DS3231M
Epson alternative: RX8900CE

MEMS resonator against a quartz DTCXO

The DS3231M is the MEMS variant of the DS3231 — smaller and cheaper, but noticeably less accurate. If you are looking at it as a replacement or a second source, this is where it stands against the closest Epson type.

The DS3231M does not use a quartz crystal. Its time base is a microelectromechanical resonator, which is what makes the smaller package possible.

DS3231M versus RX8900CE

DS3231M — Analog DevicesRX8900CE — Epson
ManufacturerAnalog Devices (formerly Maxim)Epson (Seiko Epson)
StatusActive series typeActive series type
InterfaceI²C (400 kHz)I²C (400 kHz)
Time baseMEMS resonator, integratedquartz crystal, integrated, DTCXO
Accuracy±5 ppm from −45 to +85 °C±3.4 ppm across −40 to +85 °C (DTCXO)
Timekeeping current2 – 3.0 µA typ. · 3.5 µA max.700 nA typ. · 1.4 µA max.
Supply2.3 – 5.5 V (VCC and VBAT)2.5 – 5.5 V · clock from 1.6 V
Max. temperature+85 °C−40 … +85 °C
PackageSO-8 or SO-16CE 3.2 × 2.5 × 1.0 mm · 8.0 mm² footprint
Extrastwo alarms, square-wave outputbackup switching, oscillator stop detection

What speaks for and against the change

We sell Epson — and we still say where the competitor is better. You would notice it at the first datasheet comparison anyway.

Where the DS3231M is ahead

Honestly

  • The SO-8 version is the more compact of the two Maxim options and easy to hand-solder
  • A MEMS resonator is mechanically robust and insensitive to shock
  • Same register map as the DS3231, so an existing driver carries over
Where Epson wins

The difference

  • Accuracy: ±3.4 ppm against ±5 ppm — Epson is the tighter part across the industrial range
  • Current: 700 nA typical against 2 to 3 µA, and 1.4 µA against 3.5 µA in the worst case
  • Board area: 8.0 mm² against an SO-8 or SO-16
  • A DTCXO with a real quartz crystal ages more predictably than a MEMS time base — worth weighing where the product has to hold time for years
Not a drop-in: package, pinout and register map differ between manufacturers. Budget for a layout change and a driver adaptation — we will supply the documents for both sides.

Frequently asked questions

What is the Epson alternative to the DS3231M?

The RX8900CE is the closest match, with the RX8901CE where you need it tighter still. Both carry a factory-calibrated quartz crystal with digital temperature compensation and are specified more tightly than the DS3231M across the industrial range.

How accurate is the DS3231M?

The datasheet specifies ±5 ppm from −45 to +85 °C, which is about 0.43 seconds per day. Epson's RX8900CE is at ±3.4 ppm and the RX8901CE at ±3.0 ppm across −40 to +85 °C.

What is the difference between the DS3231 and the DS3231M?

The DS3231 uses a quartz crystal and is specified at ±2 ppm from 0 to +40 °C. The DS3231M uses a MEMS resonator, comes in a smaller package and is specified at ±5 ppm. The register map is the same.

Who supplies an alternative to the DS3231M in Europe?

Timing Devices Europe in Ladenburg near Heidelberg, Germany stocks the complete Epson RTC programme in its own warehouse — physically on site, not at the manufacturer. Samples, comparison and series demand in one go, answered the same working day.

Assess a second source

Samples and a comparison for the DS3231M.

Tell us which version you use today, together with quantity and date. We will put together the Epson equivalent with its datasheet and the migration effort — from our own warehouse in Ladenburg near Heidelberg, Germany.

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