Spark Logic

DS3232 real-time clock connection guide

DS3232 real-time clock SO-20 · 300 mil wiring guide with power, signal assignments, and bench checks.

SO-20 · 300 mil

20 contacts Current package

Analog Devices / Maxim Integrated ·

Connect an I²C host

Required

Connect a 3 V primary cell to VBAT and connect all NC leads to ground. Leave 32kHz, INT/SQW and RST open if the host uses only the serial clock and calendar. The circuit ties both SCL pins together.

R1 4.7 kΩ between +3.3 V and I²C data+3.3 VR1 4.7 kΩI²C data
R2 4.7 kΩ between +3.3 V and I²C clock+3.3 VR2 4.7 kΩI²C clock
C1 100 nF between +3.3 V and Ground+3.3 VC1 100 nFGround

Bench checks

  • With VCC above the power-fail threshold, find 0x68 and read registers 0x00–0x06.
  • Set a known time and clear the oscillator-stop flag in status register 0x0F after confirming that the oscillator is running.
  • Remove main power briefly, then restore it and confirm that the clock advanced.

Analog Devices / Maxim DS3232 datasheet, electrical characteristics, pin description, and typical operating circuit.

SO-20 · 300 mil wiring map

Highlighted contacts are used in the required step or selected circuit. Select a contact to inspect it.

Top view. Start at the package pin-1 index and follow the numbered leads.
Selected pin details

16 · VBAT

Supply input · Power

Backup supply input. Ground it when no backup source is used.

Analog Devices / Maxim DS3232 datasheet, electrical characteristics, pin description, and typical operating circuit.

Electrical limits · Pin in the reference

Models and documents

This map covers the 20-lead wide SO package. Pins 18 and 20 both carry SCL. Connect either one or both to the same net.

DS3232S#
0 to +70 °C.
DS3232SN#
−40 to +85 °C.