XC9248
Series
18V Driver Transistor Built-In Synchronous Step-Down DC/DC Converter
ETR05022-004
■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
●Notebook
computers
●Car
accessories power supplies
■FEATURES
Input Voltage
Output Voltage
Output Current
Efficiency
Oscillation Frequency
Maximum Duty Cycle
Soft-Start Time
Protection Circuit
：
4.5V
½
18V
：
1.0V½12V (V
FB
=0.8V±1.5%)
：
2.2A
：
93.8%
：
79%
：
Fixed2.8ms, set by external capacitor
：
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
Environmentally Friendly
(*1)
(*1)
(*1)
@V
IN
=12V,V
OUT
=5V, I
OUT
=700mA
：
500kHz
：
SOP-8FD
：
EU RoHS Compliant, Pb Free
Performance depends on external components and wiring on the PCB.
■TYPICAL
APPLICATION CIRCUIT
■TYPICAL
PERFORMANCE
CHARACTERISTICS
Efficiency vs. Output Current
Ta=25°C
L
V
IN
EN
V
IN
EN
SS
FB
C
IN
C
SS
L
X
GND
BST
C
BST
C
FB
V
OUT
R
FB1
100
90
80
Efficiency [%]
70
60
50
40
30
20
10
0
0
500
1000
1500
Output Current : I
OUT
[mA]
V
IN
=12V , V
OUT
=3.3V
V
IN
=12V , V
OUT
=5V
V
L
C
VL
C
L
R
FB2
2000
1/21
TOREX [ TOREX SEMICONDUCTOR ]
