2

USING THE EVALUATION BOARD

To power up the SP6231 evaluation board, connect +5.0Vin (or use the USB connector)

to the Vin 5V post and GND located on the top right corner of the SP6231 evaluation

board. Connect +3.3V Auxiliary Power to the VAUX 3.3V post and GND pin near the

U2 IC. An alternative 3.3VAUX input to U2 is to use U1, the SP6641B DC/DC converter

located on the left side of the Board. The SP6641B boost converter can provide 3.3V

out from a Battery input of 1.0V @ 150mA or 2.0V @ 400mA for the 3.3VAUX (see

figure 3 for SP6641B maximum load current curve). Just connect the Battery voltage

input to the VBATT and GND posts.

The SHDN connector J1 can be used to enable or disable the SP6641B. If the

SP6641B is not used the wire jumper J2 can be removed and the VAUX 3.3V input

alone should be used. Low voltage start up voltage for the SP6641B is around 0.9V at

light load RL=3.0K

Ω.

Connect the Load to the pins Vout 3.3V and GND on the right side of the Board.

EVALUATION BOARD DATA

FIGURE 1. Vout for 500mA Load Step

Vin = 5V Supply

Ch1 = Vout (AC)

Ch4 = Iout 500mA/div

FIGURE 2. Switching: Vaux to Vin to Vaux

Vin = 5V, Vaux = 3.3V, Iout = 300mA

Ch1 = Vin

Ch2 = Vaux (AC)(SP6641B 3.3Vo, 2.6Vin)

Ch3 = Vout (AC)

Figure 3. SP6641B Maximum Load Current in Operation

0

50

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1.0

1.5

2.0

2.5

3.0

Vin (V)

Vin

Vaux

Vout

Vout

Iout