Source/sink step-down regulator offers adjustable current limit benefits

October 12, 2011 // Paul Buckley

Linear Technology has introduced a 36 V input constant frequency step-down µModule regulator with an adjustable output current limit up to 5 A. The adjustable current limit helps system designers set the maximum power delivered to a load, minimizing the output rating of the upstream AC/DC or DC/DC power supply.

Additionally, the LTM8052 is capable of sourcing or sinking current while regulating an adjustable output voltage. For simple noise filtering, the LTM8052 operates at a constant frequency throughout the entire output current range.

The µModule regulator converts an input voltage between 6 V and 36 V to an adjustable output voltage between 1.2 V to 24V. In a 12 V input to 2.5 V output application, the LTM8052 achieves a peak operating efficiency of 88% at 2 A. Applications include industrial, medical imaging and communications point of load, charge balancing and Peltier thermoelectric module drivers.

The LTM8052’s 10% accurate current limit is an improvement compared with traditional step-down regulators whose current limit can be 40%-50% greater than the actual output current. With the LTM8052, a lower power and less costly upstream power supply can be installed, which would otherwise require a greater output power rating to prevent a collapse of the voltage rail under an overcurrent or short-circuit condition.

The current limit may also be compensated for temperature using a thermistor for improved thermal management. When sinking current, the µModule regulator recovers energy, transferring it to the input rail rather than dissipating it as heat 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. Additional features include externally adjustable soft start, adjustable switching frequency and thermal shutdown.

Availability and Pricing

The LTM8052 is packaged within a thermally efficient 11.25 mm x 15 mm x 2.82 mm LGA package. The two temperature grades, E and I for the -40 to +125°C temperature range, are available for immediate delivery from stock. Pricing starts at $13.17 each for 1,000-piece quantities.

More information about the LTM8052 at
www.linear.com/product/LTM8052

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December 15, 2011 | Texas instruments | 222901974

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