RX-4045NB
Successor: RX4901CE
The RX-4045NB is going end of life. Epson discontinuation notice 25-012E dated 28 October 2025 · last time buy was 16 April 2026 · final shipment end of October 2026 · reason: ageing production line for these packages. What you can design in now, which route is the smaller intervention and what changes in layout and firmware — set side by side here.
RX-4045NB versus RX4901CE
| RX-4045NB — end of life | RX4901CE — successor | |
|---|---|---|
| Status | Discontinued — final shipment October 2026 | Active, series programme |
| Interface | SPI | SPI (3-wire and 4-wire as an ordering option) |
| Package | SON-22 | CE 3.2 × 2.5 × 1.0 mm |
| Footprint area | 31.5 mm² | 8.0 mm² |
| Supply voltage | 1.15 – 5.5 V | 1.6 – 5.5 V · timekeeping down to 1.1 V |
| Timekeeping | Timekeeping from 1.15 V | 1.6 – 5.5 V · timekeeping down to 1.1 V |
| Standby current | 480 nA typ. | 240 nA typ. · 1500 nA max. |
| Accuracy | ±5.0 ppm at +25 °C | ±3.0 ppm over −40 … +85 °C (DTCXO) |
| Temperature range | −40 … +85 °C | −40 … +105 °C |
Function set of the RX-4045NB: the SPI counterpart to the RX-8025: full calendar, alarm, periodic interrupts, oscillation stop detection. Epson product number: on request.
Two ways out of the discontinuation
RX-4045SA
identical series in the SOP package — stays in the programme. Package: SOP-14.
- The register map stays the same — the firmware does not have to be touched
- Electrical figures stay within the range of the series
- Only the footprint on the board changes
RX4901CE
The official successor. Not a drop-in: package, footprint and register map all change. In return you get:
- DTCXO — accuracy across the whole temperature range
- Operation up to +105 °C
- 32 time stamps (FIFO or three channels)
- Self-monitoring
- Automatic switchover to the backup source
- Tolerance grades XS / XB
- Footprint area drops from 31.5 mm² to 8.0 mm²
Frequently asked questions
Is the RX-4045NB discontinued?
Yes. Epson discontinued the type with notice 25-012E dated 28 October 2025. The last order date was 16 April 2026 and the final shipment goes out at the end of October 2026. The reason is the ageing production line for this package.
What is the successor to the RX-4045NB?
Epson recommends the RX4901CE. It is not a drop-in replacement: the package changes to CE 3.2 x 2.5 x 1.0 mm, so the printed circuit board has to change. If you want to avoid that effort, look at the RX-4045SA from the same series first.
Can I replace the RX-4045NB pin-compatibly?
No. Neither the RX4901CE nor the sibling types sit on the same footprint. A layout step is required either way; the smaller intervention is moving within the series to the RX-4045SA, because the register map and therefore the firmware stay the same.
Where can I still get the RX-4045NB?
Timing Devices Europe stocks the Epson RTC programme in Ladenburg near Heidelberg, Germany. Ask for remaining stock, successor samples and migration planning in one go — we answer the same working day.
Remaining stock, samples and successor in one enquiry.
We stock the Epson RTC programme in our own warehouse in Ladenburg near Heidelberg — physically on site, not at the manufacturer. Tell us your annual demand for the RX-4045NB and we will put together remaining coverage and successor samples.