DS3231SN#

DS3231SN is a high‑precision I2C Real‑Time Clock (RTC) with a temperature‑compensated oscillator. It keeps accurate time (seconds–year) with automatic leap‑year handling, using an external 32.768 kHz crystal and TCXO for reduced drift. It provides two alarms and a programmable square‑wave/interrupt output. Power range is 2.3–5.5 V, with a VBAT pin to maintain time during power loss. I2C address is 0x68 (default). The SN suffix indicates the small‑outline 8‑pin package variant. Common uses: microcontroller clocks, data logging, scheduling, and time stamping. Benefits: high accuracy (ppm level with temperature compensation), low power, simple I2C interface, and easy integration.

Direct drop-in equivalents for DS3231SN# don’t exist since it’s a high‑precision RTC with an integrated TCXO. Common alternatives (I2C RTCs) include:
- Microchip MCP7940N / MCP79410/11/12
- STMicroelectronics M41T00 / M41T02
- NXP PCF8563
- Renesas/Micro Crystal RV-3028-C7
Note: accuracy, power, memory, and pinouts vary; check compatibility and whether external crystal/battery are required.

DS3231SN features (concise):
- Real-time clock with calendar (leap-year aware); supports 12/24-hour formats.
- Temperature-compensated crystal oscillator (TCXO) with integrated 32.768 kHz crystal; accuracy ±2 ppm from -40°C to +85°C; aging ~0.5 ppm/year.
- VBAT battery-backup input to retain timekeeping when main power is off.
- I2C interface up to 400 kHz; 7-bit address 0x68; operates from 2.3V to 5.5V.
- Two alarms (Alarm 1 and Alarm 2) with multiple match formats; can generate an interrupt.
- Programmable square-wave output (SQW/OUT) with selectable frequencies (1 Hz, 1.024 kHz, 4.096 kHz, 8.192 kHz) or disabled.
- On-chip temperature sensor (-40 to +85°C) with 0.25°C resolution; readable via I2C.
- 8-pin package (DS3231SN); low-power operation suitable for battery-powered devices.

- Pin count: 8 pins (SO-8 package, DS3231SN#)
- Main pin functions:
- VCC: main supply
- GND: ground
- SDA: I2C data
- SCL: I2C clock
- VBAT: battery backup input
- X1 / X2: connections to a 32.768 kHz crystal (oscillator)
- SQW/INT: square-wave output or interrupt output

- Manufacturer: Maxim Integrated (the DS3231SN# is a Maxim Real-Time Clock IC). Maxim Integrated was acquired by Analog Devices in 2021, so the product is now under Analog Devices’ umbrella.
- What kind of company: A semiconductor company specializing in analog and mixed-signal integrated circuits (timing, power management, data converters, sensors, etc.).

DS3231SN is a high-precision I2C real-time clock (RTC) with temperature compensation, battery backup, two alarms and a square-wave output. Common applications include:
- Real-time clocks for microcontrollers and embedded Systems
- Data logging and event timestamping (industrial, environmental, medical)
- Alarm and wake-up timers for low-power designs
- Battery-backed timekeeping in POS, access control, medical devices, automotive modules
- Time base and synchronization for automation, measurement systems, and IoT
- Standalone timestamping in cameras or sensors needing accurate time
(Uses an external 32kHz crystal and provides reliable timekeeping even during power loss.)

DS3231SN# comes in an 8-pin surface-mount SOIC (SOP) package; RoHS compliant.