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HT1307ARZ

HTCSEMI · Real-time Clocks (RTC) · SOIC-8

HT1307ARZ from HTCSEMI, in a SOIC-8. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 X1 input Connection to one terminal of the external 32.768 kHz quartz crystal used by the on-chip oscillator. Recommended crystal load capacitance CLX = 12.5 pF.
2 X2 output Connection to the second terminal of the external 32.768 kHz quartz crystal for the on-chip oscillator. Recommended crystal load capacitance CLX = 12.5 pF.
3 VBAT power_in Backup battery supply input, 2.0-3.5 V (absolute max -0.5 to 7.0 V). Sustains timekeeping and RAM when VCC is removed; typical IBAT is 0.5 uA (SQW off) or 0.8 uA (SQW on, 32 kHz on) at VBAT = 3 V.
4 GND power_in Device ground. All voltages are referenced to this pin.
5 SDA bidirectional Serial data I/O for the two-wire (I2C-compatible) bus. Open-drain output requires an external pull-up resistor to VCC. VOL <= 0.4 V at 5 mA sink; total bus capacitance up to 400 pF; supports standard-mode transfers at 100 kHz.
6 SCL input Serial clock input for the two-wire (I2C-compatible) bus. Requires an external pull-up to VCC; input leakage ILI <= 1 uA. Maximum SCL frequency 100 kHz (standard mode).
7 SQW/OUT output Programmable square-wave / general-purpose output. When SQWE (control register bit 4) = 1, outputs 1 Hz, 4.096 kHz, 8.192 kHz, or 32.768 kHz selected by RS1:RS0. When SQWE = 0, the pin is driven to the level of the OUT bit. Open-drain: requires an external pull-up resistor.
8 VCC power_in Primary supply, 4.5-5.5 V (absolute max -0.5 to 7.0 V). When VCC > VBAT + 0.2 V the device operates from VCC; when VCC falls below 1.25 x VBAT the device inhibits access and switches to VBAT. Typical ICC 200 uA static / 1500 uA max during I2C traffic at 100 kHz.

Key specifications

Parameter Value
Manufacturer HTCSEMI
Package SOIC-8
Category RTC
Pins 8

Ordering variants

  • HT1307ARZ

CAD (KiCad official)

  • Symbol: HT1307ARZ
  • Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
  • 3D model: SOIC-8 (KiCad packages3D, STEP)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

  • Datasheet: HTCSEMI datasheet (None pp, sha256 98877efba26d92a8, retrieved 2026-08-17, tier: lcsc)
  • Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF

Symbol & Footprint

Schematic Symbol

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PCB Footprint

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