Behavioural mixed-signal modelDS3231SN#ds3231
DS3231 (real-time clock, I²C)
Precise I²C real-time clock (±2 ppm, crystal inside) at address 0x68: seconds … year in BCD, two alarms on INT/SQW, square wave, temperature register. The clock starts at the set date and time and runs with the simulation time. Read e.g. with RTClib.
Key data
- Category
- ICs
- Simulation model
- Behavioural mixed-signal model
- Manufacturer part number
- DS3231SN#
- Reference prefix
- U
- Pins
- 8
- Land pattern
- SOIC-16W_7.5x10.3mm_P1.27mm
Notes
- Set the start date and time in the inspector; the firmware reads it in BCD from registers 00h–06h.
- INT/SQW and 32kHz are open-drain outputs: they need a pull-up resistor.
Simulation model
A behavioural model implements the interface of the chip (registers, protocol, timing) at its pins. The pins are connected to the analog circuit like CMOS pins.
- Model
- ds3231
- Supply pins
- VCC / GND
Pins 8
| Pin | Name | Use |
|---|---|---|
| VCC | VCCSupply pin | Supply 2.3–5.5 V: 100 nF to GND |
| VBAT | VBATSupply pin | Backup cell (CR2032) or GND when no battery is used |
| RST | RST̅Output pin · pulled up on the board | Reset output, active low (internal 50 kΩ pull-up): low at power-up and during brown-out |
| GND | GNDGround pin | Ground |
| SCL | SCLInput pin | I²C clock: pull-up (about 4.7 kΩ) to the supply |
| SDA | SDAI/O pin | I²C data: pull-up (about 4.7 kΩ) to the supply |
| INT | INT/SQWOutput pin | Alarm interrupt or square wave (open drain): pull-up resistor to the supply |
| 32K | 32kHzOutput pin | 32.768 kHz output (open drain): pull-up resistor, or leave open |
Parameters 3
Date and time at start
startDefault2026-01-01 12:00:00
YYYY-MM-DD hh:mm:ss; the clock then runs with the simulation time
Temperature
templiveDefault25 °C
Simulate the 32 kHz output
sim32kDefaultoff
65 536 edges per simulated second: slows the simulation down
PCB
Verified land pattern
SOIC-16W_7.5x10.3mm_P1.27mm| Package | Land pattern | Status | Source |
|---|---|---|---|
| SOIC-16W · DS3231SN# | SOIC-16W_7.5x10.3mm_P1.27mm | Verified land pattern | KiCad Package_SO:SOIC-16W_7.5x10.3mm_P1.27mm; DS3231 datasheet pinout 1 32kHz, 2 VCC, 3 INT/SQW, 4 RST, 5–12 N.C. (grounded), 13 GND, 14 VBAT, 15 SDA, 16 SCL |
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