TPS5430DDAR vs LM2597MX-5.0/NOPB vs LM5163QDDARQ1: Which Buck Regulator Fits the Design?

Quick answer: TPS5430DDAR, LM2597MX-5.0/NOPB and LM5163QDDARQ1 address different power-supply requirements. Evaluate TPS5430DDAR for loads above 0.5 A and up to its 3 A rating, provided the complete input, output and thermal requirements are met. Evaluate LM2597MX-5.0/NOPB for an existing fixed 5 V, low-current design that uses its supervisory functions. Evaluate LM5163QDDARQ1 for a high-input-voltage, low-current rail or an application requiring its automotive qualification. None is a drop-in replacement for the other two.

The useful comparison is the complete power rail: input extremes, output load, startup, external components, PCB and approval requirements. A shared eight-pin description is not enough to release a BOM change. The scenarios below are illustrative engineering screens, not customer case studies or tested reference designs.

1. Compare the design limits first

This table separates exact-device facts from selection judgments. The numbered sources below link to TI documents; where a family datasheet covers several variants, the values here apply to the named ordering code.

On a narrow screen, scroll the table horizontally.

The LM2597 input-range trap: its fixed 5 V output is specified under 7–40 V input and 0.1–0.5 A load conditions in the datasheet electrical-characteristics table. The 4.5 V family operating minimum does not mean a buck regulator can maintain 5 V output from 4.5 V input. Nor should 7 V be treated as a universal startup threshold.

Ranges are not simultaneous guarantees: a maximum input voltage, maximum output voltage and maximum load cannot simply be combined into a validated operating point. Check the applicable duty-cycle, timing, current and temperature limits in the chosen datasheet.

2. Keep the complete ordering code in the BOM

Match the exact TI orderable-part page, package drawing and assembly requirements. Suffixes are not a universal decoding system across different TI product families.

TI listed all three exact codes as ACTIVE when checked on 5 September 2026; see orderable-part sources [7]–[9]. That status and the nominal reel quantity do not establish any seller's current stock, price, minimum order or delivery date.

3. Use this selection sequence

1. Define the input envelope. Record minimum, nominal and maximum continuous voltage, plus the transient voltage actually reaching the IC after input protection. A nominal bus name alone leaves too much unspecified.
2. Screen the load. Record steady-state demand, startup charging and load steps. For initial selection, treat LM2597 and LM5163-Q1 as 0.5 A-class devices; requirements above 0.5 A call for a higher-current candidate and a fresh operating-point review. If the required continuous output exceeds 3 A, expand the search beyond all three.
3. Define the output. Confirm voltage, tolerance, ripple, sequencing and brownout behavior. An existing fixed-output circuit and an adjustable-output circuit require different feedback reviews.
4. Check system interfaces and qualification. Identify every connected control or status pin. Decide whether the project requires automotive qualification, specific temperature performance or additional system-level evidence.
5. Estimate the redesign and validation work. Review the complete schematic, layout and component network before comparing commercial offers. For an existing assembly, record both the technical change and the approval route.

If no candidate passes every hard requirement, the correct result is a wider component search. Selecting the closest headline specification is not a substitute for meeting the design envelope.

4. Three practical design scenarios

Scenario A: a nominal 24 V input and a 5 V, 2 A rail

TPS5430DDAR is the current-capable candidate in this comparison. The other two are 0.5 A parts and fail the 2 A requirement before price or board area enters the decision. Check the true input maximum, not just the 24 V label, and account for cable transients and the chosen protection network.

The illustrative output power is 5 V × 2 A = 10 W; this is a requirement calculation, not an efficiency or thermal measurement. Establish losses, diode dissipation, inductor peak current, capacitor behavior and pad-to-board heat flow for the actual PCB. A 3 A IC rating does not prove that a particular enclosure and layout can continuously deliver it.

Scenario B: maintaining an existing fixed 5 V, 0.3 A control rail

LM2597MX-5.0/NOPB deserves an exact-part review when the original schematic uses its Error Flag, Delay, Bias Supply or Shutdown/Soft-Start functions. Start by tracing those connections to the rest of the system. A rail that reaches the correct final voltage can still fail the product if the controller receives an incorrect reset or fault sequence.

Confirm input headroom and the specified load conditions, then evaluate the existing capacitor and diode network, especially if component substitutions or aging have changed it. Keeping a known design can reduce the scope of requalification, but it is not evidence that every old BOM line remains acceptable. If changing the regulator, budget the interface redesign as well as the power-stage redesign.

Scenario C: a nominal 48 V input and a low-current auxiliary rail

LM5163QDDARQ1 is the high-input-voltage candidate here, provided the required load stays within its capability. A 48 V nominal bus is already above the TPS5430 recommended maximum and the non-HV LM2597 range. Do not borrow the LM2597HV rating for the LM2597MX code in this article.

