E1M-X V2N Reliability Report (MTBF)
Summary
This report gives the predicted reliability of the E1M-X V2N System-on-Module (Renesas RZ/V2N, base variant — no on-module DeepX accelerator) as MTBF and FIT (1 FIT = 1 failure per 109 device-hours). It is a parts-count prediction per Telcordia SR-332 Issue 4, summing the steady-state failure rate of the module's electrical components. It is an intrinsic, random-failure estimate for the useful-life region; it excludes infant mortality and end-of-life wear-out.
Headline — at the +55 °C operating reference (GF): λ ≈ 2443 FIT, giving an MTBF of ≈ 409 000 hours, equivalent to a 5-year field survival of ≈ 89.9% and a 10-year survival of ≈ 80.7% under continuous 24/7 use. See Results and the +25…+85 °C sweep in Temperature & Environment Sensitivity.
MTBF is a fleet statistical measure, not a service life. 409 000 h does not mean a unit lasts 47 years; it means one intrinsic failure is expected per 409 000 cumulative operating hours across a fielded population — i.e. ≈ 102 failures per 1000 units over 5 years of 24/7 use. The figure reflects this module's high complexity (≈1180 parts, dual-PHY, multi-rail power, large memory).
This report covers the base V2N. The V2N-M1 variant (DeepX DX-M1 populated) is covered by RL-V2NM1-001 and predicts ≈ 2842 FIT / ≈ 352 000 h at +55 °C — the DeepX accelerator and its dedicated LPDDR4X + PCIe-mux subsystem add ≈ 122 FIT.
Reference Condition
Table: Reference condition for the headline prediction
| Parameter | Value |
|---|---|
| Prediction standard | Telcordia SR-332 Issue 4, Method I (parts count) |
| Environment | Ground Fixed, Controlled (GF) |
| Rated operating range | − 40 °C to +85 °C (industrial extended) |
| Headline operating ambient | +55 °C (representative loaded operating point) |
| Component-FIT build-up | +40 °C (Telcordia generic-device reference) |
| Duty cycle | 100% (continuous, 24/7) |
| Component quality | Commercial, Quality Level II |
| Confidence level | 50% (point estimate) |
Method
The module failure rate is the series sum λmodule = Σi ni · λi (any one part failing is a module failure; no on-module redundancy), and MTBF = 1 / λmodule. The per-class FIT is tabulated at the +40 °C Telcordia reference (build-up ≈ 1087 FIT) and scaled to the +55 °C operating headline by πT ≈ 2.25 on the silicon subtotal (Temperature & Environment Sensitivity), giving ≈ 2443 FIT.
Failure-Rate Budget
The base module carries ≈ 1180 electrical placements. Silicon is ≈ 55% of the budget; the Renesas SoC is ≈ 11%. Values at the +40 °C Telcordia reference build-up.
Table: E1M-X V2N failure-rate budget by class (+40 °C Telcordia reference)
| Component class | Qty | FIT total | Share |
|---|---|---|---|
| Ceramic capacitors (MLCC) | 810 | 324.4 | 29.8% |
| Application SoC (Renesas RZ/V2N) † | 1 | 120.0 | 11.0% |
| DC-DC switching regulators | 5 | 76.0 | 7.0% |
| Wi-Fi / BLE module (Murata) † | 1 | 60.0 | 5.5% |
| Flash — eMMC / OSPI NOR / SPI NAND § | 3 | 56.2 | 5.2% |
| Chip resistors | 370 | 55.5 | 5.1% |
| Load switches | 10 | 50.0 | 4.6% |
| Crystals | 6 | 48.0 | 4.4% |
| Ethernet PHY (2 × GbE) | 2 | 40.0 | 3.7% |
| LDO regulators | 6 | 36.0 | 3.3% |
| Clocks / RTC | 4 | 36.0 | 3.3% |
| Multi-output PMIC | 1 | 25.0 | 2.3% |
| LPDDR4 DRAM (main) § | 1 | 20.0 | 1.8% |
| CAN transceivers | 2 | 20.0 | 1.8% |
| Ferrite beads | 38 | 19.0 | 1.7% |
| Power inductors | 19 | 19.0 | 1.7% |
| Board-to-board connector | 1 | 15.0 | 1.4% |
| Companion MCU (GD32) | 1 | 15.0 | 1.4% |
| EEPROM | 2 | 12.0 | 1.1% |
| Secure element | 1 | 7.0 | 0.6% |
| Other (level shifter, LED drv, temp, buffer, TVS, supercap, RF conn) | 9 | 32.5 | 3.0% |
| Total | ∼ 1180 | ≈ 1087 | 100% |
† engineering estimate pending vendor reliability report (Renesas SoC, Murata Wi-Fi module). § chi-square 60% upper confidence limit from the JEDEC JESD47 HTOL qualification, accelerated to +40 °C with Ea = 0.7 eV (memory). The DeepX accelerator and its dedicated LPDDR4X / PCIe muxes are not fitted on the base V2N. Shares may not sum to 100% due to rounding.
