Document
XC9235/XC9236/XC9237 Series
ETR05014-017a
600mA Driver Tr. Built-In, Synchronous Step-Down DC/DC Converters
■GENERAL DESCRIPTION
☆Green Operation Compatible
The XC9235/XC9236/XC9237 series is a group of synchronous-rectification type DC/DC ☆coGnvreeertneOrspweritahtiaonbuCilot-minp0a.4tib2Ωle Pchannel MOS driver transistor and 0.52Ω N-channel MOS switching transistor, designed to allow the use of ceramic capacitors. Operating voltage range is from 2.0V to 6.0V (A~C types), 1.8V to 6.0V (D~G types). For the D/F types which have a reference voltage of 0.8V (accuracy:±2.0%), the output voltage can be set from 0.9V by using two external resistors. The A/B/C/E/G types
have a fixed output voltage from 0.8V to 4.0V in increments of 0.05V (accuracy:±2.0%). The device provides a high efficiency, stable power supply with an output current of 600mA to be configured using only a coil and two capacitors connected externally. With the built-in oscillator, either 1.2MHz or 3.0MHz can be selected for suiting to your particular application. As for operation
mode, the XC9235 series is PWM control, the XC9236 series is automatic PWM/PFM switching control and the XC9237 series can be manually switched between the PWM control mode and the automatic PWM/PFM switching control mode, allowing fast response, low ripple and high efficiency over the full range of loads (from light load to heavy load).
The soft start and current control functions are internally optimized. During stand-by, all circuits are shutdown to reduce current consumption to as low as 1.0μA or less. The B/F/G types have a high speed soft-start as fast as 0.25ms in typical for quick turnon. With the built-in UVLO function, the internal P-channel MOS driver transistor is forced OFF when input voltage becomes 1.4V
or lower. The B to G types integrate CL discharge function which enables the electric charge at the output capacitor CL to be discharged via the internal discharge switch located between the LX and VSS pins. When the devices enter stand-by mode, output voltage quickly returns to the VSS level as a result of this function. Four types of package SOT-25, USP-6C, USP-6EL and WLP-5-03 are available.
■APPLICATIONS
●Smart phones / Mobile phones ●Bluetooth ●Mobile devices / terminals ●Portable game consoles ●Digital still cameras / Camcorders ●Note PCs / Tablet PCs
■APPLICATIONS
●Mobile phones, Smart phones
●■BluTeYtoPotIhChAeaLdAsePtsPLICATION CIRCUIT
●Mobile WiMAX PDAs, MIDs, UMPCs
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A/B/C/E/G types (Output VoltagLex Fixed)VIN
VSS
VSS
VSS
VSS
CL (cerCaLmic) (ceramic)
VOUT VOUT
CE/ CMEO/DE MODE
VIN VIN
CIN (ceCraINmic) (ceramic)
CE/MODE CE/MODE
■FEATURES
Driver Transistor Built-In
: 0.42Ω P-ch driver transistor
Input Voltage
0.52Ω N-ch switch transistor : 2.0V ~ 6.0V (A/B/C types)
1.8V ~ 6.0V (D/E/F/G types)
Output Voltage
: 0.8V ~ 4.0V (Internally set) 0.9V ~ 6.0V (Externally set)
High Efficiency Output Current Oscillation Frequency
: 92% (TYP.)* : 600mA : 1.2MHz, 3.0MHz (+15%)
Maximum Duty Cycle
: 100%
Control Methods Function
: PWM (XC9235) PWM/PFM Auto (XC9236) PWM/PFM Manual (XC9237)
: Current Limiter Circuit Built-In (Constant Current & Latching)
Capacitor Operating Ambient Temperature
CL Discharge (B/C/D/E/F/G types) High Speed Soft Start (B/F/G type) : Low ESR Ceramic Capacitor :-40℃ ~ 85℃
Packages
: SOT-25 (A/B/C types only) USP-6C USP-6EL (A/B/C/G types only)
Environmentally Friendly
WLP-5-03 (A/B types only) : EU RoHS Compliant, Pb Free
* Performance depends on external components and wiring on the PCB.
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VOUT 6V0O0mUTA 600mA
L
L
Lx
VIN
Lx
VIN
CL (cerCaLmic) (ceramic)
RFB1 CFB RFB1 CFB
VSS
VSS
VSS
VSS
FB FB
CE/ MCEO/DE MODE
RFB2 RFB2
■TYPICAL PERFORMInpAut VNoltCageE: VINC(VH) ARACTERISTICS
●Efficiency vs. Output Current (fOSC=1.2MHz, VOUT=1.8V)
100 PWM/PFM Automatic Sw itching Control
EfficieEffniccye:ncEyF:FEIF(FI(%)%)
■TYPICAL 98P00 ERFORMANCE CHARACTERISTICS
VIN VIN
●Efficiency
vs.
70
Ou6t0put
VIN= 4.2V
Cu3.r6rVent(fOSC=1.2MHz,PWVMOCUoTn=tro1l .8V)
CIN (ceCraINmic)
50 2.4V
VIN= 4.2V 3.6V
(ceramic)
40
2.4V
CE/MODE
30
CE/MODE
20
10
0
0.1
1
10
100
1000
Output Current:IOUT(mA)
1/33
XC9235/XC9236/XC9237 Series
■BLOCK DIAGRAM
●XC9235 / XC9236 / XC9237 A Series
●XC9235 / XC9236 /PhXaseC9237
Compensation
AVOSUeTries
CFB
R2
Error Amp.
PWM
Comparator
FB R1
.