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Microchip Technology MIC2171BU TR
- Part No.:
- MIC2171BU TR
- Manufacturer:
- Microchip Technology
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
MIC2171BU TR.pdf
- Description:
- IC REG BUCK BST ADJ 2.5A TO263-5
- Quantity:
- Payment:
- Shipping:
Inventory:2,238
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Product details
Overview
MIC2171BU TR from Microchip Technology is a 100 kHz current-mode PWM controller IC with an 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 suitable for battery-powered handheld instruments and laptop auxiliary supplies.
For engineers reviewing the MIC2171BU TR datasheet, MIC2171BU TR pinout, MIC2171BU TR application, or MIC2171BU TR equivalent, key selection criteria include its 65V switch rating, 100 kHz fixed-frequency operation, 1.24 V feedback reference, TO-263-5 package thermal performance (θJA = 45°C/W), and compatibility with LT1171/LM2577 socket footprints.
Technical Context
The MIC2171BU TR implements current-mode control using an internal transconductance error amplifier (gm = 3.9 µA/mV typ.), 1.24 V precision bandgap reference, and 100 kHz oscillator with ~90% max duty cycle. Its floating switch architecture enables flexible topology support without requiring external high-side drivers.
It integrates anti-saturation circuitry to extend usable duty cycle, provides COMP pin access for loop compensation, soft-start, and current-limit tailoring, and uses internal cycle-by-cycle current sensing to eliminate a right-half-plane pole in boost designs - simplifying stability compensation versus voltage-mode alternatives.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switch Rating | 65 V collector-emitter breakdown, 2.5 A peak current - supports 50W off-line boost and isolated flyback designs with margin. |
| Input Voltage Range | 3.0 V to 40 V - enables direct operation from single Li-ion (3.0 V min) to industrial 36 V rails. |
| Switching Frequency | 100 kHz ±12 kHz - fixed frequency simplifies EMI filtering; twice LM2577's base frequency improves power density. |
| Feedback Reference | 1.24 V ±24 mV (–40°C to +85°C) - sets output voltage via external resistor divider; line regulation ≤0.6%/V ensures stability across input range. |
| Quiescent Current | 7 mA typ. at 3–40 V - enables >100-hour runtime in 500 mAh battery-powered handheld instruments. |
| Thermal Resistance | θJA = 45°C/W (TO-263-5) - allows 1.3 W total dissipation at 70°C ambient before reaching 125°C junction limit. |
| Operating Temperature | –40°C to +85°C ambient - qualified for industrial and portable computing environments. |
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 external current-limit clamping. |
| 2 - FB | Inverting input of error amplifier | Connects to mid-point of output voltage divider; senses regulated output with 1.24 V reference threshold. |
| 3 - GND | Power and signal ground | Must connect directly to input filter capacitor ground to minimize noise coupling into sensitive analog circuitry. |
| 4 - SW | Collector of internal NPN switch | High-current switching node; connects to inductor (boost), transformer primary (flyback), or diode anode (inverting). |
| 5 - IN | Supply input | Accepts 3–40 V DC; powers internal bias circuits and switch driver; requires local 47 µF ceramic or low-ESR electrolytic bypass. |
Key Features
| Feature | Design Value |
|---|---|
| Current-mode control | Eliminates right-half-plane zero in boost converters, enabling single-pole compensation and stable operation with minimal external components. |
| Internal 65V/2.5A NPN switch | Enables compact 50W boost/flyback designs without external MOSFET; eliminates gate-drive complexity and layout sensitivity. |
| Anti-saturation circuitry | Reduces stored charge in internal transistor, extending effective duty cycle to 90% and improving efficiency in high-VIN applications. |
| Low 7 mA quiescent current | Extends battery life in palmtop computers and handheld test equipment where standby power budget is <10 mA. |
| TO-263-5 footprint compatibility | Fits standard LT1171/LM2577 PCB layouts - enables drop-in upgrade path with no board re-spin required. |
Applications
| Laptop Auxiliary Power Supply | Battery-Powered Handheld Instrument |
|---|---|
Use Scenario: Generating +12 V @ 0.25 A from a +5 V logic rail in ultraportable laptops for display backlight or peripheral interface. IC Role / Device Role / Timing Role: Primary current-mode PWM controller with integrated 65 V/2.5 A switch; regulates output via FB pin feedback and COMP-based loop compensation. Use Value: Eliminates need for external high-voltage MOSFET and driver, reducing BOM count by ≥4 components and saving >120 mm² PCB area. |
Use Scenario: Providing regulated +5 V @ 0.5 A from a 4–6 V Li-ion battery pack in portable oscilloscopes or multimeters. IC Role / Device Role / Timing Role: Flyback controller with transformer isolation; uses internal 100 kHz oscillator and current-sense loop for precise output regulation under varying load. Use Value: Achieves >82% efficiency at full load while maintaining <50 mVpp output ripple - critical for analog measurement accuracy. |
| Off-Line 50W Boost Converter | Predriver for High-Power Isolated SMPS |
Use Scenario: Stepping up 24 VDC industrial bus to 48 VDC for PoE++ or telecom subsystems, delivering up to 50 W with external power switch. IC Role / Device Role / Timing Role: Fixed-frequency (100 kHz) current-mode controller; drives external N-channel MOSFET via SW pin; FB monitors output through resistive divider. Use Value: Enables scalable design: same MIC2171BU TR controls both low-power integrated and high-power discrete implementations - simplifying qualification and inventory. |
Use Scenario: Driving gate of 100 V/30 A external MOSFET in forward converter for 12 V → 3.3 V/10 A server VRM. IC Role / Device Role / Timing Role: Predriver controller providing accurate duty-cycle-modulated base drive to external transistor; COMP pin used for current foldback protection. Use Value: Provides robust cycle-by-cycle current limiting (2.5 A peak) and thermal derating down to –40°C - ensuring reliable startup under cold ambient conditions. |
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 | 5.0 V fixed-output variant; 3.5 A switch; 52 kHz frequency; TO-220-5 only; no COMP pin access. | Limited to fixed 12 V output; lacks programmable feedback and loop compensation flexibility. | Select MIC2171BU TR when adjustable output, flyback capability, or thermal performance in SMD package is required. |
| LT1171CT#PBF | 100 kHz, 3 A switch, 60 V rating; SO-8 and TO-220 packages; no internal anti-saturation; higher IQ (10 mA). | Compatible pinout but different COMP/FB behavior; less robust under high-duty-cycle conditions. | Choose MIC2171BU TR for improved thermal resistance (TO-263), lower quiescent current, and enhanced duty-cycle headroom. |
Compared with LM2577T-12/NOPB and LT1171CT#PBF, the MIC2171BU TR offers superior adjustability (via FB/COMP), better thermal management in TO-263, and integrated anti-saturation - making it the preferred choice for new designs requiring wide input range, isolated topologies, or extended battery life.
