HTM1640 from TDSEMIC, in a SSOP-28. 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	GRID12	output	Digit (grid) output 12. N-channel open-drain output driving a common-cathode digit line; up to 200 mA sink current.
2	GRID13	output	Digit (grid) output 13. N-channel open-drain output driving a common-cathode digit line.
3	GRID14	output	Digit (grid) output 14. N-channel open-drain output driving a common-cathode digit line.
4	GRID15	output	Digit (grid) output 15. N-channel open-drain output driving a common-cathode digit line.
5	GRID16	output	Digit (grid) output 16. N-channel open-drain output driving a common-cathode digit line.
6	VSS	power_in	Logic ground. Connect to system ground (0 V). Also labeled GND on the pinout diagram.
7	DIN	input	Serial data input. Data is changed while SCLK is low and latched when SCLK is high; transmitted LSB first. Also labeled DATA on the pinout diagram.
8	SCLK	input	Serial clock input. Data on DIN is sampled on the rising edge. VIH = 0.7VDD, VIL = 0.3VDD, 0.35 V hysteresis. Also labeled CLK on the pinout diagram.
9	SEG1	output	Segment output 1. P-channel open-drain (source) output driving an LED anode line; up to 50 mA source current.
10	SEG2	output	Segment output 2. P-channel open-drain (source) output driving an LED anode line.
11	SEG3	output	Segment output 3. P-channel open-drain (source) output driving an LED anode line.
12	SEG4	output	Segment output 4. P-channel open-drain (source) output driving an LED anode line.
13	SEG5	output	Segment output 5. P-channel open-drain (source) output driving an LED anode line.
14	SEG6	output	Segment output 6. P-channel open-drain (source) output driving an LED anode line.
15	SEG7	output	Segment output 7. P-channel open-drain (source) output driving an LED anode line.
16	SEG8	output	Segment output 8. P-channel open-drain (source) output driving an LED anode line.
17	VDD	power_in	Logic power supply. Recommended 5 V ±10% (3.0 V to 5.5 V operating range). Absolute maximum -0.5 V to +7.0 V.
18	GRID1	output	Digit (grid) output 1. N-channel open-drain output driving a common-cathode digit line; up to 200 mA sink current.
19	GRID2	output	Digit (grid) output 2. N-channel open-drain output driving a common-cathode digit line.
20	GRID3	output	Digit (grid) output 3. N-channel open-drain output driving a common-cathode digit line.
21	GRID4	output	Digit (grid) output 4. N-channel open-drain output driving a common-cathode digit line.
22	GRID5	output	Digit (grid) output 5. N-channel open-drain output driving a common-cathode digit line.
23	GRID6	output	Digit (grid) output 6. N-channel open-drain output driving a common-cathode digit line.
24	GRID7	output	Digit (grid) output 7. N-channel open-drain output driving a common-cathode digit line.
25	GRID8	output	Digit (grid) output 8. N-channel open-drain output driving a common-cathode digit line.
26	GRID9	output	Digit (grid) output 9. N-channel open-drain output driving a common-cathode digit line.
27	GRID10	output	Digit (grid) output 10. N-channel open-drain output driving a common-cathode digit line.
28	GRID11	output	Digit (grid) output 11. N-channel open-drain output driving a common-cathode digit line.

Key specifications

Parameter	Value
Manufacturer	TDSEMIC
Package	SSOP-28
Category	LED Drivers
Pins	28

Ordering variants

Same part, different packaging or reel option.

HTM1640SSOP28
HTM1640SOP28

CAD (KiCad official)

Symbol: HTM1640
Footprint: Package_SO:SSOP-28_5.3x10.2mm_P0.65mm
3D model: SSOP-28 (KiCad packages3D, STEP)

Provenance

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

Datasheet: TDSEMIC datasheet (14 pp, sha256 da626725a5629030, retrieved 2026-08-17, tier: lcsc)
Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
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