DS1302ZM from HGSEMI, in a SOP-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	VCC2	power_in	Primary power supply pin in a dual-supply configuration (2.0-5.5V). DS1302 draws from the larger of VCC1 or VCC2; VCC2 powers the chip when VCC2 > VCC1 + 0.2V.
2	X1	passive	Connection for a 32.768 kHz quartz crystal (specified load capacitance 6 pF). May alternatively be driven by an external 32.768 kHz oscillator signal (with X2 floated).
3	X2	passive	Connection for a 32.768 kHz quartz crystal (specified load capacitance 6 pF). Leave floating if X1 is driven by an external oscillator.
4	GND	power_in	Device ground reference.
5	RST	input	Reset / chip-enable input (active high per the datasheet: 'The reset signal must be asserted high during a read or a write'). Initiates all data transfers and can terminate single- or multi-byte transfers; when low, the I/O pin goes to high impedance.
6	I/O	bidirectional	Bi-directional serial data pin for the 3-wire interface. Tri-states on each rising edge of SCLK during data output; data is clocked in on rising edges and out on falling edges of SCLK.
7	SCLK	input	Serial clock input used to synchronize data movement on the 3-wire serial interface. Must be at logic 0 when RST is driven high.
8	VCC1	power_in	Backup/low-power supply pin (2.0-5.5V). Connects to a battery or, when the trickle charger is used, to a rechargeable cell or super-cap; powers the DS1302 whenever VCC2 < VCC1.

Key specifications

Parameter	Value
Manufacturer	HGSEMI
Package	SOP-8
Category	RTC
Pins	8

Ordering variants

Same part, different packaging or reel option.

DS1302ZM/TR
DS1302M/TR
DS1302N
DS1302ZN
DS1302MM/TR
DS1302ZMM/TR
DS1302DQ/TR
DS1302DQ3/TR
DS1302ZDQ/TR
DS1302ZDQ3/TR

CAD (KiCad official)

Symbol: DS1302ZM
Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
3D model: SOP-8 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`ds1302zm.step`	122 KB	You want the bare part, or you mark your own boards.
`ds1302zm-etched.step`	1.9 MB	You want the part with `DS1302ZM` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 460 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: HGSEMI datasheet (16 pp, sha256 3fcd6fbdc5e0c4e6, 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