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Microchip Technology MIC2171WU
- Part No.:
- MIC2171WU
- Manufacturer:
- Microchip Technology
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
MIC2171WU.pdf
- Description:
- IC REG BUCK BST ADJ 2.5A TO263-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,046
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Product details
Overview
MIC2171WU from Microchip Technology is a 100 kHz current-mode PWM controller IC with integrated 65V/2.5A NPN power switch, designed for step-up, step-down, inverting, Cuk, and isolated flyback/forward topologies. It operates from 3V to 40V input, delivers up to 50W (with external switch), features internal cycle-by-cycle current limiting, and draws only 7 mA quiescent current - making it ideal for battery-powered handheld instruments and laptop DC-DC conversion.
For engineers reviewing the MIC2171WU datasheet, MIC2171WU pinout, MIC2171WU application, or MIC2171WU equivalent, key selection considerations include its 2.5A peak switch rating, 1.24V feedback reference, TO-263-5 package thermal performance (θJA = 45°C/W), and compatibility with LT1171/LM2577 socket footprints in portable power designs.
Technical Context
The MIC2171WU implements fixed-frequency (88–112 kHz) current-mode control using an internal transconductance error amplifier (gm = 3.0–6.0 µA/mV) and 1.24V precision bandgap reference. Its floating switch architecture enables topology flexibility without requiring external high-side drivers.
It integrates anti-saturation circuitry to extend usable duty cycle up to 95%, employs internal cycle-by-cycle current limiting (2.5–5.5 A depending on duty cycle and temperature), and supports soft-start and current-limit tailoring via the COMP pin - all while maintaining stable operation across –40°C to +85°C ambient.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switch Rating | 65V VBR, 2.5A peak - supports 50W off-line boost with external switch or 12–15W self-contained designs |
| Input Voltage Range | 3.0V to 40V - enables direct operation from single Li-ion to 24V industrial rails |
| Feedback Reference | 1.240V ±24mV - sets output voltage via resistor divider; line regulation ≤0.6%/V ensures stability over wide VIN |
| Quiescent Current | 7 mA typical - minimizes standby loss in battery-operated equipment |
| Oscillator Frequency | 100 kHz nominal (88–112 kHz) - balances EMI, efficiency, and magnetics size for portable applications |
| Max Duty Cycle | 90% - allows high step-up ratios (e.g., 5V→12V) without external duty cycle clamping |
| Thermal Resistance | θJA = 45°C/W (TO-263-5) - requires ≥2 in² copper pour for reliable 1.3W dissipation at 70°C ambient |
Pinout & Package
Package: 5-pin TO-263 (SMD), tab-connected to GND, rated for –40°C to +85°C ambient operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - COMP | Error amplifier output | Transconductance-type node for loop compensation, soft-start capacitor connection, or current limit clamping |
| 2 - FB | Inverting input of error amplifier | Connects to resistor divider midpoint; senses output voltage with 310–1100 nA bias current |
| 3 - GND | Power and signal ground | Must tie directly to input capacitor ground; serves as return for internal regulator and switch emitter |
| 4 - SW | Internal NPN collector | High-current switching node; connects to inductor (boost), transformer primary (flyback), or diode (buck) |
| 5 - IN | Supply input | Accepts 3–40V; powers internal 2.3V bias rail and driver; supplies current increases by 9–20 mA during switch conduction |
Key Features
| Feature | Design Value |
|---|---|
| Current-mode control | Eliminates right-half-plane zero in boost/flyback, simplifying compensation and enabling inherent input-voltage feed-forward |
| Internal 2.5A/65V switch | Reduces BOM count vs. controller-only ICs; eliminates gate-drive design complexity for ≤15W applications |
| Anti-saturation circuit | Extends effective duty cycle to 90%+ by removing stored base charge, critical for high-ratio step-up converters |
| COMP pin versatility | Supports soft-start (capacitor to GND), current foldback (voltage clamp), and conventional Type-II/III compensation networks |
| LT1171/LM2577 socket compatibility | Enables drop-in replacement in legacy TO-220/TO-263 layouts without PCB redesign |
Applications
| Laptop/Palmtop Power Supply | Battery-Operated Handheld Instrument |
|---|---|
Use Scenario: Generating 12V from a 5V logic rail to power analog front-end circuitry and display backlight. IC Role / Device Role / Timing Role: Step-up DC-DC controller with integrated switch; regulates output using 100 kHz PWM and 1.24V feedback reference. Use Value: Delivers 0.25A at 12V with <7 mA quiescent draw, extending runtime on single-cell Li-ion batteries. | Use Scenario: Converting 3.3V or 5V battery supply to 5V/0.5A isolated output for sensor excitation and data acquisition. IC Role / Device Role / Timing Role: Flyback controller with discontinuous conduction mode operation; uses transformer isolation and internal 2.5A switch. Use Value: Achieves galvanic isolation without external MOSFET or driver, reducing component count and board area in portable test gear. |
| Off-Line 50W Boost Converter | Predriver for High-Power SMPS |
Use Scenario: Stepping up 24V industrial bus to 48V for PoE++ or motor control interface. IC Role / Device Role / Timing Role: Primary controller in non-isolated boost stage; drives external N-channel MOSFET via SW pin. Use Value: Leverages internal current sensing and protection to manage up to 50W output while maintaining tight regulation under load transients. | Use Scenario: Driving external high-voltage/high-current switches (e.g., IGBTs or SiC MOSFETs) in industrial inverters or UPS systems. IC Role / Device Role / Timing Role: Current-mode predriver providing precise timing and cycle-by-cycle current limiting signals to gate drivers. Use Value: Enables robust overcurrent protection and fast transient response without adding complex current-sense amplifiers or digital controllers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar switching regulator controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2577T-12/NOPB | Fixed 12V output, no adjustable FB pin; 3A switch, 52 kHz oscillator; TO-220 only | Limited to fixed-output designs; lacks COMP pin flexibility for soft-start or current limiting | Select when fixed 12V output suffices and layout rework for frequency/compensation is not required |
| LT1171CT#PBF | 100 kHz, 4A switch, 60V rating; requires external compensation network; SO-8 and TO-220 packages | Higher current capability but no TO-263 option; less integrated anti-saturation circuitry | Prefer for higher-power boost where 4A switch headroom is needed and SMT footprint is acceptable |
Compared with LM2577T-12/NOPB, MIC2171WU offers adjustable output and superior thermal performance in TO-263; versus LT1171CT#PBF, it provides enhanced duty-cycle extension and tighter feedback tolerance, making it more suitable for precision battery-fed applications demanding low IQ and flexible topology support.
