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2A Synchronous
y
Step-Down
p
DC/DC Converters
New Product Release
XC9242/XC9243 Series
Digital
Camera
Mobile
Phone
Tablet PC
Bluetooth
Equipment
The XC9242/XC9243 series of step-down DC/DC converters support
ceramic capacitors, use a synchronous rectification circuit, and have an
output current of 2A. A 0.11㱅 (TYP.) P-channel MOS driver transistor and a
0.12㱅 (TYP.) N-channel MOS switch transistor are built in. By reducing the
on-resistance of the internal transistors, a stable voltage can be supplied
with high efficiency up to an output current of 2A. The output voltage can be
SOP-8FD
USP-10B
set as desired by connecting two external resistors to the FB pin.
(2.6㬍2.9㬍0.6mm) (6.0㬍4.9mm)
1
Reduced on-resistance in the same package
VIN=5.0V,VOUT=3.3V
fOSC=1.2MHz(XC9243),1.0MHz(XC9223)
2.0A support is possible!
2
A built-in switch type step-down DC/DC converter can now
support up to 2.0A with an input voltage of 6V or less.
100
Efficiency : EFFI(%)
95
VIN
90
85
XC9243
80
2.0A
6.0V
XC9223
75
XC9235
XC9236
70
XC9223
XC9224
XC9242/XC9243
65
60
2.7V
2.5V
1.8V
55
50
100
1000
10000
Output Current : IOUT(mA)
The XC9243 achieves high efficiency over a wide output current range through the
use of PWM/PFM auto switching control. Thanks to a lower on-resistance, the XC9243
exhibits a higher efficiency at higher current than the previous product (XC9223).
3
1.0A
2.0A
IOUT
Miniaturization is achieved!
XC9220/XC9221
(2.9㬍2.8mm)
䂓TYPICAL APPLICATION CIRCUIT
75䋦
Reduce
SOT-25
XC9242/XC9243
(2.6㬍2.9mm)
㪭㪦㪬㪫
㪣
㪩 㪝㪙㪈 㪚㪝㪙 㪚㪣
㪧㪞㪥㪛
USP-10B
SOT-89
㪣㫏
㪧㪞㪥㪛
SMA
㪩 㪝㪙㪉
㪝㪙
㪘㪞㪥㪛
㪣㫏
㪭㪠㪥
㪧㪭㪠㪥
㪚㪠㪥㪈
㪧㪭㪠㪥
㪘㪭㪠㪥
㪚㪜
㪚㪠㪥㪉
XP162A
XBS304
(4.5㬍4.0mm) (5.2㬍2.8mm)
In previous products, a P-ch power MOSFET and Schottky diode were necessary to achieve 2A output; however, these
switching functions are built into the XC9242/XC9243 to reduce the number of components and achieve miniaturization.
Features
Driver Transistor Built-In 0.11㱅 (TYP.) P-ch Driver Tr.
0.12㱅 (TYP.) N-ch Switching Tr.
2.7V䌾6.0V
Input Voltage Range
Maximum Duty Cycle
Function
䇭100䋦
Soft Start, CL Discharge
Thermal Shutdown
Output Voltage Setting
0.9V䌾VIN
FB Voltage
0.8V±2.0䋦
Capacitor
Ceramic Capacitor
High Efficiency
95䋦 (TYP.) (VIN=5.0V, VOUT=3.3V)
2.0A
Control Methods
PWM (XC9242)
PWM/PFM Auto(XC9243)
1.2MHz±15%, 2.4MHz±15%
Packages
USP-10B, SOP-8FD
Output Current
Oscillation Frequency
Current Limit Circuit 䋨Automatic Return䋩, UVLO
www.torex.co.jp/english/
August 2011㽳
䃂 Values shown in this sheet can be changed without any prior notice.
