MP2363DN Monolithic Power Systems, MP2363DN Datasheet - Page 5

• Manufacturer Part Number: MP2363DN
• Description: 3A, 27V, 365khz Step-down Converter
• Manufacturer: Monolithic Power Systems

OPERATION
The MP2363 is a current-mode step-down
regulator. It regulates an input voltage between
4.75V to 27V down to an output voltage as low as
0.92V, and is able to supply up to 3A of load
current.
The MP2363 uses current-mode control to
regulate the output voltage. The output voltage
is measured at the FB pin through a resistive
voltage divider and amplified through the internal
error amplifier. The output current of the
transconductance error amplifier is presented at
COMP where a network compensates the
regulation control system. The voltage at COMP
is compared to the switch current measured
internally to control the output voltage.
MP2363 Rev. 1.0
6/15/2006
EN 7
IN 2
COMPARATOR
FREQUENCY
2.54V/
2.33V
FOLDBACK
1.2V
+
--
--
+
COMPARATOR
COMPARATOR
SHUTDOWN
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
REGULATORS
LOCKOUT
+
--
INTERNAL
0.35V
OSCILLATOR
Figure 1—Functional Block Diagram
5
365KHz
35KHz/
0.92V
FB
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www.MonolithicPower.com
SS 8
SLOPE
COMP
CLK
MP2363 – 3A, 27V, 365KHz STEP-DOWN CONVERTER
--
+
AMPLIFIER
CURRENT
+
--
AMPLIFIER
SENSE
The converter uses an internal N-Channel
MOSFET switch to step-down the input voltage
to the regulated output voltage. Since the
MOSFET requires a gate voltage greater than
the input voltage, a boost capacitor connected
between SW and BS drives the gate. The
capacitor is charged by an internal 5V supply
while SW is low.
An internal 10Ω switch from SW to GND is used
to insure that SW is pulled to GND when SW is
low
ERROR
COMPARATOR
CURRENT
to
6
S
R
fully
COMP
+
--
Q
Q
1.8V
charge
the
boost.capacitor.
5V
1
3
4
BS
SW
GND
5