UM_6612_044
78M6612 Split-Phase Evaluation Board User Manual
2.3 Optional UART Interface
The 78M6612 Split-Phase Evaluation Board provides an option to bypass the on-board serial USB
controller. This option is useful for communicating with an external controller or attachment of a wireless
module.
The optional UART interface is accessible via connector J12. Remove the 0Ω resistor R38 to prevent TX
contention with the on-board isolator’s output, U3.
UART Connector
J12
Remove R38
Figure 5: UART Connector
Due to the 78M6612’s V3P3 being directly connected to Neutral, the Teridian supplied
UART isolator must be inserted between the evaluation board and the external controller.
The V3P3 to Neutral connection results in the 78M6612’s GND pin being 3.3V below the
external controller’s GND pin. Additionally, the UART isolator board provides for galvanic
isolation between the evaluation board and the external controller hardware.
Installed
UART
Isolator
Short cable
harness to
external
Daughter Card
controller
Figure 6: UART Isolator Daughter Card
Rev. 1.1
11
TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
