WIZARD
Procurement Guide

Power IC Selection Guide — LDO vs Buck for Your BOM

Wizard TeamJune 22, 20251 min read

Power IC selection errors cause board failures in the field. This guide helps procurement teams order the right parts the first time.

When to Use an LDO (AMS1117)

  • Low noise requirements (analog rails, RF sections)
  • Small voltage drop (3.7V → 3.3V)
  • Low current (<500mA typical)

Caveat: LDOs waste power as heat. A 5V→3.3V LDO at 500mA dissipates 850mW.

When to Use a Buck Converter (MP1584, TPS5430)

  • Input voltage >> output voltage (12V → 3.3V)
  • Current >500mA
  • Battery-powered devices needing efficiency

Quick Reference

| Part | Type | Max Current | Input Range | |------|------|-------------|-------------| | AMS1117-3.3 | LDO | 1A | 4.75-15V | | MP1584EN | Buck | 1.5A | 4.5-28V | | TPS5430 | Buck | 3A | 5.5-36V |

All three are in stock at Wizard. Submit your power rail requirements via RFQ for bundle pricing.

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