Conditions — 1 MHz; 1.0 V (RMS not stated); 25 °C ambient.
Why it matters — Sets the starting inductance used in ripple and control calculations. This small-signal value is not the inductance guaranteed at operating bias.
MST ENGINEERING · READ / COMPARE / VERIFY
VCMA-0420-R22-M-1A datasheet explained
A3 added MAX current columns; A4 added the voltage column. Read nominal inductance, bias limits, heating limits and mounting drawings separately. The MAX current-column convention remains unresolved.
AI-assisted technical interpretation, checked against the cited PDFs. Application replacement has not been tested.
01 / PARAMETERS & CONDITIONS
What each specification actually says
Typ, min and max retain the document’s labels. A dash means no value is stated for that label; it does not mean zero.
Electrical ratings 5
Conditions — Table note: 25 °C ambient. Instrument is not stated for DCR.
Why it matters — Supports a DC conduction-loss budget. Use the stated maximum for a bound at its reference temperature; it excludes AC/core loss.
Conditions — Approximately +40 °C rise from 25 °C ambient; DC test current.
Why it matters — Describes self-heating under the supplier test method. Verify total temperature on the actual PCB and current waveform.
The printed MAX value is 10.0 A, below TYP 12.0 A. No reinterpretation as MIN or absolute maximum is made.
Conditions — DC current at approximately 30% L0 decrease; 25 °C ambient.
Why it matters — Marks a stated inductance-drop threshold. It is neither a continuous-current rating nor a no-saturation boundary.
The MAX-column value 17.5 A is retained literally; no guaranteed hot-current limit is inferred.
Conditions — A4 adds the MAX voltage column. Surge, dielectric and waveform test details are not supplied.
Why it matters — Check the actual component voltage stress and its transients against the confirmed rating.
Temperature limits 2
Conditions — Ambient plus self-heating.
Why it matters — A material operating/storage limit, distinct from ambient temperature and from a permitted temperature rise.
Conditions — Not specified for this field in the cited pages.
Why it matters — A material operating/storage limit, distinct from ambient temperature and from a permitted temperature rise.
Construction 1
Construction and declarations
magnetically shielded; AEC-Q200 qualified; RoHS compliant; halogen free declaration
PDF p. 2Conditions — Not specified for this field in the cited pages.
Why it matters — A declaration in this document. It does not qualify the finished equipment or replace a product-specific qualification report.
Core chemistry and an individual qualification report are not included.
Dimensions and PCB lands 4
Body outline
x: 4.4 ±0.35; y: 4.2 ±0.25; height: 1.8 ±0.2; maximum envelope: 4.75; 4.45; 2 mm
PDF p. 2, 4Conditions — Not specified for this field in the cited pages.
Why it matters — Use with the original drawing for clearance, terminal overlap and assembly review. A body size does not establish PCB compatibility.
Terminal drawing callouts
horizontal terminal callout: 0.8 ±0.3; terminal width: 2.0 ±0.3; coplanarity or standoff callout: 0 to 0.15 mm
PDF p. 4Conditions — Not specified for this field in the cited pages.
Why it matters — Use with the original drawing for clearance, terminal overlap and assembly review. A body size does not establish PCB compatibility.
Keep the drawing orientation; do not substitute these terminal dimensions for the recommended lands.
Recommended PCB lands
pad width: 2.5; pad length along connection axis: 1.5; inner gap: 2.2; outer span: 5.2 mm
PDF p. 4Conditions — Not specified for this field in the cited pages.
Why it matters — A recommended PCB land geometry. Compare copper, mask and paste against both drawings before any replacement.
1.5 mm pad length is calculated as (5.2−2.2)/2; no land tolerance is printed.
Marking convention
Three-digit inductance code; the page illustrates 1R0, not the selected R22 sample. code
PDF p. 4Conditions — Not specified for this field in the cited pages.
Why it matters — Supports part identification together with full reel/lot labels. A generic drawing is not a photograph of this exact model.
Assembly and reflow 6
Conditions — Not specified for this field in the cited pages.
Why it matters — Use to review the permitted assembly thermal profile. Confirm the applicable package classification and line process; this is not an oven recipe or a completed test.
Reflow preheat / soak
SnPb temperature: 100; 150; Pb free temperature: 150; 200; both time: 60; 120 °C; s
PDF p. 8Conditions — Not specified for this field in the cited pages.
Why it matters — Use to review the permitted assembly thermal profile. Confirm the applicable package classification and line process; this is not an oven recipe or a completed test.
