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

The LM5158x -Q1 device is a wide input range, non-synchronous boost converter with an integrated 85-V, 3.26-A (LM5158 -Q1) or 85-V, 1.63-A (LM51581 -Q1) 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) for automotive load dump. 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.