Teridian 73S1217F, User Manual, Page: 30 / 34

73S1217F Evaluation Board User’s Guide UG_1217F_040
30 Rev. 2.4
4.6.3 LCD
The 73S1217F does not contain an on-chip LCD controller. However, an LCD module (with built-in
controller) can be used with the 73S1217F via use of specific USR (GPIO) pins. The LCD API libraries
support up to a 2 line/16 character display.
Figure 8 shows the basic connection for this type of LCD. The
LCD module must connect to the USR pins as shown and it requires an external brightness adjust circuit.
Figure 16: LCD Connections
4.6.4 USB Interface
The USB interface on the 73S1217F requires few external components for proper operation. Two serial
resistors of 24
Ω
± 1% are needed to provide proper impedance matching for the USB data signals D+
and D-.
For self-powered USB applications, a connection must be made between the VBUS power input and
USR7 for proper operation with the provided API libraries. A direct connection cannot be made as the
VBUS voltage exceeds the digital power supply running at 3.3 V. As a result, a resistor divider is required
to scale the VBUS voltage down to 3.3 V.
Figure 9 shows the basic USB connections.
Figure 17: USB Connections
73S1217F
73S1217F