MP1584EN-C319-LF-Z

MP1584-C319–3A, 1.5MHz, 36V Buck Converter

high frequency operation

The switching frequency of the MP1584-C319 CAN can be programmed up to 1.5 MHz with an external resistor.

At higher switching frequencies, the inductive capacitor reactance (xl) dominates, allowing the ESL of the input/output capacitors to determine the higher switching frequencies for the input/output ripple voltage. Therefore, high frequency ceramic capacitors are strongly recommended as input decoupling capacitors as well as output filter capacitors for high frequency operation. When devices switch at a higher frequency. It is necessary to input decoupling capacitors, capture diodes and MP1584-C319 (VIN pin, SW pin and PGND) as close as possible, with very short traces and relatively wide. This helps to greatly reduce sw node voltage spikes, as does EMI noise levels. Try running feedback tracking as far away from inductive and noisy power tracking as possible. It's usually a good idea to run feedback tracking with a ground plane on the PCB opposite the inductor to separate the two. This should place the compensation components close to the MP1584-C319. Do not place compensation components close to or below high dv/dt sw nodes, or high di/dt inner power loops. If you must do this, proper ground planes must be isolated in place. Switching losses are expected to be high at the switching frequency. To help improve heat transfer, a grid of thermal vias can be created under the exposed pad. It recommends that they be small (15ml barrel diameter) so that the holes are basically filled during the plating process, thus helping conduction to the other side. Holes that are too large may be in the reflow soldering process. The pitch (distance between a few hot centers) is typically 40mm for an area of vias.

External Bootstrap Diode It is recommended that an external bootstrap diode should be added when the input voltage is NO. rails greater than 5 volts or 5 volts are available in the system. This helps improve the regulator. The bootstrap diode may be very low cost as 4148 or BAT44.

This diode is also recommended for high duty cycle operation (VOUT/VIN>65%) or low VIN (<5VIN) applications.

At no load or light load, the converter can operate in pulse skipping mode to maintain regulation of the output voltage. therefore

Less time to refresh the BS voltage. In order to have adequate gate voltage operating conditions in this case, the VIN–VOUT difference should be greater than 3V. For example, if VOUT is set to 3.3V, VIN needs to be higher than 3.3V+3V=6.3V to maintain sufficient BS voltage at no load or light load. To meet this requirement, the en-pin can be used to program the input uvlo voltage to vout+3V.