XC9223/XC9224Series
ETR0509_007
1A Driver Transistor Built-In Step-Down DC/DC Converters
☆GreenOperation-Compatible
■GENERAL DESCRIPTION
The XC9223/XC9224 series are synchronous step-down DC/DC converters with a 0.21Ω (TYP.) P-channel driver transistor and a
synchronous 0.23Ω (TYP.) N-channel switching transistor built-in. A highly efficient and stable current can be supplied up to 1.0A by
reducing ON resistance of the built-in transistor. With a high switching frequency of 1.0MHz or 2.0MHz, a small inductor is selectable;
therefore, the XC9223/XC9224 series are ideally suited to applications with height limitation such as HDD or space-saving
applications. Current limit value can be chosen either 1.2A (MIN.) when the LIM pin is high level, or 0.6A (MIN.) when the LIM pin is
low level for using the power supply which current limit value differs such as USB or AC adapter. With the MODE/SYNC pin, the
XC9223/XC9224 series provide mode selection of the fixed PWM control or automatically switching current limit PFM/PWM control.
As for preventing unwanted switching noise, the XC9223/XC9224 series can be synchronized with an external clock signal within the
range of ± 25% toward an internal clock signal via the MODE/SYNC pin. For protection against heat damage of the ICs, the
XC9223/XC9224 series build in three protection functions: integral latch protection, thermal shutdown, and short-circuit protection.
With the built-in U.V.L.O. (Under Voltage Lock Out) function, the internal P-channel driver transistor is forced OFF when input voltage
becomes 1.8V or lower. The XC9223B/XC9224B series’ detector function monitors the discretional voltage by external resistors.
■APPLICATIONS
●HDD
■FEATURES
Input Voltage Range
: 2.5V ~ 6.0V
Output Voltage Range : 0.9V ~ VIN (set by FB pin)
Oscillation Frequency : 1MHz, 2MHz (+15% accuracy)
●Notebook computers
Output Current
Maximum Current
Limit
: 1.0A
●CD-R / RW, DVD
: 0.6A (MIN.) ~ 0.9A (MAX)
with LIM pin=’L’
: 1.2A (MIN.) ~ 2.0A (MAX.)
with LIM pin=’H’
: PWM/PFM or PWM by MODE pin
: Thermal shutdown
Integral latch method
●PDAs, Portable communication modems
●Digital cameras, Video recorders
●Various general-purpose power supplies
Controls
Protection Circuits
Short-circuit protection
: 1ms (TYP.) internally set
: B type (with VD function)
D type (without VD function)
: 0.21Ω
Soft-Start Time
Voltage Detector
Built-in P-channel
MOSFET
Built-in Synchronous
N-channel MOSFET
High Efficiency
: 0.23Ω
(No Schottky Barrier Diode Required)
: 95% (VIN=5.0V, VOUT=3.3V)
Synchronized with an External Clock Signal
Ceramic Capacitor Compatible
Packages
: MSOP-10, USP-10B, SOP-8
* SOP-8 package is available for the XC9223D type only.
■TYPICAL PERFORMANCE
CHARACTERISTICS
●Efficiency vs. Output Current
■TYPICAL APPLICATION CIRCUIT
XC9223B081Ax
XC9223B081Ax
VIN=5V, FOSC=1MHz, L=4.7uH(CDRH4D28C),
L=4.7μH (CDRH4D28C), CIN=10μF (ceramic), CL=10μF (ceramic)
CIN=10uF(ceramic), CL=10uF(ceramic)
VIN=5V, FOSC=1MHz,
100
90
80
70
60
50
40
30
20
10
0
VOUT=3.3V
VOUT=1.5V
(*1) A capacitor of 2200pF~0.1μF is recommended to place at the CDD between the AGND
pin and the VIN pin.
PWM/PFM
PWM
Please refer to the page showing INSTRUCTION ON PATTERN LAYOUT for more detail.
1
10
100
1000
Output Current: IOUT (mA)
1/25