7.1 Overview

The LMZM33604 is a full-featured 36-V input, 4-A, synchronous step-down converter with controller, MOSFETs, shielded inductor, and control circuitry integrated into a low-profile, overmolded package. The device integration enables small designs, while providing the ability to adjust key parameters to meet specific design requirements. The LMZM33604 provides an output voltage range of 1 V to 20 V. An external resistor divider is used to adjust the output voltage to the desired value. The switching frequency can also be adjusted, by either an external resistor or a sync signal, which allows the LMZM33604 to optimize efficiency for a wide variety of input and output voltage conditions. The device provides accurate voltage regulation over a wide load range by using a precision internal voltage reference. The EN pin can be pulled low to put the device into standby mode to reduce input quiescent current. The system undervoltage lockout can be adjusted using a resistor divider on the EN pin. A power-good signal is provided to indicate when the output is within its nominal voltage range. Thermal shutdown and current limit features protect the device during an overload condition. A 41-pin, QFN package that includes exposed bottom pads provides a thermally enhanced solution for space-constrained applications.