The higher input rating still requires a transient budget, input protection, suitable capacitors, layout and thermal verification. For battery-connected systems, measure complete-board standby current in the intended state. Feedback dividers, pullups and other connected loads can matter alongside the regulator itself.

TI's 10.5 µA typical LM5163-Q1 sleep-current figure is specified under particular conditions: VIN = 24 V, TJ = 25°C, VEN = 2.5 V and VFB = 1.5 V in the electrical table. It is not a universal board-consumption figure. The grade-1 ambient range is −40°C to +125°C; the junction range is −40°C to +150°C. Keep ambient and junction temperature separate when evaluating an automotive requirement.

5. Why the same pin count does not mean compatibility

The pin tables provide a concrete reason to reject an unreviewed swap. Even the two DDA devices assign different functions to the same pin numbers.

Moving an IC onto a superficially similar footprint could therefore connect a board net to an unrelated function. Compare every pin, exposed pad, land pattern and package dimension against the schematic. A carrier change within one approved device is a different question from exchanging devices with different pin functions.

6. Treat a regulator change as a power-rail change

Use the chosen regulator's application guidance to select components; copying a previous inductor or capacitor value does not validate the new circuit. An internal compensation feature does not remove the need to check the allowed external network and operating range.

For the handoff between engineering and purchasing, our BOM sourcing and approval playbook for OEM and EMS teams provides the broader RFQ-to-release workflow.

7. Turn the technical decision into an actionable RFQ

Quote the exact part and any proposed alternate on separate lines. The supplier should be able to see whether the request concerns an approved replacement purchase or an engineering evaluation. A useful starting template is:

Required exact MPN:
Approved manufacturer and AVL status:
Quantity, prototype or production, and packing:
Input minimum / nominal / maximum / protected transient:
Output voltage / continuous load / startup and load steps:
Temperature, qualification and control/status-pin requirements:
Traceability, lot/date and inspection requirements:
Delivery destination and required date:
Alternates: prohibited / separate engineering proposal only
Required approval owner and validation evidence:

Use the component quotation comparison checklist to align commercial terms after the technical requirement is fixed. For lot evidence and source-chain questions, consult the component traceability buyer checklist.

The corresponding store enquiry pages are TPS5430DDAR, LM2597MX-5.0/NOPB and LM5163QDDARQ1. Use the TI references below for design specifications and confirm availability, documentation and delivery terms for the particular quote. For a multi-line requirement, see our BOM sourcing services.

8. Frequently asked questions

Which of these regulators can support a 2 A output requirement?

TPS5430DDAR is the only candidate in this set with a sufficient headline current rating. The actual operating point still needs component, thermal and transient verification.

Is LM2597MX-5.0/NOPB an adjustable regulator?

No. This exact ordering code is the fixed 5 V version. Do not transfer specifications or feedback arrangements from an adjustable LM2597 variant without checking the exact device.

Can LM5163QDDARQ1 replace TPS5430DDAR on the same PCB?

It is not a pin-compatible substitution. The pin assignments, current capability, control and external network differ. Treat it as a redesign proposal that needs a schematic review and validation.

Does the LM5163-Q1 automotive rating certify my complete power supply?

No. Component qualification is one input to system approval. The application still needs its own electrical, environmental and other applicable validation; it is not automatically certified by the device selection.

Can any of the three be selected for a 48 V bus?

Only LM5163QDDARQ1 has a stated input range covering 48 V in this comparison. Suitability also depends on the protected transient envelope, output requirement and full circuit design.

Which part is cheapest or available now?

This article does not provide a live inventory or price comparison. Request current, part-specific offers after fixing the technical requirement; compare the complete change cost when a redesign is involved.

9. TI sources and verification scope

Technical and orderable-part sources were checked on 5 September 2026. The decision sequence, illustrative scenarios and procurement checklist are editorial synthesis; the underlying electrical and packaging facts come from TI. Recheck the current revision when releasing a design or purchase.

1. TPS543x datasheet, Rev. L — recommended conditions, pin functions, switching behavior and application guidance.
2. LM2597 / LM2597HV datasheet, Rev. D — exact non-HV and fixed 5 V conditions, pins and external circuit requirements.
3. LM5163-Q1 datasheet, Rev. A — pin functions, current and frequency limits, sleep-current test conditions and qualification.
4. TPS5430 product page — family parameters and design resources.
5. LM2597 product page — family parameters; distinguish non-HV and HV variants.
6. LM5163-Q1 product page — output parameter range and automotive product information.
7. TPS5430DDAR exact orderable-part page — status, package, grade and carrier.
8. LM2597MX-5.0/NOPB exact orderable-part page — status and exact packaging attributes.
9. LM5163QDDARQ1 exact orderable-part page — status, automotive grade and carrier.