74HC244D,653

74HC244D is an octal buffer/line driver with 3-state outputs. It buffers eight data lines and splits them into two 4-bit sections, each with its own active-low output enable (OE1 and OE2). When an enable is low, the corresponding four outputs drive the inputs; when high, those outputs go tri-state, effectively disconnecting the bus. This lets you isolate devices on a shared data bus and adds drive strength where needed. It’s a CMOS HC device, typically powered from Vcc = 2–6 V (5 V common), with TTL-compatible inputs and moderate switching speeds. The device is packaged as 20-pin (DIP/SOIC), with inputs on one side, outputs on the other.
On “653”: please confirm the exact part number (e.g., 74HC653 or another variant). I can provide a concise intro for the intended device once you specify.

74HC244D is an octal buffer/line driver with 3-state outputs. Equivalents across vendors/families include:
- SN74HC244D (TI)
- SN74HCT244D (TI)
- 74HC244 (NXP/ON/ST variants)
- 74VHC244 (Nexperia/ST)
- 74LVC244 (low-voltage variants)
- 74ALS244 (Fairchild)
Voltage compatibility and pinout are usually identical; verify package suffix (D, N, etc.).

Here are the typical features of these HC family parts:
74HC244D
- Octal buffer/line driver with 3-state outputs
- Two groups of four buffers; two separate enables (1OE and 2OE), active-low
- Non-inverting outputs
- 2V to 6V operation (CMOS HC family), high-speed
- Low static power consumption
- Outputs go high impedance when disabled
- Suitable for bidirectional data bus buffering
- Available in common packages (e.g., DIP, SOIC; suffix D indicates a specific package option)
74HC653
- 8-bit buffer/driver or latch-type device with 3-state outputs (bus interface device)
- Separate control inputs (e.g., enable and/or latch control, plus OE for 3-state)
- CMOS HC technology: 2V–6V operation; fast switching
- Low power consumption
- High drive capability for bus lines
- Multiple package options (DIP/SOIC, etc.)
Note: Exact pinout and control names can vary by manufacturer; verify in the specific datasheet for your device/package.

- 74HC244D
- Pin count: 20 pins (DIP; also available in other packages)
- Function: Octal buffer/line driver with 3-state outputs; two 4-bit buffers with separate active-low enable pins (one for each group).
- 74HC653
- Pin count: 20 pins (DIP; also available in other packages)
- Function: 8-bit latch/register with 3-state outputs; data inputs D0–D7, a latch/clock enable, and an output enable to tri-state the outputs; used for buffering/latching bus lines.

- Manufacturer: Texas Instruments (TI)
- Company type: American multinational semiconductor company that designs and manufactures integrated circuits and other electronics components (analog and digital ICs for various markets).

- 74HC244D: Octal buffer/line driver with 3-state outputs. Applications: buffering CPU data buses, isolating RAM/ROM and peripherals, reducing bus loading, and enabling/disabling the 8 data lines; common in microprocessor/microcontroller bus interfacing and bus sharing.
- 74HC653: 8-bit D-type transparent latch with 3-state outputs. Applications: latching/holding address or data on multiplexed buses, demultiplexing memory interfaces, implementing register banks and I/O expansion, and providing stable bus lines to external devices.

20-pin Plastic DIP (DIP-20); the D suffix generally denotes DIP packaging (some vendors also offer an SOIC‑20 variant—check the specific datasheet).