PCA9704 Overview
The PCA9704 is a low power 18 V tolerant SPI General Purpose Input (GPI) shift register designed to monitor the status of switch inputs. It generates an interrupt when one or more of the switch inputs change state but allows selected inputs to not generate interrupts using the interrupt masking.
PCA9704 Key Features
- 8 general purpose input ports
- 18 V tolerant input ports with 100 k external series resistor
- Input LOW threshold 0.55 VDD with minimum of 2.5 V at VDD = 4.5 V
- Open-drain interrupt output
- Interrupt enable pin (INT_EN) disables GPI pins and interrupt output
- Interrupt-masking feature allows no interrupt generation from selected inputs
- VDD range: 4.5 V to 5.5 V
- IDD is very low 2.5 A maximum
- SPI serial interface with speeds up to 5 MHz
- SPI supports daisy-chain connection for large switch numbers