4A Step-Down Regulator
LX7180A
Description
The LX7180A is a 4A step-down regulator with
integrated MOSFETs packaged in a space saving
QFN12 2 mm x 2 mm for today’s mobile devices. It uses
an ultra-fast, constant frequency hysteretic control
method to minimize external filter components while
maintaining excellent regulation. The LX7180A reference
voltage is programmable from 0.6 V to 1.195 V through a
high speed (up to 3.4 MHz), bi-directional I2C bus.
The LX7180 operates from 3 V to 5.5 V rails and outputs
0.6 V to 100% of the input voltage.
Cycle-by-cycle current limiting protects against over-
current conditions. Hiccup mode provides protection for
heavy over-load or short-circuit faults. Thermal
protection shuts down the regulator under over-
temperature conditions. Over voltage conditions will
immediately shut off the output to protect against
permanent damage. The LX7180A automatically restarts
when all fault conditions are cleared.
Features
0-4 A Step-down Regulator
Operational Input Supply Voltage Range:
3.0 V - 5.5 V (short durations to 6.5 V)
Hysteretic Control Offers Best Transient Response
PWM Switching at a Constant 1.65 MHz
Power Save Mode (PSM) can be Selected to
Improve Light Load Efficiency.
100% Duty Ratio Operation
Input Under Voltage and Over Voltage Protection
Enable and Power Good Function
I2C Serial Interface at 3.4 Mbps
Internal Soft-start
Cycle-by-Cycle Over Current Protection
Hiccup Mode Protects Against Short Circuit Faults
Seven Bit Adjustable Reference Voltage via I2C Bus
RoHS Compliant
Applications
High Performance HDD
LCD TV
Notebook/Netbook
Server and Workstations
Video Cards
PoE Powered Devices Smart Phone
VIN
GND
SW
1, 10
PVIN
2, 11 0.47 µH
SW
10 µF 10 µF
X5R X5R
8 EN
LX7180A
FB 7
500 k
PGOOD
9 PG
PGND
3, 12
SCL 5
SDA 6
AGND
4
June 2015 Rev. 1.2
Figure 1 · Typical Application of LX7180A
www.microsemi.com
© 2015 Microsemi Corporation
VOUT
22 µF,
X5R
GND
1
