STR720-EVAL

2 Hardware

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2.7

Power supplies

Power to the board is supplied using a lump in cord power supply providing 5 V to the board. All

other required voltages are provided on-board by voltage regulators or voltage convertors.

2.8

USB full speed interface

USB full speed interface device supported by a type B connector. The USB clock uses a

separate 48 MHz oscillator. See

Section 3.1: USB on page 14.

2.9

CAN interface

A general purpose, asynchronous serial I/O data port connected through a 9-pin D-type male

connector with microswitch selectable low speed fault tolerant transceiver (L9669) or low or

high speed selectable transceiver (L9616). See

Section 3.2: CAN bus connector on page 14.

The L9669 transceiver only works in normal mode, the wake-up functionality is not

implemented.

Caution:

The board schematic for the CAN interface detailed in

Section 4.10: STR720-Eval board - CAN

interface, is not a reference design and should not be copied. To design a CAN interface with

the STR720 please refer to the “STR720 Hardware Development Getting Started Guide

AN1907”.

2.10

RS232 serial interfaces

Two general purpose, asynchronous serial I/O data ports are connected through 9-pin D-type

male connectors. Refer to

Section 3.3: RS232 serial data connector on page 15.

RS232-A connects directly to UART1, transmit and receive only. RS232-B connects to UART2,

transmit and receive only.

RTS is shorted to CTS and DTR is shorted to DSR at the connector for both interfaces.

2.11

Analog input

The following analog inputs are provided, see the schematics

Section 4.1 on page 18:

●

ADC connector: CN4,

●

LM35 temperature sensor IC4 is connected to pin 4 of the ADC connector CN4 (pins 3 and

4 must be shorted to enable temperature sensing,)

●

variable resistor VR1 is connected to pin 2 of the ADC connector CN4 (pins 1 and 2 must

be shorted to enable the variable resistor.)