74ACT244MTCX from onsemi, in a TSSOP-20. 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	OE1#	input	Active-low 3-STATE output enable for bank 1 (outputs O0..O3 on pins 18, 16, 14, 12). When LOW, bank 1 outputs follow their corresponding inputs; when HIGH, bank 1 outputs are placed in high-impedance state.
2	I0	input	Bank 1 data input 0. Buffered non-inverting path to output O0 (pin 18) when OE1# is asserted low.
3	O4	tri_state	Bank 2 data output 4. Non-inverting buffered copy of I4 (pin 17) when OE2# is asserted low; high-Z otherwise. Drives 24 mA source/sink.
4	I1	input	Bank 1 data input 1. Buffered non-inverting path to output O1 (pin 16) when OE1# is asserted low.
5	O5	tri_state	Bank 2 data output 5. Non-inverting buffered copy of I5 (pin 15) when OE2# is asserted low; high-Z otherwise. Drives 24 mA source/sink.
6	I2	input	Bank 1 data input 2. Buffered non-inverting path to output O2 (pin 14) when OE1# is asserted low.
7	O6	tri_state	Bank 2 data output 6. Non-inverting buffered copy of I6 (pin 13) when OE2# is asserted low; high-Z otherwise. Drives 24 mA source/sink.
8	I3	input	Bank 1 data input 3. Buffered non-inverting path to output O3 (pin 12) when OE1# is asserted low.
9	O7	tri_state	Bank 2 data output 7. Non-inverting buffered copy of I7 (pin 11) when OE2# is asserted low; high-Z otherwise. Drives 24 mA source/sink.
10	GND	power_in	Device ground reference (0 V). Common return for VCC and all input/output signals.
11	I7	input	Bank 2 data input 7. Buffered non-inverting path to output O7 (pin 9) when OE2# is asserted low.
12	O3	tri_state	Bank 1 data output 3. Non-inverting buffered copy of I3 (pin 8) when OE1# is asserted low; high-Z otherwise. Drives 24 mA source/sink.
13	I6	input	Bank 2 data input 6. Buffered non-inverting path to output O6 (pin 7) when OE2# is asserted low.
14	O2	tri_state	Bank 1 data output 2. Non-inverting buffered copy of I2 (pin 6) when OE1# is asserted low; high-Z otherwise. Drives 24 mA source/sink.
15	I5	input	Bank 2 data input 5. Buffered non-inverting path to output O5 (pin 5) when OE2# is asserted low.
16	O1	tri_state	Bank 1 data output 1. Non-inverting buffered copy of I1 (pin 4) when OE1# is asserted low; high-Z otherwise. Drives 24 mA source/sink.
17	I4	input	Bank 2 data input 4. Buffered non-inverting path to output O4 (pin 3) when OE2# is asserted low.
18	O0	tri_state	Bank 1 data output 0. Non-inverting buffered copy of I0 (pin 2) when OE1# is asserted low; high-Z otherwise. Drives 24 mA source/sink.
19	OE2#	input	Active-low 3-STATE output enable for bank 2 (outputs O4..O7 on pins 3, 5, 7, 9). When LOW, bank 2 outputs follow their corresponding inputs; when HIGH, bank 2 outputs are placed in high-impedance state.
20	VCC	power_in	Positive supply voltage. Recommended 4.5 V to 5.5 V for ACT variant (2.0 V to 6.0 V for AC). Absolute maximum 7.0 V. Bypass locally with a 0.1 uF ceramic to GND.

Key specifications

Parameter	Value
Manufacturer	onsemi
Package	TSSOP-20
Category	Logic
Pins	20

Ordering variants

74ACT244MTCX
74ACT244MTCX_NL
74ACT244MTCXSC
74ACT244MTCXSCX_NL
74ACT244MTCXSJ
74ACT244MTCXMSA
74ACT244MTCXPC

CAD (KiCad official)

Symbol: 74ACT244MTCX
Footprint: Package_SO:TSSOP-20_4.4x6.5mm_P0.65mm
3D model: TSSOP-20 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File	Size	Use it when
`74act244mtcx.step`	267 KB	You want the bare part, or you mark your own boards.
`74act244mtcx-etched.step`	2.4 MB	You want the part with `74ACT244MTCX` already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 643 faces against 327 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 (10 pp, sha256 1bc5281d72501096, 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