Texas Instruments LM330T-5.0

Overview

LM330T-5.0 from National Semiconductor is a 3-terminal positive low-dropout linear voltage regulator delivering 5.0 V ±2% output with 150 mA load capability, 0.32–0.6 V dropout at full load, and reverse-battery protection-designed for battery-powered systems where input voltage may fall to 5.6 V while maintaining regulation.

For engineers reviewing the LM330T-5.0 datasheet, LM330T-5.0 pinout, LM330T-5.0 application, or LM330T-5.0 equivalent, key selection considerations include dropout voltage under 0.6 V, line transient shutdown at 40 V, thermal overload protection, and TO-220 package compatibility with standard heat sinking in portable instrumentation and industrial control power rails.

Technical Context

The LM330T-5.0 uses a lateral PNP pass transistor architecture-distinct from NPN-based regulators-to achieve sub-0.6 V dropout and reduce thermal dissipation. Its internal current limiting (150–700 mA) and thermal shutdown activate independently of external components.

It integrates reverse-polarity protection (survives −6 V input), mirror-image insertion tolerance, and overvoltage shutdown at 26–38 V, with output disabling during 40 V/1 s transients to prevent downstream damage. Ripple rejection is 56 dB at 120 Hz.

Key Specifications

Pinout & Package

LM330T-5.0 is housed in a TO-220 plastic package (National Semiconductor package code T03B), with vertical mounting orientation, metal tab electrically connected to the output terminal, and standard 0.1" pin spacing compatible with PCB through-hole layouts and heatsink clamping.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout positive voltage regulator applications.

Compared with LM2931T-5.0 and TPS73550DRBT, the LM330T-5.0 uniquely combines reverse-battery survival, mirror-image tolerance, and 0.32 V dropout in a TO-220 package-making it optimal for cost-sensitive, battery-reliant industrial and portable designs where layout simplicity and fault resilience are prioritized over ultra-low IQ or enable functionality.

Availability

LM330T-5.0 is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, and handheld test equipment requiring stable component supply with long-term lifecycle visibility and consistent TO-220 mechanical form factor.

Supply support for LM330T-5.0 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

National Semiconductor was a U.S.-based analog semiconductor company acquired by Texas Instruments in 2011, known for high-reliability linear regulators, data converters, and interface ICs.

The LM330 product line was engineered specifically for low-input-margin battery and industrial power applications-emphasizing dropout reduction, reverse-polarity hardening, and transient survivability without external protection components.

FAQ

What is the minimum input voltage required for LM330T-5.0 to maintain regulation?

The LM330T-5.0 maintains regulation with an input voltage as low as 5.6 V under full 150 mA load, due to its 0.32–0.6 V dropout voltage. At lighter loads, regulation holds even lower-for example, 5.3 V at 10 mA. Input below 6 V should be verified against load and temperature conditions using the DS009306 datasheet curves.

Does LM330T-5.0 require external capacitors for stability?

Yes, LM330T-5.0 requires a minimum 0.1 µF ceramic capacitor at the input and a 10 µF aluminum or tantalum capacitor at the output (C2), placed close to the device. The output capacitor must be rated for −40 °C operation to guarantee stability across the full temperature range, as specified in DS009306.

Can LM330T-5.0 survive reverse battery connection?

Yes, LM330T-5.0 is explicitly designed with reverse-battery protection and survives −6 V applied to the input pin without damage or latch-up. This eliminates the need for an external series diode in battery-powered applications, reducing voltage loss and board space.

What thermal performance can be expected from LM330T-5.0 in a TO-220 package?

LM330T-5.0 has a junction-to-case thermal resistance of 4 °C/W and junction-to-ambient of 50 °C/W. With a properly mounted heatsink on the metal tab (connected to OUT), it sustains 150 mA at 26 V input without exceeding +125 °C junction temperature-verified per Absolute Maximum Ratings in DS009306.

Is LM330T-5.0 pin-compatible with other 3-terminal 5 V regulators like the 7805?

No, LM330T-5.0 is not pin-compatible with standard 78xx-series regulators. Its pinout is IN–OUT–GND (TO-220 front view), whereas 7805 uses IN–GND–OUT. Swapping them without PCB revision will cause functional failure or damage-always verify pin assignment using DS009306-2 diagram before layout reuse.