500 mA, 1.5 MHz, 65V boost DC/DC converter

March 06, 2015 // By Graham Prophet
LT8570 and LT8570-1 are current mode, fixed frequency step-up DC/DC converters. The LT8570 uses an internal 500 mA, 65V switch, whereas the LT8570-1 uses a 250 mA, 65V switch. Both devices operate from an input voltage range of 2.55V to 40V, making them suitable for applications with input sources ranging from a single-cell Li-Ion to automotive inputs.

Both the LT8570 and LT8570-1 can be configured as a boost, SEPIC or inverting converter. The LT8570-1’s smaller switch enables the use of a smaller inductor in lower current applications. Both parts offer a programmable switching frequency between 200 kHz and 1.5 MHz, enabling designers to minimise external component sizes. The combination of a 3 x 3 mm DFN package (or MSOP-8E) and small external components ensures a compact footprint while minimising solution cost.

The LT8570 and LT8570-1 use internal high efficiency switches, which deliver efficiencies up to 86%. Undervoltage lockout (UVLO) is user-adjustable. A single feedback resistor sets the output voltage. Other features include external synchronisation capability, internal soft-start, thermal shutdown protection and the ability to work in inverting and SEPIC applications.

The LT8570/-1 is available in both a 3 x 3 mm DFN-8 and a thermally enhanced MSOP-8 package. Two temperature grades are available, with operation from -40°C to 125°C (junction) for the extended and industrial grades. Pricing starts at $2.25 (1000).

Linear Technology; www.linear.com/product/LT8570