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Microchip Technology MIC3231YML-TR
- Part No.:
- MIC3231YML-TR
- Manufacturer:
- Microchip Technology
- Category:
- LED Drivers
- Package:
- 12-VFDFN Exposed Pad, 12-MLF®
- Datasheet:
-
MIC3231YML-TR.pdf
- Description:
- IC LED DRIVER CTRLR PWM 12MLF
- Quantity:
- Payment:
- Shipping:
Inventory:3,663
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Product details
Overview
MIC3231YML-TR from Micrel is a constant-current boost switching controller for high-power LED strings, operating from 6V to 45V input and delivering up to 70W via external MOSFET. It features programmable 100kHz–1MHz switching frequency, ±3% 250mV feedback reference, PWM dimming support up to 500Hz, and integrated OVP, UVLO, and thermal shutdown. Used in street lighting and architectural LED systems.
For engineers reviewing the MIC3231YML-TR datasheet, MIC3231YML-TR pinout, MIC3231YML-TR application, or MIC3231YML-TR equivalent, key selection criteria include dither-enabled EMI reduction, external current-sense resistor programming, 12-pin 3mm × 3mm MLF® package compatibility, and synchronization capability with other MIC3230 devices.
Technical Context
The MIC3231YML-TR implements peak current mode control with slope compensation set by an external resistor (RSLC), enabling stable operation across wide duty cycles. Its internal gate driver delivers 2Ω source / 3.5Ω sink impedance to drive large external FETs efficiently.
It uses a 250mV feedback reference at IADJ for precise LED current regulation, with current sense (IS) monitoring both inductor current and overcurrent protection at 0.45V threshold. Dithering shifts switching frequency by ±12% to reduce conducted EMI by ~10dB - a feature exclusive to MIC3231 within the family.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 6V to 45V - supports wide-range DC inputs including 12V/24V/36V industrial and automotive supplies. |
| Feedback Reference | 250mV ±3% - enables accurate LED current setting via RADJ resistor with minimal drift over temperature. |
| Switching Frequency | 100kHz to 1MHz (programmable via RFS) - allows trade-off between efficiency (lower fSW) and component size (higher fSW). |
| Dither Range | ±12% frequency shift - spreads EMI spectrum to reduce peak emissions by ~10dB in sensitive applications. |
| OVP Threshold | 1.24V typical - protects LED string and external components from overvoltage during open-load or transient conditions. |
| Junction Temp Range | –40°C to +125°C - ensures reliable operation in outdoor lighting and high-ambient industrial environments. |
| Thermal Shutdown | 150°C with 5°C hysteresis - prevents damage during sustained overload or poor heatsinking. |
Pinout & Package
Package: 12-pin 3mm × 3mm MLF® with exposed EPAD connected to AGND for thermal and electrical performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Power Input | Accepts 6–45V supply; decoupled with ≥4.7µF ceramic capacitor near pin. |
| EN | Enable Control | Logic-high (>1.5V) enables operation; logic-low (<0.4V) shuts down IC with 30µA quiescent current. |
| PWMD | PWM Dimming Input | Accepts 0–500Hz PWM signal; controls LED brightness without color shift. |
| COMP | Compensation Node | Connects external RC network (e.g., 10nF + 10kΩ) to stabilize current loop. |
| IADJ | Current Sense Feedback | Monitors voltage across RADJ; regulates LED current to maintain 250mV at this pin. |
| FS | Frequency Select | Resistor-to-GND sets oscillator frequency (100kHz–1MHz); e.g., 16.5kΩ = 500kHz. |
| IS | Current Sense Input | Inputs voltage from external RCS resistor; triggers current limit at 0.45V and provides slope compensation ramp. |
| OVP | Over-Voltage Protection | Connects top of resistive divider to output; trips at 1.24V to clamp VOUT during fault. |
| PGND | Power Ground | High-current return path for gate driver and IS sensing; separate from AGND for noise isolation. |
| DRV | Gate Driver Output | Drives external N-channel MOSFET gate; 2Ω source / 3.5Ω sink impedance minimizes switching losses. |
| VDD | Internal Bias Rail | Internally regulated; requires 10µF ceramic bypass to PGND - no external load permitted. |
