Power IC voltage regulator Texas Instruments LM2577T-ADJ/NOPB — adjustable DC/DC switching regulator, boost/flyback/forward, TO-220-5

The Texas Instruments LM2577T-ADJ/NOPB is an adjustable DC/DC switching regulator in a TO-220-5 package designed for boost, flyback and forward converter topologies. This power IC delivers switched-mode regulation with an externally adjustable output, enabling step-up and isolated converter designs. It is intended for use in power supply design and battery-powered systems where an efficient, configurable boost regulator is required.

Advantages

The device provides adjustable output voltage through external resistors and components, allowing precise regulation across a range of applications. Its TO-220-5 package offers ease of mounting and thermal handling for moderate power levels. Designed for multiple converter topologies (boost, flyback, forward), the regulator supports flexible circuit topologies and helps simplify designs that require step-up or isolated outputs. The integrated switching controller reduces component count compared with discrete implementations.

Suitable for

• Design of step-up (boost) power supplies
• Flyback and forward isolated converter designs
• Battery-powered systems needing an adjustable DC/DC boost stage
• Industrial power converters and embedded power modules

Key specifications

• Topology support: boost, flyback, forward converter
• Output: externally adjustable via resistive network and components
• Package type: TO-220-5, suitable for through-hole mounting
• Function: switching regulator (step-up / boost and isolated converter control)
• Application domain: power supply design, battery systems, industrial converters

How to use

Implement the LM2577T-ADJ/NOPB by following the converter topology recommended for the intended application (boost, flyback or forward). Select the inductor, diode, capacitors and the feedback resistor network to set the required output voltage and to meet current and ripple specifications. Mount the TO-220-5 package on a board with adequate copper area or a heatsink if increased thermal dissipation is expected. Observe standard layout practices for switching regulators: keep high-current loops short, place the input and output capacitors close to the device, and provide a stable ground return.

Recommendations

Use the regulator within its specified input voltage and load current ranges, and follow the manufacturer’s recommended component values and PCB layout guidelines to ensure stable operation and reliable thermal performance. For battery-powered applications, verify startup behaviour and efficiency across the expected input range.