MST ENGINEERING · READ / COMPARE / VERIFY
LPCA-1040-R36-M versus SRP1038A-R36M: why 50 A and 60 A do not mean the same thing
No interchangeability conclusion follows from those matches. Bourns lists 60 A at 20% inductance reduction; MAZO lists 50 A typical at 30% reduction. MAZO’s separate heating-current figure is 30 A, not 50 A continuous. Recommended pad widths, inductance-test frequency and total-temperature limits also differ.
AI-assisted technical interpretation, checked against the cited PDFs. Application replacement has not been tested.
MST TECHNICAL EDITORIAL
Read the source interpretation first
Bourns manufacturer-hosted SRP1038A PDF and manufacturer-branded MAZO A1 PDF mirrored by MST. No manufacturer cross-reference or test certificate establishing this substitution was found in the reviewed sources.
Compare the published specifications
| Parameter | SRP1038A-R36M | LPCA-1040-R36-M | Engineering meaning |
|---|---|---|---|
| L0 and measurement | 0.36 µH 100 kHz; 1 V; electrical specifications at 25 °C. PDF p. 1 | 0.36 µH A1: 1 MHz, 1 V; 25 °C ambient; RMS notation absent. PDF p. 3 | 0.36 µH / ±20% on both sheets, measured at 100 kHz versus 1 MHz. Keep the source revision: the older MAZO mirror had 100 kHz. |
| DC resistance | typ: 1.05; max: 1.2 mΩ 25 °C electrical specifications. PDF p. 1 | typ: 1.05; max: 1.2 mΩ 25 °C ambient reference. PDF p. 3 | Both list 1.05 mΩ typical and 1.2 mΩ maximum at the 25 °C electrical reference. This does not establish equal switching loss. |
| Isat criterion | 60 A 20% inductance drop; electrical specifications at 25 °C. PDF p. 1 | 50 A DC current; approximately 30% L0 decrease; 25 °C ambient. PDF p. 3 | 60 A / 20% versus 50 A TYP / 30%. No common-threshold conversion is possible from these two headline values alone. |
| Heating-current criterion | 31 A +40 °C temperature rise; electrical specifications at 25 °C. PDF p. 1 | 30 A DC current; approximately +40 °C rise at 25 °C ambient. PDF p. 3 | 31 A versus 30 A TYP at +40 °C rise. Similar figures do not prove equal temperature on a common board. |
| Total operating temperature | -55; 150 °C Includes temperature rise. PDF p. 1 | -55; 125 °C Ambient plus self-heating. PDF p. 2, 3 | Bourns allows a stated total range up to +150 °C; MAZO up to +125 °C. A hot design near 150 °C is not covered by the MAZO range. |
| Toleranced body | x: 11.0 ±0.5; y: 10.0 ±0.3; height: 3.8 ±0.2; maximum envelope derived: 11.5; 10.3; 4 mm Not specified for this field in the cited pages. PDF p. 1 | x max: 11.5; y: 10.0 ±0.3; height: 3.8 ±0.2; maximum envelope: 11.5; 10.3; 4 mm Not specified for this field in the cited pages. PDF p. 2, 4 | The maximum envelopes are both 11.5 × 10.3 × 4.0 mm, but this is a clearance comparison only. |
| Recommended lands | pad width: 3.5; pad length along connection axis derived: 4.1; inner gap: 5.4; outer span: 13.6 mm Not specified for this field in the cited pages. PDF p. 1 | pad width: 4.1; pad length along connection axis: 4.1; inner gap: 5.4; outer span: 13.6 mm Not specified for this field in the cited pages. PDF p. 4 | Both have 13.6 mm outer span and 5.4 mm inner gap, while transverse pad width is 3.5 versus 4.1 mm: a 0.6 mm difference. Identical pitch is not identical copper. |
| Declared qualification | shielded; AEC-Q200 compliant; RoHS compliant; halogen free declaration Not specified for this field in the cited pages. PDF p. 1 | magnetically shielded; RoHS compliant; halogen free declaration Not specified for this field in the cited pages. PDF p. 2 | Bourns declares AEC-Q200 compliance. This MAZO LPCA A1 sheet does not. Do not inherit an automotive claim from the VCMA family. |
What this comparison cannot confirm
A datasheet-screened candidate requiring further evidence. Do not approve as a drop-in or label its 50 A Isat as continuous load current.
- A common 20% or 30% Isat curve at hot temperature, voltage/surge capability, common-board loss and EMI performance.
- Application-specific pad acceptance and automotive qualification for LPCA-1040-R36-M.
Application review and proposed tests
Proposed checklist only; no test was performed for this editorial.
- Keep SRP1038A-R36M distinct from SRP1038AA-R36M and use the selected MAZO A1 revision.
- Establish minimum inductance at actual hot peak current, total temperature within the candidate limit, acceptable soldering/lands and any required qualification before release.
- Record the full part numbers, sample lot IDs, PDF revisions, board revision and equipment configuration. Verify markings against reel labels.
- Set application limits first: input/output ranges, switching frequency, phase count, worst-case RMS/peak current, ambient temperature and allowable hot inductance.
- Overlay both mechanical drawings on the actual copper/mask/paste pattern; inspect clearances, solder coverage and assembly tolerances.
- Measure L and DCR with recorded instrument frequency/amplitude/temperature; sweep DC bias and relevant hot conditions without exceeding agreed test limits.
- On the intended board, compare current waveform, ripple, efficiency and stabilized part temperature across the required load/input/ambient range. Record copper, airflow and neighboring heat sources.
- Check startup, shutdown and specified transient/protection cases, then compare EMI and mechanical/acoustic behavior where the design requires it.
- Attach measured results, sample count, acceptance limits and engineering disposition before changing the evidence status to application-validated.
03 / ENGINEERING DISCUSSION
Contributed application evidence
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