| EPAD | Thermal Pad | Must be soldered to PCB copper pour tied to AGND for thermal dissipation (θJA = 60.7°C/W). |
Key Features
| Feature | Design Value |
|---|---|
| Dither-enabled EMI reduction | ±12% frequency modulation lowers peak conducted emissions by ~10dB - critical for FCC/CE compliance in lighting fixtures. |
| Programmable LED current | Set precisely via RADJ resistor (e.g., 0.71Ω for 350mA); eliminates need for trimming or calibration. |
| External MOSFET drive | Low-impedance DRV pin supports high-current discrete FETs - enables scalable power delivery up to 70W per channel. |
| Multi-device synchronization | SYNC pin (not present on MIC3231YML-TR) is omitted; only MIC3230 supports sync - MIC3231 operates standalone or asynchronously. |
| Comprehensive protection | OVP, UVLO (4.9V turn-on), thermal shutdown (150°C), and cycle-by-cycle current limiting prevent system-level failures. |
Applications
| Street Lighting | Architectural Lighting |
|---|---|
Use Scenario: Outdoor LED luminaires powered from 24V or 36V DC distribution lines in municipal infrastructure. IC Role / Device Role / Timing Role: Constant-current boost controller regulating 350mA–700mA through 5–12 series-connected white LEDs. Use Value: Maintains consistent lumen output despite input voltage sag or temperature drift, extending LED lifetime beyond 50,000 hours. | Use Scenario: Color-tuned façade lighting with multiple independent LED channels requiring low-EMI operation near sensitive receivers. IC Role / Device Role / Timing Role: Primary current regulator with dither-enabled switching to suppress narrowband EMI peaks in dense installation environments. Use Value: Enables Class B EMC compliance without added filtering, reducing BOM cost and board area in compact driver modules. |
| Solid State Lighting | Industrial High-Bay Fixtures |
Use Scenario: Commercial retrofit lamps replacing HID fixtures, operating from universal 12–45V DC input rails. IC Role / Device Role / Timing Role: Programmable-frequency boost controller supporting flexible inductor selection to optimize efficiency vs. size. Use Value: Achieves >80% efficiency across 10:1 input range while maintaining ±3% current accuracy - critical for energy certification (DLC, ENERGY STAR). | Use Scenario: Factory-floor high-bay luminaires exposed to ambient temperatures up to +75°C and vibration. IC Role / Device Role / Timing Role: Robust current controller with –40°C to +125°C junction rating and thermal shutdown hysteresis. Use Value: Prevents thermal runaway under sustained overload or heatsink degradation, ensuring safety-critical reliability in unattended operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar constant-current LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MIC3230YML-TR | No dither; includes SYNC pin for multi-controller synchronization; identical pinout and biasing. | Better suited for multi-channel synchronized drivers where EMI is managed system-wide rather than per-channel. | Select MIC3230YML-TR when coordinating >1 boost stage or when dither is unnecessary. |
| LM3410XMY/NOPB | Fixed 1.6MHz fSW; no dither; lower max input (24V); integrated 1.5A FET; smaller 6-pin SOT-23 package. | Limited to ≤5W LED loads; unsuitable for 70W street lighting but ideal for indicator or signage applications. | Choose LM3410XMY/NOPB for space-constrained, low-power designs where integration outweighs flexibility. |
Compared with MIC3230YML-TR, MIC3231YML-TR trades synchronization capability for superior EMI performance via dither; versus LM3410XMY/NOPB, it offers higher power scalability, wider input range, and external FET control - making it the only option rated for 70W solid-state lighting systems.
Availability
MIC3231YML-TR is available at Aetrix Electronics and suitable for street lighting, architectural LED systems, and industrial high-bay fixtures requiring stable component supply across extended production lifecycles.
Supply support for MIC3231YML-TR 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
Micrel Inc. was a U.S.-based analog and mixed-signal semiconductor company acquired by Microchip Technology in 2015; known for high-reliability power management and LED driver ICs.
