DS1307
Epson alternative: RX8130CE
The DS1307 is one of the oldest RTCs still designed in — and one of the most restrictive. It needs 5 V, it needs an external crystal, and its I²C runs at 100 kHz. If a design is being refreshed anyway, this is what the change looks like. The same applies to the 3.3 V relative, the DS1338.
The DS1307 carries 56 bytes of battery-backed RAM and a programmable square-wave output.
DS1307 versus RX8130CE
| DS1307 — Analog Devices | RX8130CE — Epson | |
|---|---|---|
| Manufacturer | Analog Devices (formerly Maxim, originally Dallas) | Epson (Seiko Epson) |
| Interface | I²C, 100 kHz (standard mode only) | I²C (400 kHz) |
| Crystal integrated | no — external 32.768 kHz crystal required | yes, factory calibrated |
| Accuracy | depends on the crystal used and on how well its load capacitance is matched | +5 ±23 ppm at +25 °C (not compensated) |
| Supply | 4.5 – 5.5 V · backup 2.0 – 3.5 V | 1.25 – 5.5 V |
| Timekeeping current | 300 – 500 nA typ. · 800 nA max. | 300 nA typ. · 500 nA max. |
| Max. temperature | +85 °C (industrial) · +70 °C (commercial) | −40 … +85 °C |
| Package | DIP-8 (300 mil) or SO-8 (150 mil) | CE 3.2 × 2.5 × 1.0 mm · 8.0 mm² footprint |
| Extras | 56 byte battery-backed RAM, square-wave output | reset output with delay, charge control with full-charge detection, V_IO pin |
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.
Honestly
- 56 bytes of battery-backed RAM, which the Epson type does not carry
- Available in a DIP package — still useful for repairs and small runs
- Very well documented, with drivers everywhere
The difference
- The DS1307 is an RTC IC WITHOUT a crystal. You need an additional 32.768 kHz crystal, have to match its load capacitance to the device and carry the layout and spread risk of the oscillator loop yourself. Epson delivers the module with the calibrated crystal inside: one component instead of three
- Supply: the DS1307 needs 4.5 V at minimum. The RX8130CE starts at 1.25 V, so it fits a 3.3 V design without a level shifter
- I²C at 400 kHz instead of 100 kHz
- A reset output with a selectable delay, charge control with full-charge detection and a separate V_IO pin — none of which the DS1307 has
Frequently asked questions
What is the Epson alternative to the DS1307?
The RX8130CE is the natural replacement, with the RX-8564LC as the second option where a pin-compatible route to the NXP world matters. Neither is a drop-in: package, pinout and register map differ.
Does the DS1307 need an external crystal?
Yes. The DS1307 is an RTC IC without a built-in crystal — you need an additional 32.768 kHz crystal and the accuracy then depends on that crystal and on how well its load capacitance is matched to the device. The Epson modules carry the calibrated crystal inside the package.
Can the DS1307 run at 3.3 V?
Not on its main supply — the datasheet specifies 4.5 to 5.5 V. The DS1338 is the 3.3 V relative. Epson's RX8130CE runs from 1.25 V upwards and covers both cases.
Who supplies an alternative to the DS1307 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.
Samples and a comparison for the DS1307.
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.