New Product Release
2A Synchronous Step-Down DC/DC Converters䇭XC9242/XC9243 Series
4
Automatic return vs. Latch
Device
DC/DC
Device
CL
㪪㫎㫀㫋㪺㪿
㪦㪥
IOUT
ON / OFF
Lx
㪪㫎㫀㫋㪺㪿
㪦㪝㪝
Latch
DC/DC
Time
C1
VOUT
VOUT
Device
C2
Time
Capacitance Load
When a DC/DC converter with a latch-type overcurrent protection
function is used in a circuit similar to that shown above and the circuit
switches ON/OFF, the charge that goes to the capacitors (C1 and C2)
becomes a large load and the output voltage drops suddenly. This may
cause the short circuit protection function to activate, or the current
limitation state may last longer than the latch time causing the latch
function to activate and stop operation.
When the XC9242/XC9243 is used in this type of situation, instead
of the latch function activating and causing operation to stop, restart is
automatically performed from the soft-start sequence without an external signal. This is convenient for restart by capacitor loads.
㪪㫎㫀㫋㪺㪿
㪦㪝㪝
XC9242
XC9243
㪪㫎㫀㫋㪺㪿
㪦㪥
IOUT
Time
VOUT
Time
5
Comparison of step-down synchronous DC/DC converter characteristics
䇼The optimum product can be selected for the current䇽
Maximum Output Current
Output Voltage
Input Voltage
Oscillation Frequency
Control
XC9242/XC9243
XC9235/XC9236/XC9237
2000mA
600mA
XC9223/XC9224
1000mA
0.9V䌾VIN can be set with
using externally connected resistors
0.8V䌾4.0V (0.05V Increments)
0.9V䌾VIN can be set with
using externally connected resistors
2.7V䌾6.0V
1.8V䌾6.0V
2.5V䌾6.0V
1.2MHz±15%
2.4MHz±15%
1.2MHz±15%
3MHz±15%
1MHz±15% 䋨Synchronous external clock䋩
2MHz±15% 䋨Synchronous external clock䋩
PWM䋺䋨XC9242䋩
PWM/PFM Auto䋺䋨XC9243䋩
PWM/PFM Auto
(With PWM Fixed Pin)䋺
䋨Both XC9223/XC9224䋩
PWM䋺䋨XC9235䋩
PWM/PFM Auto䋺䋨XC9236䋩
Manual䋺(XC9237)
High Side P-ch
ON Resistance
Low Side N-ch
ON Resistance
Supply Current
0.11Ω @ VIN=5.0V
0.35Ω @ VIN=5.0V
0.19Ω @ VIN=5.0V
0.11Ω @ VIN=5.0V
0.45Ω @ VIN=5.0V
0.21Ω @ VIN=5.0V
41㱘A (1.2MHz)
15㱘A (1.2MHz)
30㱘A (1MHz)
Package (mm)
USP-10B (2.9㬍2.6㬍0.6)
SOP-8FD (6.0㬍4.9)
SOT-25 (2.9㬍2.8)
USP-6C (1.8㬍2.0㬍0.6)
USP-6EL (1.8㬍2.0㬍0.4)
MSOP-10 (3.0㬍4.9)
USP-10B (2.9㬍2.6㬍0.6)
Function
䊶CE Function
䊶Current Limiter Circuit
䋨Constant Current & Automatic Return䋩
䊶Thermal Shutdown
䊶CL High Speed Discharge
䊶Soft Start
䊶CE Function
䊶Current Limiter Circuit
䋨Constant Current & Latching䋩
䊶CL High Speed Discharge
䊶High Speed Soft Start
䊶Synchronous External Clock
䊶CE Function
䊶Current limit binary switching selection
䋨Constant Current & Latching䋩
䊶Short-circuit Protection
䊶Thermal Shutdown
䊶Soft Start
䊶Voltage Detector
(This function is always on with the XC9224)
www.torex.co.jp/english/
August 2011㽳
䃂 Values shown in this sheet can be changed without any prior notice.