HT1302ARZ from HTCSEMI, in a SOP-8-150mil. 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	VCC2	power_in	Primary power-supply pin in dual-supply configuration (typ 2.0V-5.5V). The HT1302 operates from the larger of VCC1 or VCC2; when VCC2 > VCC1 + 0.2V, VCC2 powers the chip. When VCC2 < VCC1, VCC1 powers the chip.
2	X1	passive	Connection for a standard 32.768kHz quartz crystal (specified load capacitance 6pF). Can alternatively be driven by an external 32.768kHz oscillator, in which case X2 is left floating.
3	X2	passive	Second connection for the 32.768kHz quartz crystal. Floated when the oscillator is driven by an external clock on X1.
4	GND	power_in	Ground reference for the device.
5	CE	input	Chip enable input. Must be asserted high during a read or a write to initiate a data transfer. This pin has an internal 40kΩ (typical) pulldown resistor to ground. Previously referred to as /RST in older revisions; functionality unchanged.
6	I/O	bidirectional	Bidirectional data pin for the 3-wire serial interface (push-pull output when driving). Tri-stated when not driving read data. Has an internal 40kΩ (typical) pulldown resistor to ground.
7	SCLK	input	Serial clock input used to synchronize data movement on the 3-wire serial interface. Has an internal 40kΩ (typical) pulldown resistor to ground.
8	VCC1	power_in	Backup/secondary power supply for low-power operation and battery backup. In trickle-charger systems, the rechargeable energy source (e.g. lithium coin cell or supercapacitor) is connected here. UL recognized to guard against reverse charging current when used with a lithium battery.

Key specifications

Parameter	Value
Manufacturer	HTCSEMI
Package	SOP-8-150mil
Category	RTC
Pins	8

Ordering variants

Same part, different packaging or reel option.

HT1302ARZ

CAD (KiCad official)

Symbol: HT1302ARZ
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOP-8-150mil (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`ht1302arz.step`	122 KB	You want the bare part, or you mark your own boards.
`ht1302arz-etched.step`	1.8 MB	You want the part with `HT1302ARZ` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 462 faces against 147 in the bare model. It survives export, section views, and rendering in any CAD tool, and it drops straight into KiCad or Fusion with no extra setup.

Provenance

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

Datasheet: HTCSEMI datasheet (14 pp, sha256 729f4ecc174f49dc, 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