82C55A is a high performance CMOS version of the industry standard 8255A from Intersil company. It is compatible with 80C86, 80C88 and other microprocessors, and has 24 programmable I/O pins that support 3 working modes. It is fully compatible with TTL level.
The Intersil 82C55A is a high‑performance CMOS version of the industry‑standard 8255A. It provides 24 programmable I/O pins that can be configured in three operating modes and is fully TTL compatible, making it suitable for a wide range of microprocessor systems.
The datasheet includes pinout diagrams for PDIP, PLCC and MQFP packages, functional block diagrams, mode selection tables, and detailed specifications such as drive capability, standby current, and temperature ranges. Package dimensions for PLCC and MQFP are also provided.
| Programmable I/O pins | 24 |
|---|---|
| TTL compatibility | Fully TTL compatible |
| Drive capability per I/O port | 2.5 mA |
| Standby current (ICCSB) | 10 nA |
| Operating temperature range (PDIP, PLCC, MQFP) | -40 °C to +85 °C |
| Operating temperature range (MD82C55A4/B) | -55 °C to +125 °C |
The 82C55A is pin compatible with the NMOS 82554.
A 0.1 µF capacitor between Vcc and GND is recommended for decoupling.
Each I/O port can source or sink up to 2.5 mA.