The ISL1220 is a low power real time clock with timing and crystal compensation, clock/calendar, power fail indicator, periodic or polled alarm, intelligent battery backup switching, battery-backed user SRAM and separate FOUT and IRQ outputs.
The ISL1220 is a low‑power real‑time clock with calendar, 8 bytes of battery‑backed SRAM, a programmable frequency‑output pin and a single interrupt pin. It operates from a 2.7 V‑5.5 V main supply and can switch to a backup supply (1.8 V‑5.5 V) when power is lost.
The device uses a 32.768 kHz crystal, provides automatic leap‑year correction, and supports I²C communication up to 400 kHz. It includes features such as low‑power mode, InterSeal™ Battery Saver, and a 15‑selectable frequency output, making it suitable for utility meters, HVAC, audio/video equipment, and many other applications.
| Supply Voltage (Vpp) | 2.7 V to 5.5 V |
|---|---|
| Battery Supply Voltage (Vbat) | 1.8 V to 5.5 V |
| Supply Current (Ipp1) at Vpp=5 V | 2 µA |
| Frequency Output Options | 15 selectable frequencies |
| Battery‑Backed SRAM | 8 bytes |
| Package | 10‑lead MSOP |
It is the Fout pin, an open‑drain output that can be programmed to be active or disabled.
The device includes 8 bytes of battery‑backed user SRAM.
Vpp can be supplied from 2.7 V up to 5.5 V.