Conditions — Average ramp-up from Tsmax to Tp: 3 °C/s maximum; average ramp-down from Tp to Tsmax: 6 °C/s maximum. The limits apply to both solder process columns.
Why it matters — Use to review the permitted assembly thermal profile. Confirm the applicable package classification and line process; this is not an oven recipe or a completed test.
Conditions — Not specified for this field in the cited pages.
Why it matters — Use to review the permitted assembly thermal profile. Confirm the applicable package classification and line process; this is not an oven recipe or a completed test.
Near-peak and total time
within 5C of Tc SnPb: 20; within 5C of Tc Pb free: 30; 25C to peak SnPb max minutes: 6; 25C to peak Pb free max minutes: 8 s; min
PDF p. 8Conditions — Peak temperature/time tolerance is defined by the sheet as supplier minimum and user maximum.
Why it matters — Use to review the permitted assembly thermal profile. Confirm the applicable package classification and line process; this is not an oven recipe or a completed test.
Pb-free peak classification matrix
volume columns mm3: <350; 350–2000; >2000; thickness rows mm: <1.6: 260; 260; 260; 1.6–2.5: 260; 250; 245; >2.5: 250; 245; 245 °C
PDF p. 8Conditions — Generic thickness/volume classification; applicability must be confirmed.
Why it matters — Use to review the permitted assembly thermal profile. Confirm the applicable package classification and line process; this is not an oven recipe or a completed test.
No inferred SnPb correction: that table repeats a volume heading. No standalone guaranteed part-specific peak is asserted here.
Packaging 6
Conditions — Not specified for this field in the cited pages.
Why it matters — For reel/feed and assembly preparation; it is not an inventory or order-quantity promise.
Carrier tape and sprocket geometry
tape width: 12 ±0.3; pocket pitch: 8 ±0.1; sprocket pitch: 4 ±0.1; hole diameter: 1.5 ±0.1; half pitch: 2 ±0.1; edge to hole: 1.75 (no tolerance printed); hole line to pocket center: 5.5 ±0.1 mm
PDF p. 9Conditions — Not specified for this field in the cited pages.
Why it matters — For reel/feed and assembly preparation; it is not an inventory or order-quantity promise.
Conditions — Not specified for this field in the cited pages.
Why it matters — For reel/feed and assembly preparation; it is not an inventory or order-quantity promise.
Reel geometry
outer diameter: 330 ±2.0; hub diameter: 100 ±1.0; center hole: 13.0 ±1.0; surrounding hole callout: 20.0 ±0.5; key callout: 2.0 ±0.5; A: 12.5 ±0.5; B: 2.0 ±0.2 mm
PDF p. 10Conditions — Not specified for this field in the cited pages.
Why it matters — For reel/feed and assembly preparation; it is not an inventory or order-quantity promise.
Conditions — Not specified for this field in the cited pages.
Why it matters — For reel/feed and assembly preparation; it is not an inventory or order-quantity promise.
Cover-tape peel
force: 0.1; 1.3; peel speed approx: 300; peel angle: 165; 180 N; mm/min; degrees
PDF p. 10Conditions — Not specified for this field in the cited pages.
Why it matters — For reel/feed and assembly preparation; it is not an inventory or order-quantity promise.
Curves and document coverage
L and temperature rise versus DC bias: VCMA-0420-R22-M-1A
26 ±3 °C; RH <70%; 1 MHz, 1.0 V; Wayne Kerr 3260B/G + 3265B.
Curves were visually located, not digitized or treated as guaranteed limits. The page-3 table controls the quoted rating.
PDF p. 5- Revision history · p. 1
- Series identity/environment · p. 2
- Selected electrical row and all five notes · p. 3
- Outline, lands, marking · p. 4
- Selected R22 curves and conditions · p. 5
- Other model curves · p. 6, 7
- Reflow chart and tables · p. 8
- Tape, reel, peel, quantities · p. 9, 10
Still needs confirmation
- Meaning and acceptance convention of the current MAX columns; manufacturer-guaranteed hot L/current bounds.
- Core/AC loss model, SRF, Q, magnetic material, MSL, voltage transient/dielectric conditions and process-specific qualification report are not supplied in the cited sheet.
- MAZO A4 is a manufacturer-branded public MST mirror; latest factory release and lot applicability are unconfirmed.
Compare this model
Can VCMA-0420-R22-M-1A replace XAL4020-221MEC? Read the current and pad conditions first →
03 / ENGINEERING DISCUSSION
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