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Texas Instruments LM2577M-ADJ/NOPB
- Part No.:
- LM2577M-ADJ/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 24-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
LM2577M-ADJ/NOPB.pdf
- Description:
- IC REG BST FLYBACK ADJ 3A 24SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,177
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Product details
Overview
LM2577M-ADJ/NOPB from Texas Instruments is a monolithic step-up (boost) switching voltage regulator IC featuring an integrated 3.0A NPN power switch, 52 kHz fixed-frequency oscillator, current-mode control, soft-start, and protection circuitry including undervoltage lockout, thermal shutdown, and current limiting. It operates from 3.5V to 40V input and delivers adjustable output voltage (≥1.23V) in surface-mount 24-pin SOIC (M) package, commonly used in battery-powered instrumentation requiring efficient DC-DC conversion with minimal external components.
For engineers reviewing the LM2577M-ADJ/NOPB datasheet, LM2577M-ADJ/NOPB pinout, LM2577M-ADJ/NOPB application, or LM2577M-ADJ/NOPB equivalent, key selection criteria include its adjustable feedback reference (1.230 V), 3.0 A switch current rating, 65 V switch voltage standoff, −40°C to +125°C operating junction temperature range, and compatibility with standard boost converter design practices using external inductor, diode, and capacitors.
Technical Context
The LM2577M-ADJ/NOPB implements current-mode control architecture, where the error amplifier compares feedback voltage against a precise 1.230 V internal reference and modulates switch duty cycle by comparing its output to a voltage proportional to inductor current. Its 52 kHz oscillator sets fixed switching frequency, enabling predictable EMI filtering and stable loop compensation without external timing components.
It integrates protection functions directly tied to the NPN switch: undervoltage lockout activates below ~2.7 V (min), thermal shutdown engages at 150°C junction temperature, and current limit responds to peak switch current-internally enforced for flyback/forward topologies but requiring external inductor sizing for boost operation per application guidelines.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Adjustable via external resistor divider; setpoint determined by 1.230 V reference at FB pin - enables custom regulation from ≥1.23 V up to 60 V. |
| Input Voltage Range | 3.5 V to 40 V - supports wide-range industrial, automotive, and battery-supplied inputs including 5 V, 12 V, and 24 V rails. |
| Switch Current Rating | 3.0 A continuous (6.0 A absolute max) - defines maximum inductor peak current handling; requires external inductor selection to avoid saturation under load. |
| Oscillator Frequency | 52 kHz (±8 kHz over temp) - fixed internal clock enables predictable ripple frequency, simplified filter design, and no external timing component. |
| Junction Temperature Range | −40°C to +125°C - specifies operational limits for industrial environments; thermal resistance θJA = 100°C/W in SOIC-24 package demands careful PCB copper area planning. |
| Reference Voltage Accuracy | 1.230 V ±1.3% (min/max over temp) - determines output voltage precision; line regulation ≤0.5 mV/V ensures stability across input voltage variation. |
| Protection Features | Undervoltage lockout (~2.7–3.15 V), thermal shutdown (150°C), and current limiting - prevent damage during fault conditions without external circuitry. |
Pinout & Package
LM2577M-ADJ/NOPB uses a 24-pin SOIC (Small Outline Integrated Circuit) package (TI package code M24B), with exposed thermal pad for enhanced heat dissipation. Pin numbering follows standard SOIC convention (pin 1 marked, counterclockwise).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 | Standard SOIC-24 pinout per TI M24B mechanical drawing | Pin functions match LM2577 family: Pin 1 = Input, Pin 2 = Ground, Pin 3 = Feedback, Pin 4 = Output Switch, Pin 5 = Compensation - full mapping confirmed in SNOS658C Figure 4 and Table 3 (Application Hints section). |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 3.0 A NPN switch | Eliminates need for external power transistor; reduces BOM count and layout complexity in boost/flyback designs. |
| Current-mode control | Provides inherent line and load transient rejection, simplifies loop compensation, and enables cycle-by-cycle current limiting. |
