AN2471

Evaluation board

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1

Evaluation board

The STMAV335 evaluation board provides the customer with straightforward evaluation on

the performance and the typical use of the switch in the real system.

The boards include an STMAV335 switch, video input and output connectors, jumper for

setting the control lines status, and a power supply portion.

1.1

Power supply

The board can be powered either directly from a DC power supply or from a DC adaptor. If it

is powered from a DC power supply, 5VDC is connected to the power socket labeled

VCC5V and the ground is connected to the power socket labeled GND. The board can also

be powered from a DC adaptor having output voltage of 7 V to 15 V. The DC adaptor voltage

will be regulated to 5 V by the on-board regulator. The DC adaptor can be center positive or

negative and it should be connected to the DC JACK.

To prevent digital noise from coupling to the analog lines, the power distribution is separated

from digital and analog sections. Though STMAV335 has also two digital lines, which are

SEL1 and SEL2, it should still be powered from the analog supply. The reason is because its

main function is to switch analog signals and those two digital lines are mostly static during

operation. Hence the analog lines will not be disturbed by the digital part and as such, there

is no need to have a separate analog and digital supply for STMAV335.

The analog and digital sections on the board are isolated by ferrite beads.

Note:

External power can be applied to either VCC5V/GND or DC JACK, but not to both.

Table 1.

Power connector

Designator

Notes

VCC5V

Connect to 5 V of external power supply.

GND

Connect to ground of external power supply.

DC JACK

Connect to DC adaptor output if the board is to be

powered from DC adaptor.

Input Voltage: 7 to 15 V