
4.5 V to 24 A Adaptive Constant On V, 8
Time (COT) Synchronous Buck Regulator
Adaptive COT Control
Adjustable, Constant Switching Frequency
up to 1 MHz
Extremely Low- -MOSFETs RDSON N
Bus Voltage 4.5 V to 24 V
Selectable Diode Emulation Mode (PSM
Mode)
Current Limit, UVLO, OVP
Gate Resistor Provision for EMI Reduction
-40°C to +85°C Ambient Temperature
-40°C to +150°C Junction Temperature
RoHS Compliant
5×5 mm Very Thin Profile QFN (VQFN)
Package
Applications
Ultramobile/Notebook PCs
Tablets/Slates
-Hand held Portable Instruments
ADSL Modem
The NX9548 is a synchronous buck switching regulator
with 21 mΩ internal N-
channel MOSFETs, primarily
intended for portable (mobile) applications. The
NX9548 operates from 4.5 V to 24 V, and the output
voltage range is from 0.75 V, with output currents V to 5
as high as 8
A. It can be selected to operate in
synchronous mode, or non-
synchronous (diode
emulation or PSM) mode at light loads, to improve
Adaptive constant on time (COT) control provides
extremely fast transient response to line and load steps,
while at the same time providing near-constant
switching
frequency over a wide input voltage range.
The frequency is also externally adjustable.
The NX9548 features overcurrent protection (OCP),
voltage lockout (FB UVLO), and
overvoltage protection (OVP). It also includes an
integrated bootstrap Schottky diode, and provides low -
voltage (5 -V) gate
drive capability. In addition it
provides a Power Good indicator and has adaptive dead
time.
July 2015 Rev. 1.2 www.microsemi.com 1
© 2015 Microsemi Corporation