EV0007

2A MP1580 Step Down

Switch Mode Converter

EVALUATION BOARD

Monolithic Power Systems

Figure 2: EV0007 Schematic

Sync

L1

5 V

R2E

R2A

RC

C1

U1

MP1580HS

1

2

3

4

5

6

7

8

BS

IN

SW

GND

FB

COMP

EN

SYNC

EN

J5

CC

R2D

R1

J3

VIN=4.75Vto 25V

CN2

1

2

3

4

1.8 V

C4

J6

1.22 V

CB

J1

3.3 V

2.5 V

CN1

1

2

3

4

J2

1.5 V

R2B

CCA

J4

D1

R2C

GND

VOUT

GND

Available Output Voltages (VOUT)

External

Power

Supply

- +

External

Load

Board Operation

This board is laid out to accommodate most commonly used Inductors and Output Capacitors and to

be programmed for most standard Output Voltages.

1)

Attach positive end of load to pin 1 = 2 and negative end of load to pin 3 = 4 of connector CN2.

2)

For the required output voltage (VOUT = 1.22, 1.5, 1.8, 2.5, 3.3 or 5V) solder blob the appropriate

J1 thru J6 jumper respectively.

3)

Attach input voltage (VIN) and input ground (GND) to Pin 1 and 2 of connector CN1 respectively.

Note VIN must be 4.75V < VIN < 25V.

4)

Pin 3 of CN1 is used to synchronize the internal oscillator frequency of the MP1580 to an external

source. The synchronization rate can be vary from 380KHZ (normal operation) to 600KHz. There

is an internal 11KΩ pull down resistor to GND therefore leave this pin unconnected if unused.

5)

Applying a voltage greater than 2.495V to pin 4 of CN1 enables the MP1580. Leave the input

unconnected if unused. An Under Voltage Lockout (UVLO) function can be implemented by the

addition of a resistor divider from VIN to GND. For complete low current shutdown its needs

to be less than 0.7V.

EV0007 Rev 1.5_08/14/02

www.monolithicpower.com

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