SBOA103C
Jan 2006
PGA309 Quick Start
System Reference Guide
96
PGA309 In Three Wire Mode
In many cases the PGA309 is connected in a configuration referred to as a three wire connection. In this
configuration the only wires that need to connect to the sensor module are power, ground, and Vout. In
this configuration the One-Wire digital communication line is connected to the Vout pin. When the
PGA309 is initially powered up, the Vout pin is placed in a high impedance mode for 15mS. If
communication is established using the One-Wire during this time, the PGA309 will keep Vout in high
impedance until the communications is complete. After the communication is complete the PGA309 Vout
pin will become active and remain active until power is cycled again. While using the EVM to
communicate in Three Wire Mode, the EVM will cycle power before each One-Wire communication.
