EV2109DQ-00A – DUAL 800mA, 6V, 1.2MHz SYNCHRONOUS STEP-DOWN CONVERTER

EVALUATION BOARD

NOTICE:

The information in this document is subject to change without notice. Please contact MPS for current specifications.

Users should warrant and guarantee that third party Intellectual Property rights are not infringed upon when integrating MPS

products into any application. MPS will not assume any legal responsibility for any said applications.

EV2109DQ-00A Rev. 1.1

www.MonolithicPower.com

4

10/14/2005

MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.

© 2005 MPS. All Rights Reserved.

TM

QUICK START GUIDE

The output voltages of this board are set to 1.8V (VOUT1) and 1.2V (VOUT2). The board layout

accommodates most commonly used inductors and output capacitors.

1. Attach the positive and negative ends of the first load to the VOUT1 and GND pins, respectively.

If using both outputs, attach the positive and negative ends of the second load to the VOUT2

and GND pins, respectively.

2. Attach the input voltage 2.5V

3. A 100kΩ pull-up resistor has been connected to both the EN1 and EN2 pins, so both VOUT1

and VOUT2 will turn on without applying any external voltage to the EN1 and EN2 pins.

4. To turn on VOUT1/VOUT2 by using the EN1/EN2 functions, apply a voltage, 1.5V

EN1/EN2 pin.

Calculate the new values by the following formulae:

1

V

V

1

R

2

R

FB

1

OUT

−

⎟⎟

⎠

⎞

⎜⎜

⎝

⎛

=

1

V

V

3

R

4

R

FB

2

OUT

−

⎟⎟

⎠

⎞

⎜⎜

⎝

⎛

=

Example:

Ω

=

−

⎟

⎠

⎞

⎜

⎝

⎛

Ω

=

k

150

1

V

6

.

0

V

8

.

1

k

300

2

R

Therefore, use a 150kΩ standard 1% value.