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MP1517 – 3A, 25V, 1.1MHz STEP-UP CONVERTER
MP1517 Rev. 1.4
4/28/2006
www.MonolithicPower.com
4
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
2006 MPS. All Rights Reserved.
TYPICAL PERFORMANCE CHARACTERISTICS
(continued)
4.8
4.6
4.4
4.2
4.0
3.8
3.6
3.4
3.2
3.0
C
TEMPERATURE (
°
C)
MP1517-TPC06
Current Limit vs
Temperature
2.43
2.42
2.41
2.40
2.39
2.38
2.37
2.36
B
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
Compensation: Error Amplifier Output. Connect to a series RC network to compensate
the regulator control loop.
No Connect
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.
Regulator On/Off Control Input. A logic high input (V
EN
> 1.5V) turns on the regulator, a
logic low puts it into low current shutdown mode.
The EN pin cannot be left floating.
Signal Ground
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.
Input Supply Pin. This pin can be connected to the regulator’s input supply or to the
output for boot-strapped operation.
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.
Power Ground
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.
Regulation Feedback Input. The regulation threshold is 0.7V.
1
COMP
2, 6, 14
NC
3
BP
4
EN
5, 13
7
SGND
OLS
8
IN
9, 10
SW
11, 12
PGND
15
SS
16
FB