RV-3028-C7 vs DS3231 vs PCF8563: I²C RTC Comparison
All three are common I²C real-time clocks with different positioning: the RV-3028-C7 targets ultra-low power, the DS3231 wide-temperature precision (TCXO), and the PCF8563 basic low cost. Compared by key metric below.
| Our pick RV-3028-C7 Micro Crystal | DS3231 Maxim / ADI | PCF8563 NXP | |
|---|---|---|---|
| Interface | I²C | I²C | I²C |
| Timekeeping current (typ) | ~45 nA | ~840 nA | ~250 nA |
| 32.768 kHz crystal | Integrated | Integrated | Integrated |
| Temp compensation | Digital calibration | TCXO (wide-temp) | None |
| Best for | Battery-powered, ultra-low-power | Wide-temp precision | Basic, cost-sensitive |
Which should you choose?
For battery/coin-cell power and long runtime, choose the RV-3028-C7 (~45 nA); for wide-temperature precision, the DS3231. If you currently use the PCF8563, Micro Crystal’s RV-8564 is a register/address-compatible match (firmware ports) — see the cross-reference page.
Cross-references
Frequently asked questions
Why is the RV-3028 so low-power? ▾
The RV-3028-C7 draws ~45 nA timekeeping, far below the DS3231 (~840 nA) and PCF8563 (~250 nA), markedly extending coin-cell life; the trade-off is it lacks the DS3231’s TCXO wide-temperature precision.