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Setup

1.6.2

Power Supply (*Optional)

To ensure correct functionality of the LEDs a 5V supply at 300mA is recommended (refer to note in

section 2.3.1). If not using a USB cable to power the LaunchPad a 3.3V power supply at 200mA is

required.

2

Setup

This section describes the jumpers and connectors on the EVM.

2.1

Connectors and Jumpers

2.1.1

J1

& J2 – LaunchPad Headers

These connectors mate with the male headers on the LaunchPad.

2.1.2

J3

– External LED Power

This connector is where the external +5V supply is attached to power the two RGB LEDs.

2.1.3

J4

– TCA7408 GPIO

This is a pin out of the four unused GPIO pins from the TCA7408, GPIO4-GPIO7.

2.1.4

J5

– Feedback loop

For the TPL0401A to function as a voltage reference circuit the negative feedback loop must be shorted,

placing a jumper across this header will short the inverting input to the output.

2.1.5

J6

– LED or Op-amp

This header controls what the TPL0401B is attached to. When shorted across position 1 and 2 the

TPL0401B is connected in series with the external resistor to control the current through the LED driver.

When shorted across position 2 and 3 the TPL0401B is connected to the inverting input of the op-amp to

change the gain of the circuit.

2.1.6

J7

– Op-amp input

This header controls the input to the non-inverting pin of the LMV321. When shorted across position 1 and

2, the TPL0401A in a voltage divider mode is attached to the non-inverting input of the LVM321. This

setup is used to test the voltage reference setup. When shorted across pins 2 and 3, the SMA connector

is attached to the non-inverting input.

2.1.7

J9

– Test Points

This connector offers test points for the serial data lines, SDA, SCL and the DIN that drives the TCA5405.

Table 1. Description of Connectors and Jumpers

Label

Description

J1, J2

Connectors to interface with LaunchPad

J3

External 5V for LED

J4

GPIO4-GPIO7 from TCA7408

J5

Control jumper to short feedback loop

J6

Jumper to control LED or Op-Amp

J7

Jumper to control input to Op-Amp

J8

SMA/B Footprint for external input

J9

Test points for DIN, SDA and SCL

3

SCPU034

– December 2011

TCA7408EVM,TCA5405EVM

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