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onsemi MC33166D2TR4G
- Part No.:
- MC33166D2TR4G
- Manufacturer:
- onsemi
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
MC33166D2TR4G.pdf
- Description:
- IC REG BUCK BST ADJ 3.3A D2PAK-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,556
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Product details
Overview
MC33166D2TR4G 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 3.0 A output switch, 72 kHz oscillator, 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 delivers regulated outputs in automotive, industrial, and embedded power supplies.
For engineers reviewing the MC33166D2TR4G datasheet, pinout, applications, or equivalent options, this device supports high-efficiency, low-component-count designs requiring stable 5 V, inverted, or boosted outputs with built-in protection and standby mode (36 µA supply current).
Technical Context
The MC33166D2TR4G implements voltage-mode PWM control using an internal error amplifier with 80 dB open-loop gain and 600 kHz unity-gain bandwidth, referenced to a trimmed 5.05 V bandgap. Its oscillator generates a fixed 72 kHz ramp with 95% max duty cycle, synchronized to a latch that prevents multiple pulses per cycle.
Current sensing is achieved via an internal resistor converting switch collector current to voltage, compared against a threshold (typ. 4.3 A) to trigger cycle-by-cycle limiting. Undervoltage lockout activates at 5.9 V (±0.3 V hysteresis), and thermal shutdown engages at ~170°C - both disabling the output latch without external components.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Oscillator Frequency | 72 kHz nominal; enables predictable EMI filtering and consistent loop response in all topologies. |
| Output Switch Current | 3.0 A continuous; supports ≥2.0 A load in step-down configurations with proper heatsinking (D2PAK θJC = 5.0°C/W). |
| Reference Voltage | 5.05 V ±2% at +25°C; sets base output without external divider; compensates for typical 1% cable drop to deliver true 5.0 V at load. |
| Input Voltage Range | 7.5 V to 40 V; compatible with 12 V/24 V automotive and industrial rails, including pre-regulated off-line supplies. |
| Standby Supply Current | 36 µA at 12 V; achieved by clamping Pin 5 < 150 mV; reduces system quiescent power during sleep or fault holdoff. |
| Operating Temperature | −40°C to +85°C; qualified for extended industrial and automotive under-hood environments. |
| Package | D2PAK (Case 936A); surface-mount, thermally enhanced; heatsink tab connected to Pin 3 (GND). |
Pinout & Package
D2PAK (Case 936A) package with exposed metal tab thermally and electrically connected to Pin 3 (GND). Mounting requires soldered thermal pad for optimal junction-to-board heat transfer (θJA = 70°C/W on 2 oz. copper, 30 mm length).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (Comp) | Compensation node | Connects to error amplifier output; external RC network (RF/CF) sets loop stability for all topologies. |
| Pin 2 (FB) | Voltage feedback input | Senses output via resistor divider; threshold = 5.05 V; regulates output by adjusting duty cycle. |
| Pin 3 (GND) | Power and signal ground | Common return for internal circuits; tab connection provides low-inductance thermal path to PCB. |
| Pin 4 (VCC) | Power supply input | Accepts 7.5–40 V; powers internal circuitry; UVLO monitors this pin to enable/disable operation. |
| Pin 5 (SW) | Switch collector output | Drives external inductor; rated for −1.5 V to +VIN; requires Schottky rectifier (e.g., 1N5822) in flyback paths. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 72 kHz oscillator with on-chip timing | Eliminates external timing capacitor; ensures consistent frequency across temperature (±10% over −40°C to +85°C). |
| 0% to 95% programmable duty cycle | Enables full-range output regulation from near-zero to near-input voltage in step-down, and deep inversion in inverting mode. |
| Cycle-by-cycle current limiting | Protects switch and inductor during startup, short-circuit, or overload without latch-up; threshold typ. 4.3 A. |
| Undervoltage lockout with hysteresis | Prevents erratic operation during brown-out; starts at 5.9 V, releases at 5.0 V (0.9 V hysteresis). |
| Internal thermal shutdown | Forces latch reset above ~170°C junction; protects die during sustained overload or inadequate heatsinking. |
Applications
| Automotive Body Control Module | Industrial PLC I/O Power |
|---|---|
|
Use Scenario: Regulating 5 V rail from 12 V battery for microcontroller, CAN transceiver, and sensor interfaces in door modules. IC Role / Device Role / Timing Role: Primary step-down controller; manages transient load steps up to 2 A while maintaining <±0.05% line regulation. Use Value: Single-chip solution eliminates external oscillator and reduces BOM count vs. controller+MOSFET alternatives. |
Use Scenario: Generating isolated −12 V bias for analog input op-amps and ADC drivers in modular I/O cards. IC Role / Device Role / Timing Role: Inverting regulator core; uses shared inductor and Schottky diode to deliver 1.0 A at −12 V with 81.2% efficiency. Use Value: Internal 5.05 V reference and error amp eliminate need for external precision reference, reducing layout sensitivity. |
| Off-Line AC/DC Preconverter | Brushed DC Motor Speed Control |
|
Use Scenario: 24 V intermediate bus generation from rectified AC line using self-oscillating flyback stage feeding MC33166D2TR4G post-regulator. IC Role / Device Role / Timing Role: Post-regulation switcher; maintains tight 5 V output despite input ripple from 50 kHz preconverter. Use Value: 72 kHz fixed frequency simplifies EMI filter design upstream of sensitive digital loads. |
Use Scenario: Closed-loop speed control of 18 V brushed motor using back-EMF sensing and variable duty-cycle drive. IC Role / Device Role / Timing Role: PWM generator and power switch; adjusts conduction time based on EMF feedback to maintain RPM setpoint. Use Value: Integrated current limit and thermal shutdown prevent MOSFET failure during stall or jam conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar switching regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MC34166D2TR4G | Same silicon, wider temp range (0°C to +70°C); lower max operating ambient than MC33166. | Not suitable for −40°C cold-start automotive use; preferred where cost-sensitive commercial-grade operation suffices. | Select when ambient stays >0°C and Pb-free D2PAK tape-and-reel is required. |
| LM2576HVSX-5.0/NOPB | 5 V fixed-output buck regulator; 3 A switch; 52 kHz freq; no inverting capability; integrated feedback divider. | Limited to step-down only; lacks voltage-inverting or step-up/down flexibility; simpler layout but less topology versatility. | Choose for dedicated 5 V step-down where simplicity and footprint matter more than multi-topology support. |
Compared with MC34166D2TR4G and LM2576HVSX-5.0/NOPB, the MC33166D2TR4G uniquely supports inverting and step-up/down configurations without external gate drivers, enabling compact dual-rail or battery-boosted designs where topology flexibility outweighs fixed-output convenience.
