Texas Instruments LM2576HVSX-3.3/NOPB

Overview

LM2576HVSX-3.3/NOPB from Texas Instruments is a monolithic 3-A non-synchronous step-down DC-DC regulator in TO-263 (DDPAK) package, delivering fixed 3.3-V output with ±4% tolerance over line and load, supporting 6–60-V input range, 52-kHz fixed-frequency operation, and TTL-compatible ON/OFF control - used in industrial power supplies and motor drive bias rails.

For engineers reviewing the LM2576HVSX-3.3/NOPB datasheet, LM2576HVSX-3.3/NOPB pinout, LM2576HVSX-3.3/NOPB application, or LM2576HVSX-3.3/NOPB equivalent, key selection considerations include HV input capability (60 V max), thermal performance on PCB copper planes, cycle-by-cycle current limiting (4.2–6.9 A), shutdown quiescent current (50 µA typ), and compatibility with standard off-the-shelf inductors.

Technical Context

The LM2576HVSX-3.3/NOPB integrates a high-side NPN switch, fixed-frequency 52-kHz oscillator, error amplifier with 1.23-V internal reference, and thermal shutdown circuitry. Its non-synchronous architecture requires an external catch diode and operates in continuous or discontinuous conduction mode depending on load and inductor value.

It implements undervoltage lockout via external circuitry, supports delayed start-up using RC timing on the ON/OFF pin, and reduces switching frequency to ~11 kHz during overload or short-circuit to limit average power dissipation - all while maintaining regulation within ±4% across −40°C to +125°C junction temperature.

Key Specifications

Pinout & Package

LM2576HVSX-3.3/NOPB uses the KTT (DDPAK/TO-263-5) surface-mount package with 10.16 mm × 8.42 mm body size and exposed thermal pad connected internally to GND - requires ≥1.6 in² PCB copper area for optimal θ_JA = 32°C/W performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down regulator applications.

Compared with LM2576SX-3.3/NOPB, the LM2576HVSX-3.3/NOPB adds 20-V input headroom critical for 48-V systems with transients; versus LMR51430RNXR, it trades efficiency and integration for ruggedness, simplicity, and legacy compatibility - making it preferred for cost-sensitive, high-reliability industrial applications.

Availability

LM2576HVSX-3.3/NOPB is available at Aetrix Electronics and suitable for industrial motor drives, merchant network PSUs, appliance control boards, test equipment, and other applications requiring stable component supply with extended input voltage tolerance and proven thermal robustness.

Supply support for LM2576HVSX-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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The LM2576HVSX-3.3/NOPB belongs to TI's SIMPLE SWITCHER® power converter family - designed specifically for engineers seeking easy-to-use, highly reliable, and thermally robust DC-DC conversion without complex compensation or layout constraints.

FAQ

What is the maximum input voltage rating for LM2576HVSX-3.3/NOPB?

The LM2576HVSX-3.3/NOPB has an absolute maximum input voltage of 63 V and a recommended operating maximum of 60 V - confirmed in Section 6.1 Absolute Maximum Ratings and Section 6.3 Recommended Operating Conditions of the official TI datasheet SNVS107G. This HV rating distinguishes it from the standard LM2576 (40-V max) and enables use in 48-V systems with transient margins. Exceeding 60 V continuously risks thermal overstress or premature failure.

Does LM2576HVSX-3.3/NOPB require an external feedback resistor network?

No, the LM2576HVSX-3.3/NOPB does not require external feedback resistors because it is a fixed-output variant - its internal feedback divider is factory-trimmed to regulate precisely at 3.3 V. As stated in Section 5 Pin Functions and Figure 5-2, Pin 4 (FEEDBACK) is internally connected to the output, eliminating external components. This simplifies layout, improves long-term accuracy, and removes resistor tolerance and temperature drift as error sources.

What thermal performance can be expected from LM2576HVSX-3.3/NOPB in TO-263 package?

In the KTT (TO-263) package, LM2576HVSX-3.3/NOPB achieves θ_JA = 42.6°C/W on JEDEC 4-layer board per Section 6.4 Thermal Information. With ≥1.6 in² of PCB copper connected to the exposed thermal tab, θ_JA improves to 32°C/W - enabling 3-A operation at up to +70°C ambient without a heatsink. Thermal shutdown activates at 150°C junction temperature, providing fault protection during overload or poor airflow conditions.

How does the ON/OFF pin function on LM2576HVSX-3.3/NOPB?

The ON/OFF pin (Pin 5) of LM2576HVSX-3.3/NOPB provides TTL-compatible enable control: logic low (<1.2 V) enables regulation, logic high (>1.4 V) forces shutdown with 50-µA typical standby current. As detailed in Section 7.4.1 and Table 5-1, this pin supports firmware-controlled power sequencing, delayed start-up via RC networks, and system-level sleep modes - all without external level shifters or pull-up resistors.

Is LM2576HVSX-3.3/NOPB RoHS-compliant and lead-free?

Yes, LM2576HVSX-3.3/NOPB is RoHS-compliant and lead-free - indicated by the "/NOPB" suffix per TI's packaging nomenclature (NOPB = No Lead, Pb-Free). The device meets J-STD-020 moisture sensitivity level 3 and is qualified for reflow soldering per IPC/JEDEC J-STD-020. Full compliance documentation, including material declarations and test reports, is available in TI's official product folder and Quality & Environmental Information portal.