What Is the ADC0804? 8-bit Parallel ADC and Uses
The ADC0804 is a classic 8-bit single-channel, parallel-output ADC. It converts one analog voltage into an 8-bit value (0–255) on 8 parallel lines. Being a parallel interface it connects directly to 8 pins of a microcontroller; common in classic systems like the 8051 and in teaching. An external RC clock sets conversion speed, the VREF/2 pin sets the range.
The ADC0804 is a classic 8-bit, parallel-output ADC (analog-to-digital converter). It is a single-channel, parallel-interface old but instructive chip, common in classic microcontroller projects like the 8051 and in electronics teaching. For the concept, see what is an ADC.
What is the ADC0804 used for?
It converts a single analog voltage into an 8-bit digital value (0–255) and presents it on 8 parallel output lines. Being a parallel interface it connects directly to 8 pins of a microcontroller; handy in classic systems that don't speak SPI/I²C.
Specifications
| Parameter | Value |
|---|---|
| Resolution | 8-bit (0–255) |
| Channel | 1 (differential input) |
| Interface | Parallel (8 lines) + WR/RD/CS/INTR |
| Supply | 5 V |
Watch out
The conversion is timed by a clock circuit, usually set with an external RC. The VREF/2 pin sets the measurement range. Being 8-bit and single-channel it has largely given way to I²C/SPI ADCs in modern projects. The parallel lines take up many pins.
Equivalents
- MCP3008: 8-channel 10-bit SPI (fewer pins).
- ADS1115: 16-bit I²C (far more precise).
- ADC0808/0809: an 8-channel parallel relative.
Find it in our catalog
Use the ADC0804 search.