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XC9248 Series
18V Driver Transistor Built-In Synchronous Step-Down DC/DC Converter
■GENERAL DESCRIPTION
The XC9248 series is 18V bootstrap synchronous step-down DC/DC converter with built-in Nch-Nch driver transistors.
With an input voltage range from 4.5V to 18V and a maximum output current of 2.2A, the series is suitable for digital home
appliance power supplies and can be used with small ceramic capacitors.
The series has a 0.8V reference voltage, and using externally connected resistors, the output voltage can be set freely from
1.0V to 12V.
The control method is synchronous PWM (Source/ Sink). The soft start time is internally set to 2.8ms (TYP.), also can be
adjusted using external capacitor.
With UVLO (Under Voltage Lock Out) function, the internal driver transistors are forced OFF when input voltage falls down
below 3.8V (TYP.).
The series includes over current protection, V
OUT
short-circuit protection, Lx short-circuit protection, V
OUT
overvoltage
protection and thermal shutdown.
■APPLICATIONS
●Digital home appliance
●Office automation equipment
●Note PCs / Tablet PCs
●Car accessories power supplies
■TYPICAL APPLICATION CIRCUIT
ETR05022-005
■FEATURES
Input Voltage
： 4.5V ∼ 18V
Output Voltage
： 1.0V∼12V (V
FB
=0.8V±1.5%)
(*1)
Output Current
：
2.2A
Efficiency
：
93.8%
(*1)
@V
IN
=12V,V
OUT
=5V, I
OUT
=700mA
Oscillation Frequency
：
500kHz
Maximum Duty Cycle
：
79%
Soft-Start Time
：
Fixed2.8ms, set by external capacitor
Protection Circuit
：
UVLO
High side over current protection
Low side over current protection
V
OUT
Short-circuit Protection
L
X
Short-circuit Protection
V
OUT
Over voltage protection
Thermal shutdown
Package
：
SOP-8FD
Environmentally Friendly
：
EU RoHS Compliant, Pb Free
(*1)
Performance depends on external components and wiring on the PCB.
Efficiency vs. Output Current
■TYPICAL PERFORMANCE
CHARACTERISTICS
L
V
OUT
V
IN
EN
C
SS
C
IN
C
BST
C
VL
C
L
C
FB
R
FB1
R
FB2
V
IN
EN
SS
FB
L
X
GND
BST
V
L
Ta=25°C
0
10
20
30
40
50
60
70
80
90
100
0 500 1000 1500 2000
Output Current : I
OUT
[mA]
Efficiency [%]
V
IN
=12V , V
OUT
=3.3V
V
IN
=12V , V
OUT
=5V
