My Inquiry
My Account
onsemi MC33166TV
- Part No.:
- MC33166TV
- Manufacturer:
- onsemi
- Package:
- TO-220-5 Formed Leads
- Datasheet:
-
MC33166TV.pdf
- Description:
- IC REG BUCK BST ADJ 3.3A TO220-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,505
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MC33166TV from onsemi is a fixed-frequency, voltage-mode switching regulator IC designed for step-down, voltage-inverting, and step-up/down DC-DC converter topologies. It integrates a 72 kHz oscillator, high-gain error amplifier with 5.05 V ±2% reference, latching PWM controller, and 3.0 A output switch - enabling compact, low-component-count power supplies operating from 7.5 V to 40 V input in industrial and automotive environments.
For engineers reviewing the MC33166TV datasheet, pinout, applications, or equivalent options, key selection criteria include its −40°C to +85°C operating range, cycle-by-cycle current limiting (4.3 A typ), undervoltage lockout (5.9 V startup), thermal shutdown, and standby mode reducing supply current to 36 µA - all critical for reliable offline and battery-fed power conversion designs.
Technical Context
The MC33166TV implements voltage-mode control using an internal 5.05 V reference and error amplifier with 80 dB open-loop gain and 600 kHz unity-gain bandwidth. Its oscillator delivers a fixed 72 kHz frequency (62–79 kHz over temperature) with 95% max duty cycle, while the PWM latch prevents multiple pulses per cycle via ramp-compare architecture.
Protection is implemented through three independent circuits: cycle-by-cycle current sensing (threshold 3.3–6.0 A), undervoltage lockout with 0.9 V hysteresis (startup at 5.9 V), and thermal shutdown activating at ~170°C. The device supports soft-start via external capacitor on Pin 5 and enters low-power standby when Pin 5 is clamped below 150 mV.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Oscillator Frequency | 72 kHz nominal (62–79 kHz over temp); sets minimum inductor size and EMI profile for stable loop design |
| Reference Voltage | 5.05 V ±2% at 25°C; enables precise 5.0 V output without external divider, compensating for typical 1% cable drop |
| Output Switch Current | 3.0 A continuous (4.3 A current limit threshold); supports up to 3 A load in step-down configuration with proper heatsinking |
| Input Voltage Range | 7.5 V to 40 V; accommodates 12 V/24 V automotive batteries and industrial rails with margin |
| Operating Temperature | −40°C to +85°C; qualified for under-hood automotive and wide-temperature industrial use |
| Standby Supply Current | 36 µA at 12 V; enables ultra-low quiescent power during system sleep modes |
| UVLO Threshold | 5.9 V startup with 0.9 V hysteresis; prevents erratic operation during brown-out or cold-cranking conditions |
Pinout & Package
MC33166TV is housed in a 5-lead TO-220 package (Case 314B), with the metal tab thermally and electrically connected to Pin 3 (Ground). The vertical-mount leadform supports direct heatsink attachment for thermal management in high-current applications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Compensation | Output of error amplifier; connects to RC network for loop stability tuning and soft-start capacitor |
| Pin 2 | Switch Output | Collector of internal NPN power transistor; drives external inductor in step-down or inverter topologies |
| Pin 3 | Ground | Power and signal ground reference; tied to heatsink tab for thermal conduction and noise control |
| Pin 4 | VCC | Main power supply input (7.5–40 V); powers internal circuitry and provides bias for oscillator and reference |
| Pin 5 | Feedback | Inverting input of error amplifier; senses regulated output via resistor divider to maintain 5.05 V reference |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 72 kHz oscillator with on-chip timing | Eliminates external timing components; ensures consistent switching frequency across temperature and line variations |
| 5.05 V ±2% precision reference | Enables accurate 5.0 V output regulation without trimming; reduces BOM count and improves long-term stability |
| 0% to 95% output duty cycle range | Supports wide input-to-output voltage ratios in step-down and inverting configurations without duty-cycle saturation |
| Cycle-by-cycle current limiting | Protects switch and magnetics during overload or short-circuit; resets each cycle to prevent thermal runaway |
| Undervoltage lockout with hysteresis | Ensures clean start-up and shutdown; prevents oscillation near brown-out thresholds in automotive systems |
Applications
| Automotive Body Control Module (BCM) | Industrial Programmable Logic Controller (PLC) I/O Power |
|---|---|
Use Scenario: Regulating 5 V rail from 12 V battery in BCM for microcontroller, CAN transceiver, and sensor interfaces under cold-crank (6.5 V) and load-dump (36 V) conditions. IC Role / Device Role / Timing Role: Primary step-down controller managing inductor current, feedback loop, and protection functions - replacing discrete transistor-based regulators. Use Value: Single-chip solution reduces board area by >40% vs. discrete alternatives while maintaining 82.8% efficiency at 3 A and surviving −40°C to +85°C ambient. | Use Scenario: Generating isolated ±12 V and +5 V outputs from 24 V DC bus in PLC backplane to power analog I/O, digital logic, and RS-485 transceivers. IC Role / Device Role / Timing Role: Core voltage-inverting and step-down controller in multi-output flyback-derived topology, coordinating energy transfer via transformer secondaries. Use Value: Enables triple-output regulation (5 V/2 A, +12 V/300 mA, −12 V/100 mA) with <±0.05% line regulation and 83.3% total efficiency using one MC33166TV per channel. |
| Off-line AC-DC Preconverter | Brushed DC Motor Speed Control |