Availability
MIC2171WU is available at Aetrix Electronics and suitable for laptop power supplies, handheld instrumentation, and isolated flyback converters requiring stable component supply with long-term industrial availability.
Supply support for MIC2171WU 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
Microchip Technology Inc. is a leading provider of microcontrollers, analog devices, and power management ICs, serving automotive, industrial, and consumer markets with high-reliability silicon solutions.
The MIC2171 product line delivers integrated switching regulator controllers optimized for portable and battery-sensitive applications, emphasizing low quiescent current, topology flexibility, and ease of implementation across boost, buck, flyback, and forward configurations.
FAQ
What is the maximum output power achievable with MIC2171WU in a self-contained boost configuration?
The MIC2171WU supports up to ~15W in self-contained boost designs using its internal 2.5A/65V switch. This assumes 12V output from 5V input, 85% efficiency, and proper thermal management with ≥2 in² copper pour on the TO-263 tab. For >15W, the MIC2171WU can drive external switches in predriver mode - enabling up to 50W in off-line boost applications as documented in the datasheet.
Does MIC2171WU support adjustable output voltage, and how is it configured?
Yes, MIC2171WU supports fully adjustable output voltage via a resistor divider connected between VOUT, FB pin, and GND. The internal 1.24V reference determines regulation point using R1 and R2 per VOUT = 1.24 × (1 + R1/R2). Typical R1 values range from 3kΩ to 15kΩ to balance noise immunity and light-load efficiency - confirmed in Section 5.8 of the MIC2171WU datasheet.
Can MIC2171WU be used in flyback topology, and what are the critical design considerations?
Yes, MIC2171WU is explicitly validated for flyback operation in discontinuous conduction mode. Critical design considerations include selecting a transformer with ≤1.8:1 turns ratio (to keep switch voltage <65V), adding a voltage clipper (D1/R4/C3) if leakage inductance is high, and ensuring the COMP pin compensation network (R3/C2) stabilizes the loop - all detailed in Figures 5-2 and Equations 5-10 through 5-22 of the MIC2171WU datasheet.
What is the thermal performance difference between MIC2171WU (TO-263) and MIC2171WT (TO-220)?
Both MIC2171WU and MIC2171WT share identical θJA = 45°C/W when mounted per datasheet conditions: TO-263 requires ≥2 in² horizontal copper area, TO-220 requires vertical mounting with 4 in² surrounding copper. No thermal performance difference exists between packages under specified PCB layout rules - the choice depends on assembly process (SMT vs. through-hole) and board space constraints.
Is MIC2171WU pin-compatible with LT1171 or LM2577, and what does "socket compatible" mean?
MIC2171WU is socket-compatible with LT1171 and LM2577 in TO-220 and TO-263 packages - meaning identical pin numbering (IN, SW, GND, FB, COMP) and mechanical footprint allow direct replacement in existing layouts. However, electrical differences exist: MIC2171WU runs at 100 kHz (vs. 52 kHz for LM2577), has tighter feedback tolerance (±24 mV vs. ±50 mV), and includes enhanced anti-saturation circuitry - requiring minor compensation review but no PCB changes.
MIC2171WU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Up, Step-Down, Step-Up/Step-Down
- Output Configuration:
- Positive or Negative, Isolation Capable
- Topology:
- Buck, Boost, Cuk, Flyback, Forward Converter
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- -
- Voltage - Output (Max):
- 65V (Switch)
- Current - Output:
- 2.5A (Switch)
- Frequency - Switching:
- 100kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-263-5
MIC2171WU FAQ
1.How can I place an order for MIC2171WU through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC2171WU 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 MIC2171WU reliable?
The price and inventory of MIC2171WU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC2171WU is usually 5 days.
3.What payment methods are accepted for MIC2171WU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC2171WU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC2171WU?
MIC2171WU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC2171WU 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 MIC2171WU?
For technical support, including MIC2171WU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC2171WU requirements.
6.How does Aetrix verify that MIC2171WU is sourced from the original manufacturer or authorized distributors?
All MIC2171WU 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 MIC2171WU meets industry standards.
7.What is the process for return or replacement of MIC2171WU?
All MIC2171WU units undergo pre-shipment inspection (PSI). If there is an issue with MIC2171WU, 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 MIC2171WU part is unused and in its original packaging.
Return procedure for MIC2171WU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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