XC9223_04 Datasheet, PDF (1/7 Pages) Torex Semiconductor – 1A Driver Transistor Built-In Step-Down DC/DC Converters

XC9223/9224 Series
1A Driver Transistor Built-In Step-Down DC/DC Converters
Preliminary
Step-Down DC/DC Converters
Built-in P-channel MOSFET
: 0.23Ω
Built-in Synchronous N-channel MOSFET : 0.25Ω
(No Schottky Barrier Diode Required)
High Efficiency
: 94% (VIN=5.0V, VOUT=3.3V)
Oscillation Frequency: : 1.0MHz, 2.0MHz
(Small Inductor for High Frequency Selectable)
Synchronized with an External Clock Signal
Ceramic Capacitor Compatible
MSOP-10 / USP-10 Packages
APPLICATIONS
HDD
October 7, 2004 V2
Green Operation Compatible
Notebook computers
CD-R / RW, DVD
PDAs, Portable communication modems
Digital cameras, Video recorders
Various general-purpose power supplies
GENERAL DESCRIPTION
The XC9223/9224 series are synchronous step-down DC/DC converters
with a 0.23Ω (TYP.) P-channel driver transistor and a synchronous
0.25Ω (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 XC9223/9224 series are ideally suited to
applications with height limitation such as HDD or space-saving
applications.
Current limit value can be chosen either 1.5A (MIN.) when the LIM pin is
high level, or 0.5A (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 XC9223/9224 series provide mode selection of
the fixed PWM control or automatically switching current limit PFM/PWM
control. As for preventing unwanted switching noise, the XC9223/9224
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 XC9223/9224 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 series’ detector function monitors the discretional voltage by external
resistors.
FEATURES
Input Voltage Range
Output Voltage Range
Oscillation Frequency
Output Current
Maximum Current Limit
Controls
Protection Circuits
Soft-Start Time
Voltage Detector
: 2.2V ~ 6.0V
: 0.8V ~ VIN
Can be set freely with 0.8V (+2%) of
reference voltage by the external resistors.
: 1MHz, 2MHz ( ± 15% accuracy)
: 1.0A
: 0.5A (MIN.) when LIM pin=’L’
: 1.5A (MIN.) when LIM pin=’H’
: PWM/PFM externally switching
: Synchronized with an external clock signal
: Thermal shutdown
: Integral latch method (over current limit)
: Short-circuit protection
: 3mS (TYP.) internally set
: 0.712V detect, N-ch open drain output
TYPICAL APPLICATION CIRCUIT
CIN
VIN
VDIN
VDOUT
1 VIN
2 VDIN
3 ^AGND
4 VDOUT
5 FB
PGND ₁₀
LX 9
CE 8
MODE/
SYNC
7
LIM 6
L
CE
MODE/SYNC
LIM
CFB
RFB1
RFB2
VOUT
CL
(ceramic)
TYPICAL PERFOMANCE CHARACTERICSTICS
Efficiency vs. Output Current
VIN=5.0V, FOSC=2.0MHz
L=2.0µH(CDRH4D28C), CIN=10µF(ceramic), CL=10µF(ceramic)
100
90
80
70
60
VOUT=3.3V
50
40
VOUT=1.5V
30
20
10
Output Current: IOUT (mA)
0
1
10
100
1000
10000
Data Sheet
1
DC000019