Spark Logic

DS1307 real-time clock connection guide

DS1307 real-time clock PDIP-8 · 300 mil wiring guide with power, signal assignments, and bench checks.

PDIP-8 · 300 mil

8 contacts Current package
SO-8 · 150 mil 8 contacts

Analog Devices / Maxim Integrated ·

−40 to +85 °C.

Connect an I²C host

Required

Use a 5 V I²C host, a 32.768 kHz crystal with 12.5 pF specified load and no external load capacitors, and a 3 V primary backup cell. Keep X1 and X2 short and away from switching signals. SQW/OUT can stay open.

R1 4.7 kΩ between +5 V and I²C data+5 VR1 4.7 kΩI²C data
R2 4.7 kΩ between +5 V and I²C clock+5 VR2 4.7 kΩI²C clock
C1 100 nF between +5 V and Ground+5 VC1 100 nFGround
Y1 32.768 kHz · 12.5 pF load between Crystal terminal 1 and Crystal terminal 2Crystal terminal 1Y1 32.768 kHz · 12.5 pF loadCrystal terminal 2

Bench checks

  • At up to 100 kHz, look for an acknowledgement at 7-bit address 0x68 with main power on.
  • Write a known time and clear CH in bit 7 of register 0x00. Verify that the seconds advance, then remove and restore main power and compare elapsed time.

Analog Devices / Maxim DS1307 Rev. 5, pp. 1–8.

PDIP-8 · 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

8 · VCC

Supply input · Power

Primary device supply. Place the bypass capacitor close to this pin.

Analog Devices / Maxim DS1307 Rev. 5, pp. 1–8.

Electrical limits · Pin in the reference

Models and documents

This reference covers the 8-lead PDIP and narrow 8-lead SO versions. Both use the same lead numbering.

DS1307+
0 to +70 °C.
DS1307N+
−40 to +85 °C.