The MIC323x product line was designed specifically for constant-current, high-efficiency boost-mode LED drivers in demanding outdoor and industrial lighting applications - emphasizing thermal robustness, EMI control, and design flexibility.
FAQ
What is the function of the FS pin on the MIC3231YML-TR?
The FS (Frequency Select) pin on the MIC3231YML-TR accepts a resistor to ground that sets the oscillator frequency between 100kHz and 1MHz. For example, a 16.5kΩ resistor yields ~500kHz operation. This allows designers to balance efficiency (lower fSW) against magnetic component size (higher fSW), directly impacting thermal design and bill-of-materials cost in the final MIC3231YML-TR implementation.
Does the MIC3231YML-TR support PWM dimming, and what is its maximum frequency?
Yes, the MIC3231YML-TR supports PWM dimming via the PWMD pin with guaranteed operation up to 500Hz. The IC maintains constant LED current during each PWM pulse, preventing color shift common with analog dimming. For flicker-free operation, use frequencies above 120Hz - a requirement met by the full 0–500Hz range supported by the MIC3231YML-TR.
How does the dither feature in the MIC3231YML-TR reduce EMI?
The MIC3231YML-TR's dither feature modulates the switching frequency by ±12% around its nominal value, spreading conducted EMI energy across a wider spectrum. This reduces peak emissions by approximately 10dB - a measurable improvement verified in EMC testing - making the MIC3231YML-TR especially valuable in lighting products targeting Class B FCC/CE compliance without added filter components.
What package type and thermal characteristics apply to the MIC3231YML-TR?
The MIC3231YML-TR uses a 12-pin 3mm × 3mm MLF® package with an exposed EPAD thermally connected to AGND. Its junction-to-ambient thermal resistance is 60.7°C/W, enabling reliable operation at full load in ambient temperatures up to +75°C when mounted on ≥2in² of 2-oz copper. The EPAD must be soldered to ensure thermal performance specified in the MIC3231YML-TR datasheet.
Can the MIC3231YML-TR be used in SEPIC topology, or is it boost-only?
The MIC3231YML-TR is explicitly designed for boost topology but can also be configured as a SEPIC controller per Micrel's functional description - allowing output voltage to be either above or below input voltage. This requires modified external component layout (e.g., coupled inductor, additional capacitor) and careful compensation tuning. While feasible, the MIC3231YML-TR reference designs and characterization data focus on boost operation; SEPIC use requires full validation per application requirements.
MIC3231YML-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 12-VFDFN Exposed Pad, 12-MLF®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- DC DC Controller
- Topology:
- Step-Up (Boost)
- Internal Switch(s):
- No
- Number of Outputs:
- 1
- Voltage - Supply (Min):
- 6V
- Voltage - Supply (Max):
- 45V
- Voltage - Output:
- -
- Current - Output / Channel:
- -
- Frequency:
- 100kHz ~ 1MHz
- Dimming:
- PWM
- Applications:
- Lighting
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 12-MLF™ (4x4)
MIC3231YML-TR FAQ
1.How can I place an order for MIC3231YML-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC3231YML-TR 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 MIC3231YML-TR reliable?
The price and inventory of MIC3231YML-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC3231YML-TR is usually 5 days.
3.What payment methods are accepted for MIC3231YML-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC3231YML-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC3231YML-TR?
MIC3231YML-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC3231YML-TR 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 MIC3231YML-TR?
For technical support, including MIC3231YML-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC3231YML-TR requirements.
6.How does Aetrix verify that MIC3231YML-TR is sourced from the original manufacturer or authorized distributors?
All MIC3231YML-TR 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 MIC3231YML-TR meets industry standards.
7.What is the process for return or replacement of MIC3231YML-TR?
All MIC3231YML-TR units undergo pre-shipment inspection (PSI). If there is an issue with MIC3231YML-TR, 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 MIC3231YML-TR part is unused and in its original packaging.
Return procedure for MIC3231YML-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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