Results
Table: Predicted reliability at the +55 °C operating headline (GF)
| Metric | Value |
|---|---|
| Total failure rate, λ | 2443 FIT |
| MTBF | 409 000 h |
| MTBF (years, continuous) | 47 yr |
| Survival R(1 yr) | 97.88% |
| Survival R(3 yr) | 93.78% |
| Survival R(5 yr) | 89.85% |
| Survival R(10 yr) | 80.74% |
Table: Expected intrinsic failures per 1000 fielded units (24/7, +55 °C)
| Mission time | Survival R(t) | Fails / 1000 units |
|---|---|---|
| 1 year | 97.88% | ≈ 21.2 |
| 3 years | 93.78% | ≈ 62.2 |
| 5 years | 89.85% | ≈ 101.5 |
| 10 years | 80.74% | ≈ 192.6 |
Temperature & Environment Sensitivity
The silicon subtotal scales by πT = exp[Ea/k (1/Tref − 1/T)] with a generic Ea = 0.7 eV; passives, crystals, connectors and the PCB are held roughly constant. Each row assumes junctions track ambient; under heavy load the junctions self-heat above ambient, so the hot-corner rows are ambient-only and optimistic until the thermal solution is folded in.
Table: MTBF vs. ambient temperature (junction ≈ ambient)
| Ambient | πT | λ (FIT) | MTBF (h) | MTBF (yr) | R(5 yr) |
|---|---|---|---|---|---|
| +25 °C | 0.27 | 652 | 1 534 000 | 175 | 97.2% |
| +40 °C † | 1.00 | 1087 | 920 000 | 105 | 95.4% |
| +55 °C * | 3.27 | 2443 | 409 000 | 47 | 89.9% |
| +70 °C | 9.66 | 6249 | 160 000 | 18 | 76.0% |
| +85 °C ‡ | 26.0 | 15 006 | 66 600 | 8 | 51.7% |
* Headline operating point. † +40 °C Telcordia build-up reference. ‡ Rated maximum ambient.
The Renesas SoC and the multi-rail power section are the hottest parts and dominate the temperature sensitivity — thermal design there is the highest-leverage reliability action for the integrator.
Assumptions & Limitations
- Parts-count (Method I), not parts-stress — accepted at the design/datasheet stage and typically conservative for a derated design.
- Series reliability — no on-module redundancy credited.
- Mixed FIT provenance. Renesas SoC and the Murata Wi-Fi module (†) are engineering estimates pending vendor data; memory FITs (§) are conservative JEDEC-qual chi-square bounds.
- Base variant — the DeepX subsystem is excluded; see RL-V2NM1-001 for the M1.
- Excludes solder-joint thermal fatigue, infant mortality, end-of-life wear-out.
- Point estimate at 50% confidence.
Revision History
Table: Document revision history
| Revision | Changes | Date |
|---|---|---|
| 0.1 | Initial parts-count MTBF prediction (Telcordia SR-332 Issue 4) from the released E1M-X V2N netlist (base variant, DeepX subsystem excluded). Renesas SoC and Wi-Fi module on engineering estimates; memory on JEDEC-qual chi-square bounds. | June 2026 |