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Texas Instruments LM2599T-3.3/NOPB
- Part No.:
- LM2599T-3.3/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- TO-220-7 Formed Leads
- Datasheet:
-
LM2599T-3.3/NOPB.pdf
- Description:
- IC REG BUCK 3.3V 3A TO220-7
- Quantity:
- Payment:
- Shipping:
Inventory:3,682
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Product details
Overview
LM2599T-3.3/NOPB from Texas Instruments is a monolithic 150 kHz step-down (buck) switching voltage regulator IC delivering a fixed 3.3 V output at up to 3 A, with ±4% output voltage tolerance over line and load, 4.5–40 V input range, and integrated thermal shutdown and current limiting. It serves as a high-efficiency primary DC/DC converter in industrial power supplies and embedded system rails.
For engineers reviewing the LM2599T-3.3/NOPB datasheet, LM2599T-3.3/NOPB pinout, LM2599T-3.3/NOPB application, or LM2599T-3.3/NOPB equivalent, key selection considerations include its 3A continuous output capability, TO-220-7 package thermal performance (θJA = 50°C/W), 80 μA standby quiescent current, and compatibility with standard off-the-shelf inductors and Schottky catch diodes.
Technical Context
The LM2599T-3.3/NOPB integrates a PWM controller, power switch, error amplifier, and fixed-frequency oscillator operating at 150 kHz - enabling compact external filter design. Its two-stage current limit protects against overload while maintaining regulation during transient conditions.
It features an out-of-regulation error flag with programmable delay, shutdown/soft-start control via a dedicated pin, and internal frequency compensation - eliminating need for external compensation components. The feedback loop uses a precision 1.23 V reference for the adjustable version, but the LM2599T-3.3/NOPB implements this internally to deliver a stable 3.3 V output without external resistors.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3 V ±4% over full temperature and load range - ensures reliable logic rail compliance for 3.3 V microcontrollers and FPGAs. |
| Max Output Current | 3 A continuous - supports mid-power applications such as DSP cores, interface ICs, and sensor hubs without external current boosting. |
| Input Voltage Range | 4.5 V to 40 V - accommodates wide-input industrial, automotive, and telecom supply buses including 12 V, 24 V, and 36 V nominal systems. |
| Switching Frequency | 150 kHz fixed - enables use of low-cost, high-saturation-current inductors (e.g., 33–68 µH) and reduces EMI compared to higher-frequency alternatives. |
| Quiescent Current | 80 µA in shutdown - minimizes standby power loss in battery-backed or energy-sensitive systems. |
| Thermal Resistance | θJA = 50°C/W (TO-220), θJC = 2°C/W - allows 3 A operation with modest heatsinking at ambient ≤60°C. |
| Efficiency | 73% at 12 VIN, 3 AOUT - delivers >2 W of dissipated heat at full load, requiring thermal management planning. |
Pinout & Package
LM2599T-3.3/NOPB is housed in a 7-pin TO-220 package (NDZ0007B) with tab connected to Pin 2 (Ground). The package includes bent/staggered leads for through-hole mounting and provides mechanical robustness and thermal conduction via the exposed metal tab.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1: Input | Power input | Accepts 4.5–40 V DC; requires local 470 µF/50 V electrolytic bypass capacitor near pin to suppress input ripple and transients. |
| Pin 2: Ground | Power and signal reference | Common return for input, output, and internal circuitry; tab is electrically connected to this pin for thermal and electrical grounding. |
| Pin 3: Output | Regulated DC output | Delivers 3.3 V @ up to 3 A; connects to output inductor and catch diode anode; requires low-ESR 220 µF output capacitor. |
| Pin 4: Feedback | Voltage sense input | Internally tied to 3.3 V reference; not user-accessible on fixed-output variants - no external resistor divider needed. |
| Pin 5: Shutdown/Soft-start | Control input | Pull below 0.6 V to enter shutdown (80 µA IQ); apply 2–3 V ramp for soft-start; open for normal operation. |
| Pin 6: Flag/Delay | Error status output | Open-drain flag asserts low when output drops below 92–98% of nominal; delay capacitor sets response time. |
