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RX-8731LC
Real-time clock module by Epson

The RX-8731LC is a real-time clock module from Epson with a built-in 32.768 kHz crystal — no separate watch crystal on the board, no load capacitance and layout risk. Interface I²C, package LC · VSOJ-12, 3.6 × 2.8 mm, standby current 350 nA typ., accuracy ±23 ppm @ +25 °C, operating range −40 … +85 °C.

I²CLC VSOJ-12 3.6 × 2.8
InterfaceI²C
PackageLC · VSOJ-12, 3.6 × 2.8 mm
Standby current350 nA typ.
Accuracy±23 ppm @ +25 °C
Temperature range−40 … +85 °C
Supply1.3–5.5 V
AvailabilityEx stock Ladenburg near Heidelberg

What the RX-8731LC can do

No DTCXO

The tolerance figure applies at +25 °C. Over temperature the built-in crystal follows the usual parabola.

Order codes and datasheets

Every order code has its own printable datasheet with all recorded figures.

TDE itemEpson designation
91-0151RX-8731LC B
91-0152RX-8731LC B
91-0153RX-8731LC B

Alternatives in the Epson programme

If the RX-8731LC is not quite the right fit — these types come closest:

All 40 families with filters for interface, package, standby current and temperature: real-time clock finder.

Frequently asked questions about the RX-8731LC

How accurate is the RX-8731LC?

±23 ppm @ +25 °C. This figure applies at +25 degrees Celsius. Over temperature the built-in crystal follows the usual parabola — if the clock has to hold when hot and cold as well, a DTCXO type is the right choice.

How much current does the RX-8731LC draw in backup?

350 nA typ.. With a 225 mAh coin cell that is enough for many years of pure timekeeping on paper; the self-discharge of the cell usually becomes the limiting factor.

Which interface does the RX-8731LC use?

I²C. Package: LC · VSOJ-12, 3.6 × 2.8 mm.

Where can I buy the RX-8731LC in Europe?

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

Samples and series demand

Enquire about the RX-8731LC.

We stock the Epson RTC programme in our own warehouse in Ladenburg near Heidelberg, Germany. Tell us tolerance grade, packing, quantity and date — answered the same working day.

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