SGMICRO Power Management ICs

Choose a DC-DC converter when: 1) There is a large voltage difference between input and output (step-down or step-up)

2) High efficiency is critical, especially for battery-powered devices

3) Heat dissipation is a concern

4) The application can tolerate some output ripple. Choose an LDO when: 1) The input-output voltage difference is small (less than 1V)

2) Low noise and ripple-free output are required for sensitive analog circuits

3) Simplicity and low cost are priorities

4) Fast transient response is needed. SGMICRO offers both options to optimize your power design.

Evaluate your efficiency requirements and noise sensitivity. Contact our FAE team for power architecture recommendations.

DC-DC converter efficiency is affected by several factors: 1) Load current - efficiency typically peaks at mid-to-high loads and decreases at light loads

2) Input-output voltage ratio - larger differences generally reduce efficiency

3) Switching frequency - higher frequencies improve transient response but increase switching losses

4) Inductor and capacitor selection - component quality affects conduction and switching losses

5) Operating temperature - MOSFET resistance increases with temperature. SGMICRO DC-DC converters are optimized for high efficiency across the operating range with peak efficiencies exceeding 95%.

Select converters based on your typical operating point. Review efficiency curves in datasheets for your specific conditions.

Inductor selection involves balancing size, cost, and performance: 1) Inductance value - typically 1uH to 22uH for SGMICRO converters, with higher values for lower switching frequencies

2) Current rating - select an inductor with saturation current at least 1.3x the maximum load current

3) DCR (DC resistance) - lower DCR reduces conduction losses and improves efficiency

4) Core material - ferrite cores are preferred for high-frequency switching

5) Size - chip inductors save space but may have higher DCR. SGMICRO datasheets provide recommended inductor values and part numbers.

Follow datasheet recommendations for inductor selection. Contact us for specific inductor part number recommendations.

PSRR (Power Supply Rejection Ratio) measures an LDO's ability to reject ripple and noise from the input supply. It is expressed in dB, with higher values indicating better rejection. PSRR is critical for powering noise-sensitive circuits such as RF amplifiers, precision ADCs, and audio circuits. At low frequencies (below 1kHz), PSRR is typically highest (60-80dB). At higher frequencies, PSRR decreases due to parasitic capacitances. For applications requiring very clean supplies, select LDOs with high PSRR and add input/output filtering capacitors.

For noise-sensitive applications, select LDOs with PSRR > 60dB at your frequency of interest. Check PSRR curves in datasheets.

To minimize EMI from DC-DC converters: 1) Use proper PCB layout with short, wide traces for high-current paths

2) Place input capacitors close to the IC to minimize input ripple

3) Use shielded inductors for radiated EMI reduction

4) Implement proper ground planes and minimize loop areas

5) Add snubber circuits if needed for high-frequency ringing

6) Select appropriate switching frequency to avoid sensitive frequency bands

7) Use spread-spectrum modulation if available. SGMICRO converters are designed with EMI considerations and include features to simplify compliance.

Follow layout guidelines in datasheets. For EMI-critical applications, consider pre-compliance testing during design.