Availability
MC33166D2TR4G is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC power supplies, off-line preconverters, and brushed motor controllers requiring stable component supply across extended temperature ranges.
Supply support for MC33166D2TR4G 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 supplier focused on energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and IoT markets.
The MC33166 series was engineered for robust, low-BOM-count DC-DC conversion in harsh environments - emphasizing integrated protection, wide input range, and topology flexibility for cost-sensitive industrial and automotive subsystems.
FAQ
What is the maximum output current achievable with MC33166D2TR4G in step-down configuration?
The MC33166D2TR4G supports up to 3.0 A continuous switch current. In practical step-down designs with adequate D2PAK heatsinking (e.g., AAVID 5903B), it reliably delivers 2.0–2.5 A at 5 V with >82% efficiency. Peak current capability is limited by cycle-by-cycle limiting (min. 3.3 A threshold) and thermal dissipation - derate above +60°C ambient.
Can MC33166D2TR4G be used in voltage-inverting applications, and what is required?
Yes, MC33166D2TR4G is explicitly designed for voltage-inverting topologies. Per Figure 23 in the datasheet, the IC ground (Pin 3) must connect to the negative output rail - reversing error amplifier polarity and keeping the switch emitter within −1.5 V rating. A Schottky diode (e.g., 1N5822) and properly wound inductor are mandatory for stable −12 V/1.0 A operation.
Does MC33166D2TR4G require an external timing capacitor?
No. The MC33166D2TR4G integrates a trimmed current source and capacitor for its 72 kHz oscillator - eliminating the need for external timing components. This simplifies layout, improves frequency stability over temperature, and reduces bill-of-materials versus adjustable-frequency controllers.
What is the purpose of Pin 5 (SW) voltage range specification (−1.5 V to +VIN)?
The −1.5 V minimum on Pin 5 (SW) defines the maximum allowable negative swing during inverting operation. Exceeding this risks damaging the internal switch. In inverting designs, grounding the IC's Pin 3 to the negative output rail ensures the emitter stays within safe limits while enabling correct feedback polarity - a critical constraint confirmed in the "Voltage-Inverting Converter" section (p.11).
How does the standby mode function in MC33166D2TR4G, and how is it activated?
Standby mode reduces MC33166D2TR4G supply current to 36 µA by pulling Pin 1 (Comp) below 150 mV - disabling the oscillator and PWM latch. This is typically implemented with a transistor or logic signal sinking Pin 1. The feature enables ultra-low-power hold states in battery-backed systems without removing input voltage.
MC33166D2TR4G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Last Time Buy
- 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:
- 3.3A (Switch)
- Frequency - Switching:
- 72kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- D2PAK-5
MC33166D2TR4G FAQ
1.How can I place an order for MC33166D2TR4G through Aetrix?
Please submit a Request for Quotation (RFQ) for MC33166D2TR4G 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 MC33166D2TR4G reliable?
The price and inventory of MC33166D2TR4G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC33166D2TR4G is usually 5 days.
3.What payment methods are accepted for MC33166D2TR4G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC33166D2TR4G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC33166D2TR4G?
MC33166D2TR4G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC33166D2TR4G 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 MC33166D2TR4G?
For technical support, including MC33166D2TR4G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC33166D2TR4G requirements.
6.How does Aetrix verify that MC33166D2TR4G is sourced from the original manufacturer or authorized distributors?
All MC33166D2TR4G 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 MC33166D2TR4G meets industry standards.
7.What is the process for return or replacement of MC33166D2TR4G?
All MC33166D2TR4G units undergo pre-shipment inspection (PSI). If there is an issue with MC33166D2TR4G, 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 MC33166D2TR4G part is unused and in its original packaging.
Return procedure for MC33166D2TR4G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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