Output current limiting function

October 12, 2011 – Linear Technology Korea (General Manager Hong Sa-kwak, www.linear.com ) announced the release of the 36V input constant frequency step-down µModule® regulator (product name: LTM8052) capable of adjusting the output current limit up to 5A.
The adjustable current limiting function allows system designers to set the maximum power delivered to the load, thereby minimizing the rated output of the upstream AC/DC or DC/DC power supply. In addition, the LTM8052 can regulate the adjustable output voltage while sourcing or sinking current.
For simple noise filtering, the LTM8052 operates at a constant frequency across the entire output current range. This µModule regulator converts input voltages ranging from 6V to 36V into adjustable output voltages from 1.2V to 24V. For 12V input-2.5V output applications, the LTM8052 achieves a peak operating efficiency of 88% at 2A.
Major applications include industrial, medical imaging and communication PoL, charge balancing and Peltier thermoelectric module drivers.

The LTM8052's 10% precision current limiting feature is an improvement over conventional step-down regulators that limit current approximately 40–50% above the actual output current. Using the LTM8052 enables the installation of low-power and low-cost upstream power supplies. Otherwise, higher output power may be required to prevent voltage rails from collapsing under overcurrent or short-circuit conditions.
The current limiting function also enables temperature compensation using a thermistor, further enhancing thermal management capabilities. In the case of current sinking, this µModule regulator transfers the sinking energy to the input rail rather than dissipating it as heat as in conventional methods. For noise-sensitive applications, the LTM8052 can be synchronized to an external clock frequency in the range of 100 kHz to 1 MHz. Other features include externally adjustable soft start, adjustable switching frequency, and thermal shutdown.

The LTM8052 is available in a highly thermally efficient 11.25mm x 15mm x 2.82mm LGA package. It comes in two temperature ratings, E and I, with a temperature range of -40°C to +125°C. It is available for immediate purchase. Pricing starts at $13.17 per unit for 1,000 units.
For more information, please refer to www.linear.com/product/LTM8052 .

Photo caption: 36VIN, ±5A source/sink step-down µModule® regulator with adjustable current limit

Product Features: LTM8052

• Current limit accuracy adjustable by ±10%
• CCM operation under light load
• 6V ~ 36V input voltage range
• Output voltage range of 1.2V to 24V
• Output current sourcing up to +5A / Output current sinking up to -7A
• 88% efficiency (12VIN ~ 2.5VOUT)
• Adjustable FSW 100kHz – 1MHz
• Synchronize with an external clock of 100kHz to 1MHz
• Compact 11.25 × 15 × 2.82mm LGA package with enhanced thermal performance