MP1517 – 3A, 25V, 1.1MHz STEP-UP CONVERTER

MP1517 Rev. 1.4

www.MonolithicPower.com

4

4/28/2006

MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.

© 2006 MPS. All Rights Reserved.

4.8

4.6

4.4

4.2

4.0

3.8

3.6

3.4

3.2

3.0

TEMPERATURE (

°C)

MP1517-TPC06

Current Limit vs

Temperature

2.43

2.42

2.41

2.40

2.39

2.38

2.37

2.36

TEMPERATURE (

°C)

MP1517-TPC05

BP Voltage vs

Temperature

940

920

900

880

860

840

820

-50

0

50

100

150

TEMPERATURE (

°C)

MP1517-TPC04

Operating Supply

Current vs Temperature

-50

0

50

100

150

-50

0

50

100

150

PIN FUNCTIONS

Pin #

Name

Description

1

COMP

Compensation: Error Amplifier Output. Connect to a series RC network to compensate

the regulator control loop.

2, 6, 14

NC

No Connect

3

BP

Output of the Internal 2.4V Low Dropout Regulator. Connect a 10nF bypass capacitor

between BP and SGND. Do not apply an external load to BP.

4

EN

logic low puts it into low current shutdown mode. The EN pin cannot be left floating.

5, 13

SGND

Signal Ground

7

OLS

Open Load Shutdown Pin. OLS senses regulator output voltage to protect IC during

open load operation. When this pin’s voltage exceeds 27V, the output switch is shut off.

The device then restarts in soft-start mode until it is disabled.

8

IN

Input Supply Pin. This pin can be connected to the regulator’s input supply or to the

output for boot-strapped operation.

9, 10

SW

Output Switch Node. SW is the drain of the internal N-Channel MOSFET. Connect the

inductor and rectifier to SW to complete the step-up converter.

11, 12

PGND

Power Ground

15

SS

Soft-Start Input. Connect a 10nF to 22nF capacitor from SS to SGND to set the soft-start

time. SS sources 2µA to an external soft-start capacitor during startup. As the voltage at

SS increases to 0.55V, the voltage at COMP is clamped to 0.7V above the voltage at SS

limiting the startup current. The external capacitor at SS is discharged to ground when

under voltage lockout, thermal shutdown occurs or open load shutdown occurs.

16

FB

Regulation Feedback Input. The regulation threshold is 0.7V.