Availability
MIC2171BU TR is available at Aetrix Electronics and suitable for laptop auxiliary power supplies, battery-operated handheld instruments, and off-line 50W boost converters requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.
Supply support for MIC2171BU 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
Microchip Technology Inc. is a leading provider of microcontrollers, analog devices, and power management ICs, serving automotive, industrial, and consumer markets with high-reliability semiconductor solutions.
The MIC2171BU TR belongs to Microchip's legacy high-voltage switching regulator controller family, engineered specifically for cost-sensitive, space-constrained DC-DC conversion in portable and industrial power systems where integration, thermal efficiency, and topology flexibility are critical.
FAQ
What is the maximum output power achievable with MIC2171BU TR in boost configuration?
The MIC2171BU TR supports up to 50W in boost topology when used with an external power switch. With its internal 65V/2.5A switch, typical continuous output is [email protected] (3W) in integrated mode. Higher power requires external MOSFET driven by the SW pin, leveraging the MIC2171BU TR's current-mode control and 100 kHz oscillator for stable regulation.
Does MIC2171BU TR support flyback converter designs?
Yes, the MIC2171BU TR is explicitly validated for flyback operation, as shown in Figure 2-2 of DS20006355A. Its floating switch architecture, 100 kHz fixed frequency, and internal current limiting enable reliable isolated [email protected] designs. External components include transformer T1 (1.8:1), Schottky output diode D2 (1N5818), and RC snubber for leakage inductance suppression.
What is the purpose of the COMP pin on MIC2171BU TR?
The COMP pin on MIC2171BU TR is the output of the transconductance error amplifier. It serves three key functions: (1) loop compensation via RC network to GND or FB, (2) soft-start via capacitor discharge control, and (3) current limit tailoring via external voltage clamp. Its high-impedance nature allows easy external adjustment without loading the internal amplifier.
Can MIC2171BU TR replace LM2577 in existing TO-220 layouts?
Yes - the MIC2171BU TR in TO-263-5 (U suffix) is pin-compatible with LM2577 in TO-220-5 (T suffix) for IN, SW, GND, FB, and COMP pins. The tab is GND in both packages. However, thermal performance differs: TO-263 offers identical θJA (45°C/W) in horizontal mounting, enabling direct replacement without derating if PCB copper area meets Microchip's 2 in² recommendation.
What is the minimum input voltage for MIC2171BU TR at –40°C?
The MIC2171BU TR maintains operation down to 2.7 V at 25°C and 3.0 V across the full –40°C to +85°C range, per Electrical Characteristics table on page 3 of DS20006355A. At –40°C, VIN(MIN) = 3.0 V ensures reliable start-up and regulation in cold-environment battery applications such as outdoor instrumentation.
MIC2171BU TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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
MIC2171BU TR FAQ
1.How can I place an order for MIC2171BU TR through Aetrix?
Please submit a Request for Quotation (RFQ) for MIC2171BU 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 MIC2171BU TR reliable?
The price and inventory of MIC2171BU TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MIC2171BU TR is usually 5 days.
3.What payment methods are accepted for MIC2171BU TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MIC2171BU TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MIC2171BU TR?
MIC2171BU TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MIC2171BU 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 MIC2171BU TR?
For technical support, including MIC2171BU TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MIC2171BU TR requirements.
6.How does Aetrix verify that MIC2171BU TR is sourced from the original manufacturer or authorized distributors?
All MIC2171BU 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 MIC2171BU TR meets industry standards.
7.What is the process for return or replacement of MIC2171BU TR?
All MIC2171BU TR units undergo pre-shipment inspection (PSI). If there is an issue with MIC2171BU 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 MIC2171BU TR part is unused and in its original packaging.
Return procedure for MIC2171BU TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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