ZHCSH81 December 2017 PGA302
PRODUCTION DATA.
The OWI digital communication is a master-slave communication link in which the PGA302 operates as a slave device only. The master device controls when data transmission begins and ends. The slave device does not transmit data back to the master until it is commanded to do so by the master.
The VDD pin of PGA302 is used as OWI interface, so that when PGA302 is embedded inside of a system module, only two pins are needed (VDD and GND) for communication. The OWI master communicates with PGA302 by modulating the voltage on VDD pin while PGA302 communicates with the master by modulating current on VDD pin. The PGA302 processor has the ability to control the activation and deactivation of the OWI interface based upon the OWI Activation pulse driven on VDD pin.
Figure 15 shows a functional equivalent circuit for the structure of the OWI circuitry.