LX7186A
1.4MHz, 1A Synchronous
Buck Converter
Features
Input Supply Range: 2.5V to 5.5V
Description
Output Adjustable from 0.6V to VIN 0.5V
The LX7186A is 1.4MHz fixed frequency, current-
100% Duty Cycle in Dropout
mode, synchronous PWM buck (step-down) DC-DC
Integrated NMOS & PMOS Switches
converter, capable of driving a 1A load with high
efficiency, excel lent line and load regulation. The Current Mode Control
device integrates synchronous P-channel and N-
1A Maximum Output Current
channel power MOSFET switches with low on-
Fixed 1.4MHz Frequency
resistance. They accept an input voltage range from
High Efficiency: Up To 96%
2.5V to 5.5V and will enter 100% duty cycle at
Built-in Soft-start
dropout making them ideal for powering portable
equipment that runs from a single Li-ion battery. Built-in UV & OT Protection
Built-in Short Circuit Protection
A standard series of inductors are available from
RoHS Compliant & Halogen Free
several different manufacturers optimized for use
with the LX7186A. This feature greatly simplifies the
TSOT-5L or UDFN 2x2 6L Packages
design of switch- mode power supplies.
The converter includes standard safety features
Applications
such as over-current, short-circuit and thermal
Datacom
shutdown protec tion. This device is available in
both TSOT-5L and UDFN 2x2 6L packages.
Portable Devices
Smart Phone
VIN
L 2.2H VOUT
1 (6)
5 (2)
VIN SW
CIN
4.7F
R1 COUT
22F
LX7186A
4 (3)
ON OFF
FB
3 (4)
EN
R2
GND
2 (1, 5)
TSOT-5L (UDFN 2x2 6L)
Figure 1 Typical Application of LX7186A
October 2013 Rev. 1.5 www.microsemi.com 1
2013 Microsemi Corporation 186A
YWWA
86A
1.4MHz 1A Synchronous Buck Converter
Pin Configuration and Pinout
1 6
1 5
VIN SW
GND
VIN
2 5
2
GND
SW GND
3 4
3 4
EN FB
FB EN
YWWA = bottom mark
Figure 2 Pinout TSOT-5 Top View Figure 3 Pinout UDFN 2x2 6L Top View
Marking: Front Mark 86A Marking: Line1 186A
Bottom Mark YWWA Line2 YWWA
Year/Work Week/Lot Code Year/Work Week/Lot Code
Ordering Information
Ambient
Type Package Part Number Packaging Type
Temperature
LX7186AISG Bulk / Tube
TSOT-5L
LX7186AISG-TR Tape and Reel
RoHS Compliant,
-40C to 85C
Pb-free
LX7186AILU Bulk / Tube
UDFN 2x2 6L
LX7186AILU-TR Tape and Reel
Pin Description
Pin Number
Pin Designator Description
TSOT-5L UDFN 2x2 6L
Supply Input Pin. A 4.7F ceramic capacitor should be connected
1 6 VIN
between the VIN pin and GND pin to bypass the supply.
2 1, 5 GND Ground Pin.
Enable Input. Setting this pin above 1.5V enables the IC. Setting this pin
3 4 EN below 0.4V shuts down the IC. When the IC is in shutdown mode, all
functions are disabled to decrease the supply current below 1A.
Feedback Pin. This pin is connected to an external resistor divider to
4 3 FB
program the system output voltage.
Power Switch Output Pin. Inductor connection to drain of the internal
5 2 SW
PFET and NFET switches.
2