MP1542 MPS, MP1542 Datasheet - Page 5

• Manufacturer Part Number: MP1542
• Description: Monolithic Power Systems
• Manufacturer: MPS

PIN FUNCTIONS
OPERATION
The MP1542 uses a constant frequency, peak
current mode boost regulation architecture to
regulate the feedback voltage.
01/05, Rev. 1.0
Pin #
1
2
3
4
5
6
7
8
FSEL
COMP Compensation Pin. Connect a capacitor and resistor in series to ground for loop stability.
Name Description
EN
FSEL
SS
GND
SW
FB
EN
SS
IN
Feedback Input. Reference voltage is 1.25V. Connect a resistor divider to this pin.
Regulator On/Off Control Input. A high input at EN turns on the converter, and a low input turns
it off. When not used, connect EN to the input source (through a 100kΩ pull-up resistor if V
6V) for automatic startup. EN cannot be left floating.
Ground.
Power Switch Output. SW is the drain of the internal MOSFET switch. Connect the power
inductor and output rectifier to SW. SW can swing between GND and 25V.
Input Supply Pin. IN must be locally bypassed.
Frequency Select Pin. Tie to IN (through a 100kΩ resistor if V
GND for 700KHz operation.
Soft-Start Control Pin. Connect a soft-start capacitor to this pin. The soft-start capacitor is
charged with a constant current of 6µA.
OSCILLATOR
AND ENABLE CIRCUITRY
INTERNAL REGULATOR
MPS Proprietary Information. © 2005 All Rights Reserved.
MP1542 – 700KHz/1.3MHz BOOST CONVERTER WITH A 2A SWITCH
Figure 1—Functional Block Diagram
Unauthorized Photocopy and Duplication Prohibited.
+
--
IN
The
understood by referring to the block diagram of
Figure 1.
CONTROL
LOGIC
PWM
operation
CURRENT
SENSE
GM
AMP
--
+
IN
1.25V
> 6V) for 1.3MHz operation or to
of
+
--
the
MP1542
INITIAL RELEASE
MP1542_BD01
SW
GND
FB
COMP
can
IN
>
be
5