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Microchip Technology LM2575-3.3YN
- Part No.:
- LM2575-3.3YN
- Manufacturer:
- Microchip Technology
- Package:
- 16-DIP (0.300", 7.62mm)
- Datasheet:
-
LM2575-3.3YN.pdf
- Description:
- IC REG BUCK 3.3V 1A 16DIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,275
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Product details
Overview
LM2575-3.3YN from Micrel is a monolithic 52kHz fixed-output buck switching regulator delivering 3.3V at up to 1A, with ±3% output voltage tolerance over line and load, 4V–40V input range, and integrated thermal shutdown and cycle-by-cycle current limiting. It replaces linear regulators in industrial power supplies requiring compact, high-efficiency DC-DC conversion.
For engineers reviewing the LM2575-3.3YN datasheet, LM2575-3.3YN pinout, LM2575-3.3YN application, or LM2575-3.3YN equivalent, key selection criteria include guaranteed 1A output current, TO-220 package thermal performance (θJA = 65°C/W), 52kHz fixed-frequency operation, and compatibility with standard off-the-shelf inductors for rapid design implementation.
Technical Context
The LM2575-3.3YN integrates a 52kHz oscillator, error amplifier, 1A NPN switch, internal 1.23V bandgap reference, and protection circuitry including thermal shutdown and peak-current limiting. Its feedback loop is internally compensated, eliminating external compensation components.
It operates in continuous conduction mode with a maximum duty cycle of 98%, supports external ON/OFF control via pin 5 (logic-compatible with 1.4V/2.2V thresholds), and maintains regulation down to 4V input-enabling use in 5V and 12V bus systems with brown-out resilience.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±3% over 0.2A–1A load and 8V–40V input - ensures stable logic supply for microcontrollers and FPGAs. |
| Max Output Current | 1A DC - supports single-rail digital loads without external current boosting. |
| Input Voltage Range | 4V to 40V - accommodates 5V, 12V, and 24V industrial rails with margin for transients. |
| Switching Frequency | 52kHz ±10% - enables use of low-cost, high-saturation-current inductors (e.g., 330µH) and reduces EMI filtering complexity. |
| Efficiency | 75% at 12VIN/3.3VOUT/1A - cuts heat dissipation vs. linear regulators, often eliminating need for heatsink. |
| Standby Current | <200µA when ON/OFF pin = 5V - enables low-power sleep modes in battery-backed systems. |
| Protection Features | Thermal shutdown + cycle-by-cycle current limit - prevents damage during short-circuit or overload without external sensing. |
Pinout & Package
LM2575-3.3YN uses the 5-pin TO-220 package (suffix 'T'), with exposed tab electrically connected to Pin 3 (GND) for thermal conduction. Mounting requires mechanical isolation if GND is not chassis-connected.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: VIN | Unregulated input supply connection | Accepts 4V–40V DC; must be decoupled with ≥100µF electrolytic capacitor near pin. |
| 2: OUTPUT | Switched output node driving external inductor | Connects to inductor input; carries pulsed 1A current - layout requires short, wide trace to minimize ringing. |
| 3: GND | Power and signal ground reference | Common return for input cap, output cap, and feedback divider; tied to exposed tab for thermal path. |
| 4: FB | Feedback input (not used in fixed-output version) | Internally connected to 3.3V output; left unconnected - no external resistor divider required. |
| 5: ON/OFF | Logic-controlled enable/disable input | Drives internal comparator: <1.0V = ON, >2.2V = OFF; pulls to GND via 10kΩ for default-on operation. |
Key Features
| Feature | Design Value |
|---|---|
| Fixed 3.3V output | Eliminates external feedback resistors - reduces BOM count and layout sensitivity for dedicated 3.3V rail generation. |
| Integrated 1A NPN switch | Removes need for external MOSFET and driver - simplifies design and improves reliability in space-constrained applications. |
| Internal frequency compensation | Enables stable operation with only four external components (input cap, output cap, inductor, catch diode) - accelerates prototyping. |
| Thermal shutdown + current limit | Provides self-protection under sustained overload or ambient temperature rise - avoids system-level fault propagation. |
| 52kHz fixed oscillator | Optimizes inductor size and core loss trade-off - supports cost-effective, shielded drum-core inductors instead of high-frequency RF types. |
Applications
| Industrial PLC I/O Power | Embedded Microcontroller Supply |
|---|---|
|
Use Scenario: Providing regulated 3.3V power to digital I/O modules in programmable logic controllers operating from 24V DC field buses. IC Role / Device Role / Timing Role: Primary step-down regulator converting 24V bus to isolated 3.3V logic rail with transient immunity. Use Value: Delivers 1A continuously at 75% efficiency, reducing thermal load in sealed enclosures where forced air cooling is unavailable. |
Use Scenario: Powering ARM Cortex-M or RISC-V microcontrollers and associated peripherals (SPI flash, sensors) on compact PCBs. IC Role / Device Role / Timing Role: Single-chip DC-DC converter replacing inefficient LDOs to extend battery life or reduce board area. Use Value: Achieves 3.3V ±3% accuracy across –40°C to +85°C, ensuring reliable reset and ADC reference stability without trimming. |
| Motor Drive Logic Supply | Legacy System Voltage Translation |
|
Use Scenario: Generating clean 3.3V for gate drivers and MCU logic in brushed DC motor controllers powered by 12V automotive batteries. IC Role / Device Role / Timing Role: Pre-regulator upstream of low-noise LDOs, rejecting battery ripple and load dump transients. Use Value: Withstands 40V input surges and maintains regulation down to 4V - survives cold-crank conditions without brownout. |