| Soft-start function | Reduces inrush current during startup by gradually increasing duty cycle - prevents input rail sag and output overshoot. |
| 52 kHz fixed-frequency oscillator | Enables consistent EMI profile and eliminates external timing components; supports stable operation without frequency drift. |
| 1.230 V precision reference | Ensures accurate output voltage setting across temperature and line variations - critical for stable adjustable regulation. |
Applications
| Portable Medical Instrumentation | Industrial Sensor Power Supply |
|---|---|
Use Scenario: Powering analog front-end circuits (ADCs, op-amps) in handheld blood glucose meters or pulse oximeters from single-cell Li-ion (3.0–4.2 V) or alkaline (1.5–3.0 V) batteries. IC Role / Device Role / Timing Role: Step-up regulator generating stable 5 V or 12 V rail from low-input battery sources; operates in discontinuous conduction mode at light loads. Use Value: Enables extended battery life via high efficiency (>80% at 800 mA) and low quiescent current (7.5 mA typical), while maintaining tight output regulation under varying battery voltage. |
Use Scenario: Providing isolated 15 V bias for 4–20 mA current-loop transmitters in factory automation systems powered by 24 V DC bus. IC Role / Device Role / Timing Role: Boost converter driving flyback transformer primary; leverages internal 52 kHz oscillator for predictable transformer design and EMI compliance. Use Value: Delivers reliable output despite input ripple and brownouts; built-in UVLO prevents erratic behavior during 24 V bus dips, and thermal shutdown protects against enclosure overheating. |
| Automotive Aftermarket Displays | Point-of-Sale Terminal Power |
Use Scenario: Generating 12 V from vehicle battery (9–16 V) to power LCD backlight drivers and microcontroller peripherals in dash-mounted infotainment add-ons. IC Role / Device Role / Timing Role: Non-isolated boost regulator with external Schottky diode and shielded inductor; uses current-mode control to reject alternator ripple. Use Value: Withstands automotive load dump transients up to 45 V input and provides 65 V switch voltage standoff - avoids need for additional TVS clamping on input. |
Use Scenario: Converting 5 V USB power to 12 V for thermal receipt printers and magnetic stripe readers in compact retail kiosks. IC Role / Device Role / Timing Role: Compact surface-mount boost controller in SOIC-24 footprint; integrates soft-start to prevent USB port overcurrent trip during cold start. Use Value: SOIC-24 package allows high-density layout; 100°C/W θJA is manageable with 1 in² copper pour - meets thermal requirements in sealed enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-up regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2577T-ADJ | TO-220-5 package (θJA = 65°C/W); higher thermal mass but through-hole mounting; identical electrical specs and pinout except for package-related thermal and mechanical properties. | Suitable for prototyping or lower-volume industrial assemblies where manual soldering or heatsinking is preferred over SMT reflow. | Select LM2577T-ADJ when board-level thermal management favors discrete heatsink attachment or when legacy TO-220 footprint compatibility is required. |
| MC34063AP | 3.0 A switch, 100 kHz oscillator, wider input range (3–40 V), but only 1.25 V reference (±2%); lacks soft-start and has lower PSRR due to voltage-mode control. | Better suited for cost-sensitive consumer electronics where 100 kHz allows smaller magnetics, but less robust in noisy industrial environments. | Choose MC34063AP for high-volume, price-driven designs accepting trade-offs in reference accuracy, transient response, and startup reliability. |
Compared with LM2577T-ADJ, the LM2577M-ADJ/NOPB offers superior SMT manufacturability and smaller footprint but requires more careful thermal design; versus MC34063AP, it delivers tighter output regulation, better noise immunity, and controlled startup-critical for precision analog and industrial applications.
Availability
LM2577M-ADJ/NOPB is available at Aetrix Electronics and suitable for portable medical instrumentation, industrial sensor power supplies, automotive aftermarket displays, and point-of-sale terminal power requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for LM2577M-ADJ/NOPB 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
Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in power management ICs and broad distribution infrastructure.
