XC9243B08CDR-G Datasheet, PDF (1/29 Pages) Torex Semiconductor – 2A Synchronous Step-Down DC/DC Converters

XC9242/XC9243 Series
ETR0521-010
2A Synchronous Step-Down DC/DC Converters
ˑGreenOperationçCompatible
˙GENERAL DESCRIPTION
The XC9242/XC9243 series is a group of synchronous-rectification step-down DC/DC converters with a built-in 0.11Њ
(TYP.) P-channel MOS driver transistor and 0.12Њ(TYP.) N-channel MOS switching transistor, designed to allow the use of
ceramic capacitors. The small on-resistances of these two internal driver transistors enable a high efficiency, stable power
supply with an output current up to 2A. The XC9242/XC9243 series has operating voltage range of 2.7V~6.0V and a 0.8V
(±2.0%) reference voltage, and using externally connected resistors, the output voltage can be set freely from 0.9V. With
an internal switching frequency of 1.2MHz or 2.4MHz, small external components can be used.
The XC9242 series is PWM control, and the XC9243 series is PWM/PFM, which automatically switches from PWM to PFM
during light loads and provides high efficiency, high load response, low voltage ripple, can be achieved over a wide range of
load conditions. The series have a high speed soft-start as fast as 1ms in typical for quick turn-on. It’s suitable for
large-current application due to limit current is configured 4.0A in typical. During stand-by, all circuits are shutdown to
reduce current consumption to as low as 1.0ЖA or less. The integrated C_L discharge function which enables the electric
charge at the output capacitor C_L to be discharged via the internal discharge switch located between the L_X and V_SS pins.
Due to C_L discharge function, malfunction on L_X is prevented when Stand-by mode. With the built-in UVLO (Under Voltage
Lock Out) function, the internal P-channel driver transistor is forced OFF when input voltage becomes 2.5V or lower. The
series are available in USP-10B, SOP-8FD packages.
˙APPLICATIONS
˙FEATURES
Driver Transistor
: 0.11Ω P-ch Driver Transistor
˔ç Mobile phones
˔ç Bluetooth headsets
˔ç Personal digital assistance
˔ç Portable game consoles
˔ç Digital still cameras, Camcorders
Input Voltage Range
Output Voltage Setting
FB Voltage
High Efficiency
Output Current
0.12Ω N-ch Switching Transistor
: 2.7V～6.0V
: 0.9V～V_IN
: 0.8V±2.0%
: 95%(TYP.)*
: 2.0A
Oscillation Frequency
: 1.2MHz±15%, 2.4MHz±15%
Maximum Duty Cycle
: 100%
Functions
: Soft-Start Circuit Built-In
C_L Discharge
Current Limit Circuit（automatic return）
Thermal Shutdown
UVLO
Output Capacitor
: Low ESR Ceramic Capacitor
Control Methods
: PWM control (XC9242)
PWM/PFM Auto (XC9243)
Operating Ambient Temperature : -40℃ ~ +85℃
Packages
: USP-10B, SOP-8FD
Environmentally Friendly
: EU RoHS Compliant, Pb Free
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* Performance depends on external components and wiring on the PCB.
˙TYPICAL APPLICATION CIRCUIT
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˔XC9242/XC9243 Series (FB Type)
˙TYPICAL PERFORMANCE
CHARACTERISTICS
˔Efficiency vs. Output Current (fosc=1.2MHz, V_OUT=3.3V)
100
90
80
70
60
50
40
30
20
10
0
0.1
XC9242B08C
L=4.7μH(SLF7055),CIN1=20μF(LMK212ABJ106KGx2)
CIN2=1μF(LMK107BJ105KAx1),CL=20μF(LMK212ABJ106KGx2)
RFB1=47kΩ, RFB2=15kΩ, CFB=330pF
V_IN=5.0V
1
10 100 1000 10000
Output Current: I_OUT (mA)
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