Datasheet

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2 Setup

2.1 Input / Output Connector Descriptions

2.2 Setup

Setup

If desired, converters 1 and 3 on this EVM can be easily modified to supply higher or lower output

voltages. The converter can be adjusted to provide an output voltage between 1.217 V and 6.34 V. Output

voltages other than the default values may be evaluated by adjusting the appropriate feedback resistors.

Also, other fixed output voltage versions of the devices can be easily evaluated using this EVM. Refer to

the TPS799xx data sheet (SBVS056 A) for the various fixed output voltage options available in the

TPS799xx device family as well as for more information on adjusting the output voltage.

This chapter describes the jumpers and connectors on the EVM as well as how to properly connect, setup,

and use the TPS799xxEVM-105.

J1, TP1 and TP3 – VIN — This is the positive input connection to the corresponding converter. The leads

to the input supply should be twisted and kept as short as possible to minimize EMI transmission.

J2, TP2 and TP4 – GND — This is the input return connection for the input power supply for the

corresponding converter

J3, TP5 and TP7 – VOUT — This is the positive connection from the output of the corresponding

converter. Connect this pin to the positive input of the load.

J6, TP6 and TP8 – GND — This is the return connection from the output of the corresponding converter.

Connect this pin to the negative input of the load.

JP1, JP2 and JP3 – EN — This jumper enables or disables the corresponding converter. Connect the

shorting jumper from the center EN pin to either the ON or OFF position. This pin should never be

left floating.

There are two different package styles on the TPS799xxEVM-105. The thermal performance of each

package style and ambient temperature may limit the input voltage or output current of the converters.

Since the converter outputs are set, the power dissipated in the package relates only to the input voltage

and output current. Table 2 shows the maximum input voltage at full load current of 200 mA. Above this

voltage, the output current must be reduced to keep the power dissipation of the package below the

maximums stated in the datasheet. Output voltage or ambient temperature changes affect these values.

Table 2 also shows the minimum input voltage required to produce an output for each converter. The

minimum input voltage is the output voltage plus the necessary dropout voltage.

Table 2. Minimum and Maximum Input Voltage

Minimum Input Max Input Voltage Before Current

Converter Output Voltage

Voltage Derate (T

= 25 ° C, I

= 200 mA)

1 1.6 1.775 3.4

2 2.8 2.975 4.7

3 3.3 3.46 5.1

For converters number 1 and 3, the user can replace the factory supplied TPS79901 with other fixed

voltage converters in the TPS799xx family. R1 and C5 should be removed and left open and a noise

reduction capacitor installed in place of R2 when using a fixed voltage IC in converter 1. R3 and C7

should be removed and left open and a noise reduction capacitor installed in place of R4 for converter 3

when using a fixed voltage IC.

TPS799xxEVM-105 2 SLVU130 – June 2005