3-A, 85-V, 2.2-MHz wide VIN boost, flyback, & SEPIC converter with dual random spread spectrum

The LM5158x device is a wide input range, non-synchronous boost converter with an integrated 85-V, 3.26-A (LM5158) or 85-V, 1.63-A (LM51581) power switch.

The device can be used in boost, SEPIC, and flyback topologies. It can start up from a single-cell battery with a minimum of 3.2 V. It can operate with the input supply voltage as low as 1.5 V if the BIAS pin is greater than 3.2 V.

The BIAS pin operates up to 60 V (65-V absolute maximum). The switching frequency is dynamically programmable from 100 kHz to 2.2 MHz with an external resistor. Switching at 2.2 MHz minimizes AM band interference and allows for a small solution size and fast transient response. The device provides a selectable Dual Random Spread Spectrum to help reduce the EMI over a wide frequency range.

The device features an accurate peak current limit over the input voltage, which avoids overdesigning the power inductor. Low operating current and pulse-skipping operation improve efficiency at light loads.

The device has built-in protection features such as overvoltage protection, line UVLO, thermal shutdown, and selectable hiccup mode overload protection. Additional features include low shutdown IQ, programmable soft start, precision reference, a power-good indicator, and external clock synchronization.