In electronics procurement, power regulators are often specified early and then forgotten—until shortages, EOL notices, or unexpected cost increases appear. Understanding when a design relies on an LDO versus a DC/DC converter, and which part families are commonly used, helps buyers plan sourcing strategies more effectively.
This article focuses on real-world selection logic, supported by representative regulator part numbers that procurement professionals frequently encounter.
Typical LDO Use Cases and Common Part Families
LDO regulators are widely used in low- to mid-power rails, analog subsystems, and auxiliary supplies. From a sourcing perspective, they are attractive due to broad availability and strong second-source potential.
Common LDO part examples frequently seen in BOMs:
TI TPS7A02 / TPS7A05 series – ultra-low noise, industrial-grade
ADI ADP150 / ADP7118 – precision analog and RF-friendly LDOs
Microchip MCP1700 / MCP1825 – cost-effective, high-volume options
ST LD1117 / LD39050 – widely available, multiple package options
Why procurement teams favor LDO-based designs:
Multiple manufacturers offer functionally similar alternatives
Long lifecycle and stable demand across industries
Easier qualification of second sources
Lower dependency on external components
For industrial and commercial products with long lifecycles, LDOs often reduce supply chain volatility.
DC/DC Converters: Efficiency with Added Sourcing Complexity
DC/DC converters are essential in designs where power efficiency, battery life, or thermal constraints are critical. However, they introduce tighter coupling between the regulator IC and passive components.
Common DC/DC converter examples used in production designs:
TI TPS62130 / TPS5430 – industrial buck converters with wide VIN
ADI LTC3621 / LTC3115 – high-efficiency and low-noise switching solutions
MPS MP1584 / MP2145 – compact, cost-sensitive designs
Infineon TLF50201 / TLF35584 – automotive and industrial-grade power
Procurement considerations specific to DC/DC designs:
Inductor availability and qualification are critical
Fewer true drop-in replacements across brands
Lead times may vary significantly by vendor and region
EMI-sensitive designs reduce flexibility for substitution
DC/DC solutions require earlier coordination between engineering and purchasing teams.
Cost and Risk Comparison Using Real Components
From a sourcing standpoint, the total cost impact goes beyond IC pricing.
LDO-based rails typically involve:
One regulator IC (e.g., TPS7A02 or MCP1700)
Minimal passives
Broad distributor stock coverage
DC/DC-based rails often require:
Controller IC (e.g., TPS62130)
Qualified inductor (vendor-specific)
Additional capacitors and EMI considerations
In mid-volume industrial products, buyers frequently find that LDO solutions lower overall procurement risk, even when DC/DC efficiency appears attractive on paper.
Hybrid Architecture: A Procurement-Friendly Compromise
Many modern designs use a hybrid power strategy:
One DC/DC converter generates an intermediate rail
Local LDOs provide clean power to sensitive subsystems
Example structure:
TPS5430 buck for main rail
ADP150 or TPS7A05 LDOs for ADCs, sensors, or RF blocks
This approach limits exposure to specialized switching components while maintaining efficiency where it matters most.
Second-Source Strategy and Part Interchangeability
Procurement teams should proactively ask:
Are alternatives like TPS7A02 ↔ ADP150 pre-approved?
Can multiple inductors support the same DC/DC controller?
Is the design locked to one manufacturer's ecosystem?
LDO designs generally allow faster cross-referencing, while DC/DC solutions benefit from early alternate qualification.
Practical Guidance for Buyers
Before freezing a BOM:
Request a list of approved alternate regulators
Verify distributor stocking depth for key part numbers
Confirm lifecycle status (NRND / EOL risk)
Align power architecture with long-term sourcing strategy
Conclusion
Choosing between an LDO and a DC/DC converter is not just a technical decision—it directly affects sourcing flexibility, cost stability, and supply chain resilience. LDOs such as TPS7A02, ADP150, or MCP1700 offer simplicity and availability, while DC/DC converters like TPS62130 or LTC3621 deliver efficiency at the cost of tighter sourcing constraints.
At Perceptive Components, we support procurement and engineering teams with real-world component insight, cross-referencing support, and supply chain transparency—helping buyers select power solutions that are not only functional, but also sustainable to source.
