DESCRIPTION

The SP6644/6645 Evaluation Board is designed to help the user evaluate the performance of

the SP6644/6645 for use as a single or dual cell input to +3.3V output DC-DC Converter. The

output of the SP6644/6645 is preset to +3.3V or can be adjusted from +2V to +5.5V by

manipulating two external resistors. The SP6644/6645UEB evaluation board is a complete

power supply circuit with an option for adding a small SOT23 5-pin +3V LDO Regulator to

provide even better regulation and low noise output.

The evaluation board is a completely assembled and tested surface mount board which

provides easy probe access points to all SP6644/6645 Inputs and Outputs so that the user can

quickly connect and measure electrical characteristics and waveforms.

The next two sections describe the SP6644/6645 Board Layout and Using the SP6644/6645

Evaluation Boards. Power Supply Data is supplied as measured from a typical SP6644/6645

evaluation board. The SP6644/6645 Evaluation Board List of Materials table is provided with

some manufacturers part numbers to use as a reference. Finally, a schematic and drawings of

the PC Layout are included as a design-in tool for the user of the SP6644/6645.

BOARD LAYOUT

The SP6644/6645 Evaluation Board has been designed for easy and convenient access to all

Inputs and Outputs of the SP6644/6645 device under test. Position the board with the

silkscreen lettering upright, (also see the drawing on the front page of this manual) and you will

see U1 the SP6644/6645 8-pin

µSOIC, in the center left of the board. To the left of U1 are the

input capacitor C1 and the Vbatt pin. To the right of U1 are the output capacitor C2 and the

Vout post. Above U1 is the inductor L1 and the LX test point.

Easy Evaluation for the

SP6644/6645 Single or Dual

Cell Alkaline to 3.3V Output

Provides up to 150mA output

current for 2-Cell Input

High Efficiency: 92%

µSOIC Package & SMT

components for small, low

profile Power Supply

SP6644/6645

Evaluation Board Manual