74LVX4245MTCX from onsemi, in a TSSOP-24. 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-side supply voltage, 4.5V to 5.5V. Powers the 5V A-port I/O and the control logic; must be powered up before VCCB.
2	T/R	input	Transmit/Receive direction control input, referenced to VCCA. HIGH = A-to-B (transmit); LOW = B-to-A (receive). TTL-compatible.
3	A0	bidirectional	A-side bit 0. 5V bus I/O; sources/sinks 24 mA. Tri-stated when OE is HIGH; direction set by T/R.
4	A1	bidirectional	A-side bit 1. 5V bus I/O; sources/sinks 24 mA. Tri-stated when OE is HIGH; direction set by T/R.
5	A2	bidirectional	A-side bit 2. 5V bus I/O; sources/sinks 24 mA. Tri-stated when OE is HIGH; direction set by T/R.
6	A3	bidirectional	A-side bit 3. 5V bus I/O; sources/sinks 24 mA. Tri-stated when OE is HIGH; direction set by T/R.
7	A4	bidirectional	A-side bit 4. 5V bus I/O; sources/sinks 24 mA. Tri-stated when OE is HIGH; direction set by T/R.
8	A5	bidirectional	A-side bit 5. 5V bus I/O; sources/sinks 24 mA. Tri-stated when OE is HIGH; direction set by T/R.
9	A6	bidirectional	A-side bit 6. 5V bus I/O; sources/sinks 24 mA. Tri-stated when OE is HIGH; direction set by T/R.
10	A7	bidirectional	A-side bit 7. 5V bus I/O; sources/sinks 24 mA. Tri-stated when OE is HIGH; direction set by T/R.
11	GND	power_in	Ground reference for both A- and B-side circuitry. Tie to system ground; both GND pins (11 and 12) must be connected.
12	GND	power_in	Ground reference for both A- and B-side circuitry. Tie to system ground; both GND pins (11 and 12) must be connected.
13	GND	power_in	Ground reference for both A- and B-side circuitry. Tie to system ground; both GND pins (13 and 14) must be connected.
14	GND	power_in	Ground reference for both A- and B-side circuitry. Tie to system ground; both GND pins (13 and 14) must be connected.
15	B7	bidirectional	B-side bit 7. 3V bus I/O; sources/sinks 12 mA. Tri-stated when OE is HIGH; direction set by T/R.
16	B6	bidirectional	B-side bit 6. 3V bus I/O; sources/sinks 12 mA. Tri-stated when OE is HIGH; direction set by T/R.
17	B5	bidirectional	B-side bit 5. 3V bus I/O; sources/sinks 12 mA. Tri-stated when OE is HIGH; direction set by T/R.
18	B4	bidirectional	B-side bit 4. 3V bus I/O; sources/sinks 12 mA. Tri-stated when OE is HIGH; direction set by T/R.
19	B3	bidirectional	B-side bit 3. 3V bus I/O; sources/sinks 12 mA. Tri-stated when OE is HIGH; direction set by T/R.
20	B2	bidirectional	B-side bit 2. 3V bus I/O; sources/sinks 12 mA. Tri-stated when OE is HIGH; direction set by T/R.
21	B1	bidirectional	B-side bit 1. 3V bus I/O; sources/sinks 12 mA. Tri-stated when OE is HIGH; direction set by T/R.
22	B0	bidirectional	B-side bit 0. 3V bus I/O; sources/sinks 12 mA. Tri-stated when OE is HIGH; direction set by T/R.
23	OE	input	Active-LOW Output Enable. When HIGH, both A and B ports are placed in HIGH-Z (3-STATE). TTL-compatible; should ramp with or ahead of VCCA at power-up to prevent bus contention.
24	VCCB	power_in	B-side supply voltage, 2.7V to 3.6V. Powers the 3V B-port I/O; power up after VCCA.

Key specifications

Parameter	Value
Manufacturer	onsemi
Package	TSSOP-24
Category	Logic
Pins	24

Ordering variants

74LVX4245MTCX
74LVX4245MTCXWM
74LVX4245MTCXWMX
74LVX4245MTCXQSC
74LVX4245MTCXQSCX

CAD (KiCad official)

Symbol: 74LVX4245MTCX
Footprint: Package_SO:TSSOP-24_4.4x7.8mm_P0.65mm
3D model: TSSOP-24 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`74lvx4245mtcx.step`	315 KB	You want the bare part, or you mark your own boards.
`74lvx4245mtcx-etched.step`	2.7 MB	You want the part with `74LVX4245MTCX` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 717 faces against 387 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: onsemi datasheet (8 pp, sha256 763a22477bfe4497, retrieved 2026-08-17, tier: manufacturer)
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