UM3204UE from Union Semiconductor, in a TSSOP-14. 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	VCCA	power_in	A-port supply voltage. Sets logic levels for the A-side I/Os and the OE input. Range 1.65V ≤ VCCA ≤ 3.6V, and must satisfy VCCA ≤ VCCB.
2	A1	bidirectional	Channel 1 bidirectional data I/O, referenced to VCCA (low-voltage side). Placed in high-impedance state when OE is low.
3	A2	bidirectional	Channel 2 bidirectional data I/O, referenced to VCCA (low-voltage side). Placed in high-impedance state when OE is low.
4	A3	bidirectional	Channel 3 bidirectional data I/O, referenced to VCCA (low-voltage side). Placed in high-impedance state when OE is low.
5	A4	bidirectional	Channel 4 bidirectional data I/O, referenced to VCCA (low-voltage side). Placed in high-impedance state when OE is low.
6	NC	unconnected	No internal connection. May be left floating or tied to any potential within absolute-maximum ratings.
7	GND	power_in	Ground reference for both supply rails and all I/O.
8	OE	input	Three-state output enable, referenced to VCCA. Pull OE low to place all A and B outputs in high-impedance (three-state) mode; drive high for normal bidirectional translation.
9	NC	unconnected	No internal connection. May be left floating or tied to any potential within absolute-maximum ratings.
10	B4	bidirectional	Channel 4 bidirectional data I/O, referenced to VCCB (high-voltage side). Includes ±5 kV ESD protection. Placed in high-impedance state when OE is low.
11	B3	bidirectional	Channel 3 bidirectional data I/O, referenced to VCCB (high-voltage side). Includes ±5 kV ESD protection. Placed in high-impedance state when OE is low.
12	B2	bidirectional	Channel 2 bidirectional data I/O, referenced to VCCB (high-voltage side). Includes ±5 kV ESD protection. Placed in high-impedance state when OE is low.
13	B1	bidirectional	Channel 1 bidirectional data I/O, referenced to VCCB (high-voltage side). Includes ±5 kV ESD protection. Placed in high-impedance state when OE is low.
14	VCCB	power_in	B-port supply voltage. Sets logic levels for the B-side I/Os. Range 2.3V ≤ VCCB ≤ 5.5V. Either VCCA or VCCB may be ramped first (no supply sequencing required).

Key specifications

Parameter	Value
Manufacturer	Union Semiconductor
Package	TSSOP-14
Category	Logic
Pins	14

Ordering variants

Same part, different packaging or reel option.

UM3204UE
UM3204UEQ
UM3204UEQS
UM3204UEQT
UM3204UEH

CAD (KiCad official)

Symbol: UM3204UE
Footprint: Package_SO:TSSOP-14_4.4x5mm_P0.65mm
3D model: TSSOP-14 (KiCad packages3D, STEP)

Provenance

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

Datasheet: Union Semiconductor datasheet (17 pp, sha256 40d808e0d0a3f5e5, 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