MP2104 MPS, MP2104 Datasheet - Page 6

• Manufacturer Part Number: MP2104
• Description: 1.7mhz, 600ma Synchronous Step-down Converter
• Manufacturer: MPS

PIN FUNCTIONS
OPERATION
The MP2104 is a constant frequency current
mode PWM step-down converter. The MP2104
is optimized for low voltage, Li-Ion battery
powered applications where high efficiency and
small size are critical. The MP2104 uses an
external resistor divider to set the output
voltage from 0.6V to 6V. The device integrates
both a main switch and a synchronous rectifier,
which provides high efficiency and eliminates
MP2104 Rev. 1.4
5/28/2008
TSOT23-5
Pin #
1
2
3
4
5
5
TQFN-6
Pin #
2, 6
3
1
5
4
–
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
Exposed Pad
Name
GND
OUT
MP2104 – 1.7MHz 600mA SYNCHRONOUS STEP-DOWN CONVERTER
SW
EN
FB
IN
Description
Regulator Enable Control Input. Drive EN above 1.5V to turn on the
MP2104. Drive EN below 0.3V to turn it off (shutdown current < 0.1µA).
Ground. Connect exposed pad (MP2104DQT) to GND plane for proper
thermal performance.
Power Switch Output. Inductor connection to drains of the internal
PFET and NFET switches.
Supply Input. Bypass to GND with a 2.2µF or greater ceramic
capacitor.
Feedback Input (MP2104DJ and MP2104DQT). Connect FB to the
center point of the external resistor divider. The feedback threshold
voltage is 0.6V.
Output Voltage Sense Input (MP2104DJ-1.5 and MP2104DJ-1.8). An
internal resistor divider is connected to this pin to set the proper output
voltage.
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www.MonolithicPower.com
an external Schottky diode. The MP2104 can
achieve 100% duty cycle. The duty cycle D of a
step-down converter is defined as:
Where T
the oscillator frequency (1.7MHz), V
output voltage and V
D
=
ON
T
ON
is the main switch on time, f
×
f
OSC
×
IN
100
is the input voltage.
%
≈
V
V
OUT
IN
×
100
OUT
%
is the
OSC
is
6