Use Scenario: Upgrading legacy 5V-only systems to support modern 3.3V peripherals (USB PHYs, Ethernet MACs) without redesigning entire power tree. IC Role / Device Role / Timing Role: Drop-in replacement for obsolete 78L33 linear regulators, using same footprint and input/output caps. Use Value: Reduces heat sink requirement by >90% versus linear solution - enables retrofit into thermally constrained chassis. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2575-3.3WT | Pb-free RoHS-compliant version of same TO-220 device; identical electrical specs and pinout. | No functional difference - selected when lead-free compliance is mandatory per IPC-J-STD-020 or customer directive. | Choose LM2575-3.3WT for new designs requiring RoHS certification; LM2575-3.3YN remains valid for legacy or non-RoHS environments. |
| LM2596-3.3 | Higher 150kHz switching frequency, 3A output rating, and improved efficiency (~88% at 12VIN/3.3VOUT); different pinout and external compensation required. | Supports higher current and smaller passive components but demands more complex layout and stability analysis. | Select LM2596-3.3 only when >1A load or tighter size constraints justify redesign; LM2575-3.3YN offers proven simplicity for ≤1A applications. |
Compared with LM2575-3.3WT, the LM2575-3.3YN shares identical performance but lacks Pb-free certification; versus LM2596-3.3, it trades higher current and frequency for lower design complexity and fewer external components - making it optimal for cost-sensitive, volume industrial power supplies where 1A suffices.
Availability
LM2575-3.3YN is available at Aetrix Electronics and suitable for industrial automation, embedded computing, and motor control applications requiring stable component supply, long-term lifecycle assurance, and consistent parametric performance across production batches.
Supply support for LM2575-3.3YN 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 headquartered in San Jose, CA, specializing in power management, timing, and interface ICs before its acquisition by Microchip Technology in 2015.
The LM2575 series was designed as a drop-in, high-efficiency replacement for three-terminal linear regulators in industrial and embedded power supplies - prioritizing simplicity, ruggedness, and minimal external component count.
FAQ
What is the maximum input voltage rating for LM2575-3.3YN?
The LM2575-3.3YN has an absolute maximum input voltage of 45V, with recommended continuous operation up to 40V. Operation above 40V risks exceeding internal transistor breakdown limits and is not guaranteed by specification. For 48V systems, consider input clamping or pre-regulation before the LM2575-3.3YN input pin.
Does LM2575-3.3YN require an external feedback resistor network?
No. The LM2575-3.3YN is a fixed-output variant - its feedback node (Pin 4) is internally connected to the 3.3V output. No external resistors are needed, unlike adjustable versions such as LM2575-ADJ. This eliminates tuning errors and improves long-term output voltage stability.
Can LM2575-3.3YN be used in negative-output configurations?
Yes - the LM2575-3.3YN can be configured as an inverting buck-boost converter to generate negative voltages. In this topology, the output ground becomes the negative rail, and the input ground serves as the negative reference. Layout must maintain tight coupling between inductor, diode, and output capacitor to minimize noise.
What thermal derating applies to LM2575-3.3YN at 85°C ambient?
With θJA = 65°C/W (TO-220, minimal copper), junction temperature rise at 1A is ~65°C. At 85°C ambient, TJ reaches ~150°C - triggering thermal shutdown. Derate output current to ~0.7A for continuous operation at 85°C ambient, or add a heatsink to reduce θJA.
Is LM2575-3.3YN pin-compatible with LM2575-5.0YN?
Yes - both LM2575-3.3YN and LM2575-5.0YN use identical 5-pin TO-220 packages and pinouts (VIN, OUTPUT, GND, FB, ON/OFF). They are electrically interchangeable at the board level; only the output voltage differs. No PCB changes are required when swapping between fixed-output variants of the same package.
LM2575-3.3YN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 16-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 1A
- Frequency - Switching:
- 52kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 16-DIP
LM2575-3.3YN FAQ
1.How can I place an order for LM2575-3.3YN through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2575-3.3YN 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 LM2575-3.3YN reliable?
The price and inventory of LM2575-3.3YN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2575-3.3YN is usually 5 days.
3.What payment methods are accepted for LM2575-3.3YN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2575-3.3YN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2575-3.3YN?
LM2575-3.3YN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2575-3.3YN 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 LM2575-3.3YN?
For technical support, including LM2575-3.3YN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2575-3.3YN requirements.
6.How does Aetrix verify that LM2575-3.3YN is sourced from the original manufacturer or authorized distributors?
All LM2575-3.3YN 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 LM2575-3.3YN meets industry standards.
7.What is the process for return or replacement of LM2575-3.3YN?
All LM2575-3.3YN units undergo pre-shipment inspection (PSI). If there is an issue with LM2575-3.3YN, 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 LM2575-3.3YN part is unused and in its original packaging.
Return procedure for LM2575-3.3YN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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