ISL6545

The ISL6545, ISL6545A makes simple work out of implementing a complete control and protection scheme for a DC/DC stepdown converter driving N-Channel MOSFETs in a synchronous buck topology. Since it can work with either 5V or 12V supplies, this one IC can be used in a wide variety of applications within a system. The ISL6545, ISL6545A (hereafter referred to as ISL6545x, except as needed) integrates the control, gate drivers, output adjustment, monitoring and protection functions into a single 8 Ld SOIC or 10 Ld DFN package. The ISL6545x provides single feedback loop, voltage-mode control with fast transient response. The output voltage can be precisely regulated to as low as 0. 6V, with a maximum tolerance of ±1. 0% over-temperature and line voltage variations. A selectable fixed frequency oscillator (ISL6545 for 300kHz; ISL6545A for 600kHz) reduces design complexity, while balancing typical application cost and efficiency. The error amplifier features a 20MHz gain-bandwidth product and 9V/µs slew rate which enables high converter bandwidth for fast transient performance. The resulting PWM duty cycles range from 0% to 100%. Protection from overcurrent conditions is provided by monitoring the r_DS(ON) of the lower MOSFET to inhibit PWM operation appropriately. This approach simplifies the implementation and improves efficiency by eliminating the need for a current sense resistor.