsemi's legacy monolithic switching regulator product line, engineered for robust, low-component-count DC-DC conversion in cost-sensitive and thermally demanding applications.
FAQ
What is the maximum output current supported by the MC34167T?
The MC34167T integrates a power switch rated for 5.0 A continuous output current, with a typical current limit threshold of 6.5 A. Actual deliverable current depends on thermal management: with proper heatsinking (e.g., AAVID 5903B), it sustains 5.0 A in step-down configuration at 12 V input. Derating is required above 70 °C ambient due to its 0 °C to +70 °C operating range.
Can the MC34167T be used in a step-up (boost) configuration?
Yes, the MC34167T can be used in step-up applications, but not as a standalone boost controller. As documented in Figure 21, it requires an external power MOSFET (e.g., MTP3055EL) and gate protection network when input exceeds 20 V. The internal switch handles only the control side; energy transfer relies on the external FET and inductor - making it a step-up/down hybrid solution rather than pure boost.
What is the purpose of the 5.05 V reference in the MC34167T?
The 5.05 V reference in the MC34167T is a precision ±2% internal bandgap voltage used as the non-inverting input of the error amplifier. It is intentionally set 50 mV above 5.0 V to compensate for typical 1% voltage drop across PCB traces and connectors - ensuring the final load receives exactly 5.0 V when configured in standard step-down mode without external feedback resistors.
How does the standby mode function on the MC34167T?
Standby mode on the MC34167T activates when the voltage at Pin 1 (Compensation) is pulled below 150 mV, causing internal circuitry to reduce quiescent supply current to 36 µA at 12 V. This is implemented by clamping the error amplifier output, disabling PWM activity while retaining UVLO and thermal protection - ideal for battery-backed systems needing ultra-low idle power.
Is the MC34167T pin-compatible with the MC33167 series?
Yes, the MC34167T is pin-compatible and functionally identical to the MC33167 series in all electrical and pinout aspects. The sole difference is the operating temperature range: MC34167T is rated for 0 °C to +70 °C, while MC33167 variants extend to −40 °C to +85 °C. No PCB layout changes are needed when substituting within their respective temperature envelopes.
MC34167T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-220-5
- 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):
- 7.5V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 5.05V
- Voltage - Output (Max):
- 40V (Switch)
- Current - Output:
- 5.5A (Switch)
- Frequency - Switching:
- 72kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220-5
MC34167T FAQ
1.How can I place an order for MC34167T through Aetrix?
Please submit a Request for Quotation (RFQ) for MC34167T 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 MC34167T reliable?
The price and inventory of MC34167T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC34167T is usually 5 days.
3.What payment methods are accepted for MC34167T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC34167T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC34167T?
MC34167T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC34167T 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 MC34167T?
For technical support, including MC34167T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC34167T requirements.
6.How does Aetrix verify that MC34167T is sourced from the original manufacturer or authorized distributors?
All MC34167T 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 MC34167T meets industry standards.
7.What is the process for return or replacement of MC34167T?
All MC34167T units undergo pre-shipment inspection (PSI). If there is an issue with MC34167T, 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 MC34167T part is unused and in its original packaging.
Return procedure for MC34167T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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