The ISL1209 is a low-power real-time clock (RTC) from Intersil that features event detection, timing and crystal compensation, clock/calendar, power fail indicator, periodic or polled alarm, intelligent battery backup switching and battery-backed user SRAM.
The ISL1209 is a low‑power real‑time clock/calendar IC that provides time‑keeping, alarm, event detection, and a 2‑byte battery‑backed SRAM. It operates from a 2.7 V to 5.5 V supply and can switch to a backup source (battery or super‑capacitor) when main power is lost.
Key features include 15 selectable frequency outputs, a programmable interrupt/frequency pin, tamper/event detection with optional glitch filtering, and an I²C interface capable of 400 kHz data transfers. The device is supplied in a 10‑lead MSOP package and is RoHS‑compliant.
| Supply voltage (VDD) | 2.7‑5.5 V |
|---|---|
| Backup supply voltage (VBAT) | 1.8‑5.5 V |
| Package | 10‑lead MSOP |
| Supply current (IDD1) at VDD=5 V | ≈2‑6 µA |
| I²C data rate | 400 kHz |
| Operating temperature range | -40 °C to +85 °C |
The I²C interface operates at a 400 kHz data transfer rate.
In low‑power mode (LPMODE = 1) the device draws about 1.4 µA at VDD = 5 V.
The battery supply current (IBAT) is between 400 nA and 950 nA at VBAT = 3 V.
The ISL1209 provides 15 selectable frequency outputs.