| Pin 7: Error Flag | Error output | Same function as Pin 6 - dual-pin configuration supports flexible PCB routing; both pins are internally paralleled. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated thermal shutdown | Activates at +150°C junction temperature and latches off until reset by cycling input or shutdown pin - prevents permanent damage under sustained overload. |
| Two-stage current limiting | First stage limits peak switch current to ~4.5 A; second stage reduces switching frequency under severe overload - maintains regulation longer than single-threshold designs. |
| Out-of-regulation error flag | Asserts low within 10–100 µs (configurable via CDELAY) when VOUT falls outside ±4% window - enables upstream fault logging or system-level brownout response. |
| Low-ESR capacitor support | Stable with aluminum electrolytic, tantalum, and polymer capacitors - avoids instability issues common with ceramic-only output filters in buck regulators. |
| Standard inductor compatibility | Optimized for off-the-shelf 33–68 µH shielded inductors (e.g., L38, L40 series) - eliminates custom magnetics and accelerates prototyping. |
Applications
| Industrial PLC Power Rail | Automotive Body Control Module |
|---|---|
Use Scenario: Supplies 3.3 V to ARM Cortex-M7 MCU, CAN transceiver, and analog front-end in a DIN-rail mounted programmable logic controller. IC Role / Device Role / Timing Role: Primary non-isolated buck regulator converting 24 V bus to clean 3.3 V logic rail with high noise immunity and thermal resilience. Use Value: Delivers 3 A continuously at 73% efficiency with built-in current limiting and thermal protection - eliminates need for external current-sense or thermal monitoring circuits. | Use Scenario: Powers infotainment SoC peripherals and LIN transceivers in a vehicle body control unit operating from 9–16 V battery supply. IC Role / Device Role / Timing Role: Step-down regulator handling cold-crank (6.5 V) to load-dump (40 V) transients while maintaining 3.3 V output stability. Use Value: Withstands 40 V max input and operates down to 4.5 V, enabling direct connection to automotive battery without pre-regulator - reduces BOM count and board space. |
| Medical Sensor Hub | Networking PoE Midspan |
Use Scenario: Provides regulated 3.3 V to low-noise ADCs, MEMS sensors, and BLE radio in a portable patient monitor. IC Role / Device Role / Timing Role: High-efficiency DC/DC converter minimizing self-heating in thermally constrained enclosures. Use Value: 80 µA shutdown current extends battery life during sleep mode; ±4% output tolerance ensures accurate sensor biasing and reference stability. | Use Scenario: Generates 3.3 V auxiliary rail from 48 V PoE midspan supply to power Ethernet PHYs and management controllers. IC Role / Device Role / Timing Role: Pre-regulator stepping 48 V down to 3.3 V before linear LDOs - improves overall system efficiency versus direct LDO conversion. Use Value: 150 kHz switching frequency allows use of small, low-cost inductors while achieving >70% efficiency - reduces heat generation in densely packed PoE equipment. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2596T-3.3/NOPB | Lower 1.5 A output current rating; same 150 kHz frequency and TO-220-5 package; lacks error flag and soft-start. | Suitable only for sub-1.5 A loads; no fault reporting or controlled startup - less suitable for safety-critical or high-reliability systems. | Select LM2596T-3.3/NOPB only if cost is primary concern and 3 A capability is unnecessary. |
| TPS5430DDAR | 3 A synchronous buck with 500 kHz switching, SOIC-8 package, and integrated high-side/low-side MOSFETs; requires external compensation. | Higher efficiency (~85%) and smaller solution size, but needs careful layout and compensation tuning - increases design complexity. | Choose TPS5430DDAR when board space is constrained and efficiency >80% is required; avoid if thermal management favors TO-220 or simplicity is critical. |
Compared with LM2596T-3.3/NOPB, the LM2599T-3.3/NOPB adds 2× output current headroom, error flag, and soft-start - making it more robust for industrial loads. Versus TPS5430DDAR, it trades higher efficiency and integration for simpler design, proven thermal behavior in TO-220, and lower component count.
