The LT3581 is a PWM DC/DC converter with built-in fault protection to help protect output short circuits, input/output overvoltage and overtemperature conditions. The unit consists of a 42V master switch and a 42V slave switch that can be connected together with a total current limit of 3.3A.
Typical application
The LT3581 is ideal for many local power supply designs. It can be easily configured in boost, SEPIC, inverter or flyback configurations, and is capable of producing 12V at 830mA, or -12V at 625mA from 5V inputs. In addition, the LT3581's slave switch allows parts to be configured with a high-voltage, high-power charge-pump topology that is highly efficient and requires fewer components than conventional circuits.
Pin arrangement
The LT3581's switching frequency range can be set between 200kHz and 2.5MHz. The unit can be internally clocked at the frequency set by the resistance from the RT pin to ground, and can also be synchronized with the external clock. The buffered version of the clock signal is driven by CLKOUT pins and can be used to sync other compatible switching regulator ics to the LT3581.
Block diagram
The LT3581 also features an innovative SHDN pin circuit that allows for slowly changing input signals and an adjustable undervoltage locking feature. Additional features such as frequency folding and soft boot integration. The LT3581 is available in 14-pin 4mm x 3mm DFN and 16-lead MSE packages.
State diagram
