DC/DC converter operates as LED driver

Linear Technology has announced the LT3592, a 36V step-down DC/DC converter designed to operate as a constant-current LED driver.

Its internal 36V, 900mA switch enables it to drive up to six 500mA white LEDs in a single string from a 36V input, for industrial and LED signage applications.

It can also drive two 500mA LEDs from a 12V lead acid battery input for automotive applications.

Series connection of the LEDs provides identical LED currents, resulting in uniform brightness and eliminating the need for ballast resistors.

The LT3592's switching frequency can be adjusted from 400kHz to 2.2MHz via a single resistor.

This enables designers to set the switching frequency above critical frequency bands such as AM radio while minimising external component size.

Offered in a 2mm x 3mm DFN-10 or MSOP-10 package, the LT3592 provides a very compact 500mA LED driving device.

LED current levels of either 10 per cent or 100 per cent of the programmed value are selectable by driving the LT3592's Bright pin.

The LT3592 uses a fixed-frequency, high side sense, current-mode architecture that provides fast transient response and cycle-by-cycle current limiting.

Other features include shorted and open LED protection, single-wire LED capability and thermal shutdown.

The LT3592EDDB and LT3592EMSE are both available from stock in 2mm x 3mm DFN-10 or MSOP-10E packages, respectively, in 1,000-piece quantities.

For applications requiring a wider temperature range, I-grade versions, namely the LT3592IDDB and LT3592IMSE, are also available from stock.

Back to top