Use Scenario: 24 V pre-regulated bus generation from rectified AC line (via self-oscillating flyback) feeding downstream MC33166TV-based post-regulators in distributed power systems. IC Role / Device Role / Timing Role: Post-regulator IC implementing tight-voltage-step-down with fast transient response and EMI-controlled 72 kHz switching. Use Value: Achieves 90% overall preconverter efficiency and <50 mVpp ripple on 5 V output while supporting 125 W total system power with traceable thermal performance. | Use Scenario: Closed-loop speed control of 18 V brushed motor using back-EMF sensing, requiring stable 5 V supply for comparator and gate driver circuitry. IC Role / Device Role / Timing Role: Dedicated 5 V power supply IC ensuring clean, regulated voltage for analog sensing and PWM control logic despite motor-induced supply noise. Use Value: Delivers 3 A peak current with <1% speed regulation over 12–24 V input range, leveraging UVLO hysteresis and thermal shutdown to survive motor stall 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 core architecture but rated for 0°C to +70°C; D2PAK surface-mount package; Pb-free tape-and-reel | Preferred for commercial-grade, space-constrained PCBs where thermal mass is managed externally | Select when ambient temperature stays within 0–70°C and SMT assembly is required |
| LM2596T-5.0 | 3 A buck regulator with 150 kHz switching, integrated diode, and different compensation scheme; no inverting capability | Limited to step-down only; lacks voltage-inverting and step-up/down flexibility of MC33166TV | Choose for simpler 5 V step-down needs where footprint and ease-of-use outweigh topology versatility |
Compared with MC34166D2TR4G, the MC33166TV offers extended temperature range and through-hole mounting for ruggedized designs; versus LM2596T-5.0, it provides broader topology support (inverting, step-up/down) and higher design flexibility at the cost of external diode requirement and more complex loop compensation.
Availability
MC33166TV is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC power supplies, off-line preconverters, and brushed motor control systems requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MC33166TV 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 delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The MC33166TV belongs to onsemi's legacy high-voltage switching regulator product line, engineered for robust, low-cost DC-DC conversion in harsh environments - emphasizing thermal resilience, wide-input operation, and topology flexibility over integration density.
FAQ
What is the maximum output current capability of the MC33166TV?
The MC33166TV supports up to 3.0 A continuous output current in step-down configuration when properly heatsinked. Its internal switch has a guaranteed current limit threshold of 3.3 A (min), rising to 6.0 A (max) over temperature. Actual deliverable current depends on layout, heatsinking, input voltage, and ambient temperature - with 3 A achievable at 12 V input and 25°C ambient using AAVID 5903B heatsink per datasheet Figure 20.
Does the MC33166TV support voltage-inverting topologies?
Yes, the MC33166TV is explicitly designed for voltage-inverting applications, as confirmed in the datasheet introduction and Figure 23. It achieves negative output by reconfiguring ground reference and using the internal switch in emitter-follower mode. The device maintains 81.2% efficiency at −12 V/1.0 A and supports line/load regulation better than ±0.017% in this configuration.
What is the purpose of Pin 5 (Feedback) on the MC33166TV?
Pin 5 is the inverting input of the internal error amplifier and serves as the feedback node for output voltage regulation. It compares the scaled output voltage (via external resistor divider) against the 5.05 V internal reference. When the sensed voltage deviates, the amplifier adjusts the PWM duty cycle to correct the output - enabling precise regulation without external op-amps or references.
Can the MC33166TV be used in step-up (boost) configurations?
Yes, the MC33166TV can be used in step-up applications, though not as a standalone boost controller. Per datasheet Figure 21, it requires an external MOSFET (e.g., MTP3055EL) and gate protection network when input exceeds 20 V. This step-up/down configuration provides inherent short-circuit protection and programmable output voltages both above and below input voltage.
Is the MC33166TV still recommended for new designs?
No - the MC33166TV is marked DISCONTINUED in the official onsemi datasheet (page 2, Note 3). While available through Aetrix Electronics for legacy support and repair, onsemi recommends evaluating modern alternatives such as the NCP302 or LV5400 series for new designs due to improved efficiency, smaller footprints, and active technical support.
MC33166TV Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-220-5 Formed Leads
- 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:
- 3.3A (Switch)
- Frequency - Switching:
- 72kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220-5
MC33166TV FAQ
1.How can I place an order for MC33166TV through Aetrix?
Please submit a Request for Quotation (RFQ) for MC33166TV 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 MC33166TV reliable?
The price and inventory of MC33166TV are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC33166TV is usually 5 days.
3.What payment methods are accepted for MC33166TV?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC33166TV transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC33166TV?
MC33166TV orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC33166TV 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 MC33166TV?
For technical support, including MC33166TV datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC33166TV requirements.
6.How does Aetrix verify that MC33166TV is sourced from the original manufacturer or authorized distributors?
All MC33166TV 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 MC33166TV meets industry standards.
7.What is the process for return or replacement of MC33166TV?
All MC33166TV units undergo pre-shipment inspection (PSI). If there is an issue with MC33166TV, 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 MC33166TV part is unused and in its original packaging.
Return procedure for MC33166TV:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MC33166TV Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
