This manual introduces the features and functions of ZiLOG Z86D990/Z86D991 OTP and Z86L99X ROM low-voltage microcontrollers.
The Z86D990/Z86D991 OTP and Z86L99X ROM microcontrollers are low‑voltage, general‑purpose devices featuring a four‑channel 8‑bit sigma‑delta ADC and a flexible Z8 core. They target embedded control applications such as battery chargers, home appliances, IR remote controls, security systems, and wireless keyboards.
The document provides an architectural overview, pin descriptions, electrical characteristics, and design considerations, along with ordering information and a comparison of the different device variants.
| Operating voltage (Z86D990/Z86D991) | 3.0 V to 5.5 V |
|---|---|
| Operating voltage (Z86L99X) | 2.3 V to 5.5 V |
| ADC channels | Four‑channel 8‑bit sigma‑delta |
| RAM (total) | 489 bytes |
| RAM mapped into program space | 256 bytes |
| OTP memory (Z86D99) | 32 KB |
| ROM memory (Z86L99X) | 16 KB |
| I/O pins | 32 (up to 48 in larger packages) |
| Counter/Timers | Three counters, including an 8‑bit and a 16‑bit counter/timer pair |
The Z86D990 operates from 3.0 V to 5.5 V.
It includes a four‑channel 8‑bit sigma‑delta ADC.
Each device has 489 bytes of RAM, with 256 bytes mapped into the program memory space.
The Z86L99X uses 16 KB of ROM.