DS1302S+

DS1302S+ is a low‑power real‑time clock (RTC) IC with on‑chip calendar and 31 bytes of battery‑backed RAM. It keeps time and date (seconds, minutes, hours, day, date, month, year) in BCD, supports leap years, and can run from 2.0–5.5 V. Powered by a backup battery, it maintains time when main power is removed. It uses a simple 3‑wire serial interface (CE, CLK, I/O) instead of I2C or SPI, and typically uses a 32.768 kHz crystal. It’s widely used for clocks, data loggers, alarms, and any application requiring persistent timekeeping. The S+ variant is a newer revision of the DS1302 family, typically pin‑compatible; check the datasheet for exact register map, timing, and electrical details.

Here are the DS1302S+ features (concise):
- Real-time clock/calendar: seconds, minutes, hours (12/24h), day, date, month, year; leap-year aware; year 00–99.
- 32.768 kHz crystal oscillator input for timekeeping.
- Battery-backed operation via VBAT to maintain time when VCC is removed.
- Trickle-charge circuit to keep a backup battery charged from main supply (external diode/resistor required).
- 31 bytes of general-purpose RAM (battery-backed) accessible via the serial interface.
- 3-wire serial interface (CE, CLK, I/O) for time and RAM read/write.
- Programmable square-wave output on SQW/OUT.
- Wide operating voltage: typically 2.0 to 5.5 V.
- Industrial temperature range: approximately -40°C to +85°C.
- Small package options (8-pin variants) suitable for compact designs.
- Low power consumption, especially in battery mode.

- Pin count: 8 pins (DIP8/SOP-8).
- Primary functions (3-wire serial RTC with trickle-charge):
- VCC: Main supply
- GND: Ground
- VBAT: Backup supply (battery) when VCC is off
- X1, X2: Trickle-charge network terminals for the backup battery
- CE: Chip Enable for initiating a serial transfer
- CLK: Serial clock input
- IO: Bidirectional data line (serial data)
Notes: DS1302S+ is a real-time clock/calendar with a 3-wire interface (CE, CLK, IO) and a trickle-charge feature using X1/X2, plus battery backup via VBAT.

- Manufacturer: Dallas Semiconductor (the DS1302 family; the brand is now part of Maxim Integrated, which is in turn part of Analog Devices).
- What kind of company: A semiconductor company that designs and manufactures integrated circuits (ICs), including real-time clocks and other analog/mixed-signal devices.

DS1302S+ is a low‑power, battery‑backed real‑time clock with RAM and trickle‑charge. Common applications:
- Microcontroller/embedded systems needing accurate time (scheduling, timing, alarms)
- Data logging and event/time stamping (sensors, environmental monitoring)
- Digital clocks, alarm clocks, timers, wearables
- Battery‑backed timekeeping for portable instruments during power loss
- IoT/smart home devices and timing control
- Industrial automation, metering, test equipment for sequencing and logging

DS1302S+ is an 8-pin device, available in common DIP-8 (through-hole) and SOIC-8 (surface-mount) packages.