Availability
LM2599T-3.3/NOPB is available at Aetrix Electronics and suitable for industrial automation, automotive electronics, and medical device power supplies requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LM2599T-3.3/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, embedded processing, and power management technologies, with decades of expertise in switching regulator design and manufacturing.
The LM2599 series was developed as part of TI's SIMPLE SWITCHER® portfolio to provide rugged, easy-to-use buck regulators for industrial, automotive, and telecom applications where reliability, thermal resilience, and minimal external component count are essential.
FAQ
What is the maximum input voltage rating for LM2599T-3.3/NOPB?
The absolute maximum input voltage for LM2599T-3.3/NOPB is 45 V, but the recommended operating range is 4.5 V to 40 V. Exceeding 40 V risks violating the specified operating conditions and may trigger internal protection or reduce reliability. The 40 V upper limit is validated across temperature and load in the Electrical Characteristics table.
Does LM2599T-3.3/NOPB require external feedback resistors?
No, LM2599T-3.3/NOPB does not require external feedback resistors. As a fixed-output variant, its 3.3 V reference is internally trimmed and connected - Pin 4 (Feedback) is not user-accessible for adjustment. This simplifies design and improves output accuracy versus adjustable versions that depend on resistor tolerance.
Can LM2599T-3.3/NOPB be used in surface-mount designs?
LM2599T-3.3/NOPB is offered only in the 7-pin TO-220 (NDZ) package, which is through-hole mountable. For surface-mount applications, TI offers the LM2599S-3.3/NOPB in TO-263 (KTW) package. The two share identical electrical specs but differ in thermal profile and assembly method - LM2599T-3.3/NOPB requires wave or hand soldering.
What is the typical efficiency of LM2599T-3.3/NOPB at full load?
LM2599T-3.3/NOPB achieves 73% typical efficiency at 12 V input and 3 A output, per the LM2599-3.3 Electrical Characteristics table. Efficiency varies with input voltage and load - e.g., it reaches ~90% at 25 VIN/3 AOUT for the 12 V version, but the 3.3 V variant peaks lower due to higher relative conduction losses at low output voltage.
How does the error flag (Pin 6/7) behave during startup?
The error flag on LM2599T-3.3/NOPB remains high-Z (open) during soft-start and asserts low only after output reaches regulation and remains within ±4% of 3.3 V for the delay period set by the external CDELAY capacitor. It does not assert during normal startup - only upon sustained dropout, overcurrent, or thermal fault.
LM2599T-3.3/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- TO-220-7 Formed Leads
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4.5V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 3A
- Frequency - Switching:
- 150kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220-7
LM2599T-3.3/NOPB FAQ
1.How can I place an order for LM2599T-3.3/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2599T-3.3/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 LM2599T-3.3/NOPB reliable?
The price and inventory of LM2599T-3.3/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2599T-3.3/NOPB is usually 5 days.
3.What payment methods are accepted for LM2599T-3.3/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2599T-3.3/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2599T-3.3/NOPB?
LM2599T-3.3/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2599T-3.3/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 LM2599T-3.3/NOPB?
For technical support, including LM2599T-3.3/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2599T-3.3/NOPB requirements.
6.How does Aetrix verify that LM2599T-3.3/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2599T-3.3/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 LM2599T-3.3/NOPB meets industry standards.
7.What is the process for return or replacement of LM2599T-3.3/NOPB?
All LM2599T-3.3/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2599T-3.3/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 LM2599T-3.3/NOPB part is unused and in its original packaging.
Return procedure for LM2599T-3.3/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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