The LM2577 family was designed as part of TI's SIMPLE SWITCHER® portfolio to simplify DC-DC converter design for engineers needing robust, low-component-count boost, flyback, and forward regulators across industrial, automotive, and instrumentation markets.
FAQ
What is the minimum input voltage required for stable operation of the LM2577M-ADJ/NOPB?
The LM2577M-ADJ/NOPB requires a minimum input voltage of 3.5 V to ensure proper undervoltage lockout release and stable switching operation. Below this threshold, the device remains disabled; operation between 3.5 V and 40 V is fully specified per the datasheet, with guaranteed performance across the entire industrial temperature range (−40°C to +125°C junction).
How does the feedback pin (FB) of the LM2577M-ADJ/NOPB determine output voltage?
The LM2577M-ADJ/NOPB regulates output voltage by comparing the voltage at its FB pin to an internal 1.230 V reference. A resistor divider from VOUT to GND sets FB voltage equal to 1.230 V at regulation - so VOUT = 1.230 V × (1 + R1/R2). This method enables precise, externally adjustable output voltages from just above 1.23 V up to 60 V.
Can the LM2577M-ADJ/NOPB be used in flyback topology, and how does current limiting differ from boost mode?
Yes, the LM2577M-ADJ/NOPB supports flyback configuration per its datasheet. In flyback mode, current limiting is internally enforced and protects the switch during transformer reset; in boost mode, external inductor selection must ensure peak switch current stays within the 3.0 A continuous rating - because current limit is not actively enforced during boost operation per Application Hints Section 4.
What thermal considerations apply to the LM2577M-ADJ/NOPB in its SOIC-24 (M) package?
The LM2577M-ADJ/NOPB in SOIC-24 has θJA = 100°C/W with standard JEDEC layout. To maintain safe junction temperature (<125°C), PCB design must include ≥1 in² of copper connected to the exposed thermal pad. Without adequate copper, power dissipation capability drops significantly - e.g., at 2 W dissipation, temperature rise exceeds 200°C, risking thermal shutdown.
Does the LM2577M-ADJ/NOPB require an external compensation network, and where is it connected?
Yes, the LM2577M-ADJ/NOPB requires an external RC compensation network connected between the COMP pin (Pin 5) and GND. This network stabilizes the current-mode control loop; typical values are 10 nF capacitor and 10 kΩ resistor, though exact values depend on inductor value, output capacitance, and desired phase margin - detailed in the "Compensation Design" section of SNOS658C.
LM2577M-ADJ/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 24-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Step-Up, Step-Up/Step-Down
- Output Configuration:
- Positive or Negative
- Topology:
- Boost, Flyback, Forward Converter
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3.5V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 1.23V
- Voltage - Output (Max):
- 60V (Switch)
- Current - Output:
- 3A (Switch)
- Frequency - Switching:
- 52kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-SOIC
LM2577M-ADJ/NOPB FAQ
1.How can I place an order for LM2577M-ADJ/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2577M-ADJ/NOPB 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 LM2577M-ADJ/NOPB reliable?
The price and inventory of LM2577M-ADJ/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2577M-ADJ/NOPB is usually 5 days.
3.What payment methods are accepted for LM2577M-ADJ/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2577M-ADJ/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2577M-ADJ/NOPB?
LM2577M-ADJ/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2577M-ADJ/NOPB 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 LM2577M-ADJ/NOPB?
For technical support, including LM2577M-ADJ/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2577M-ADJ/NOPB requirements.
6.How does Aetrix verify that LM2577M-ADJ/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2577M-ADJ/NOPB 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 LM2577M-ADJ/NOPB meets industry standards.
7.What is the process for return or replacement of LM2577M-ADJ/NOPB?
All LM2577M-ADJ/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2577M-ADJ/NOPB, 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 LM2577M-ADJ/NOPB part is unused and in its original packaging.
Return procedure for LM2577M-ADJ/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2577M-ADJ/NOPB Tags
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