LM2578AM

Voltage Regulators - DC DC Switching Regulators Overview

The LM2578AM is a monolithic integrated circuit from the LM2578 series, functioning as a switching regulator control circuit manufactured by Texas Instruments. It integrates a power switch transistor and an oscillator to support Buck, Boost, and Inverting DC-DC converter topologies. The device operates with an input voltage range of 2V to 40V and provides a maximum output current of 750mA. The internal oscillator frequency is adjustable via an external capacitor, ranging from 1Hz to 100kHz. It features a 1.0V reference voltage, independent inverting/non-inverting inputs, and built-in overcurrent limiting and thermal shutdown protection. The 'A' suffix indicates an extended temperature rating of -40°C to +125°C.

Voltage Regulators - DC DC Switching Regulators Feature Summary

• Integrates a high-voltage power switch transistor capable of handling up to 40V collector voltage.
• Supports versatile DC-DC conversion topologies including step-down, step-up, and voltage inversion.
• Includes comprehensive protection mechanisms such as current limiting and thermal shutdown.
• Features an internally compensated oscillator for stable switching frequency operation.

Voltage Regulators - DC DC Switching Regulators Applications

• Battery-powered equipment requiring efficient voltage regulation
• Distributed power supply systems
• RS-232 power configurations
• High-efficiency step-down converters

Voltage Regulators - DC DC Switching Regulators Procurement Notes

Verify the specific manufacturer source, as the LM2578 family originated with National Semiconductor before being transferred to Texas Instruments. Confirm that the 'AM' suffix correctly denotes the military/extended temperature grade (-40°C to +125°C) and SOIC-8 package. Ensure compatibility with required switching frequencies and external component selections for the intended topology.

Voltage Regulators - DC DC Switching Regulators Selection Notes

Select this component when a fixed-frequency switching controller is needed for moderate current applications up to 750mA. It is suitable for designs requiring both positive and negative output voltages from a single input source. Consider the thermal management requirements due to the internal power switch dissipation. Compare against the LM2576 or LM2596 if higher output currents are required.

Voltage Regulators - DC DC Switching Regulators Part Context

The LM2578 belongs to the LM25xx family of simple-switcher regulators, designed for ease of use with minimal external components. Unlike the LM2576 which includes the control circuitry and switch in a single package, the LM2578 is primarily a controller that may require external configuration depending on the specific implementation, though it integrates the main power switch. It serves as a foundational solution for cost-sensitive power management designs.

Voltage Regulators - DC DC Switching Regulators Replacement Considerations

LM2578ADJ: Adjustable output version of the same series. LM2576-ADJ: Integrated regulator with adjustable output. LM2596-ADJ: Higher current capability (3A) successor. Verify pinout compatibility and thermal performance when substituting.

Voltage Regulators - DC DC Switching Regulators FAQ

What is the maximum operating junction temperature for the LM2578AM?

The LM2578AM is rated for a maximum operating temperature of +125°C, distinguishing it from the commercial LM2578 variant which is typically rated up to +85°C.

Can the LM2578AM generate a negative output voltage?

Yes, the device supports inverting (negative output) topology configurations using its independent inverting input pin and appropriate external diode and inductor selection.