XC9235_1 Datasheet, PDF (1/33 Pages) Torex Semiconductor – 600mA Driver Tr. Built-In, Synchronous Step-Down DC/DC Converters

XC9235/XC9236/XC9237 Series
ETR0514-011a
600mA Driver Tr. Built-In, Synchronous Step-Down DC/DC Converters
˙GENERAL DESCRIPTION
ˑGreenOperation Compatible
The XC9235/XC9236/XC9237 series is a group of synchronous-rectification type DC/DC converters with a built-in 0.42Њ
P-channel MOS driver transistor and 0.52ЊN-channel MOS switching transistor, designed to allow the use of ceramic
capacitors. Operating voltage range is from 2.0V to 6.0V (AʙC types), 1.8V to 6.0V (DʙG types). For the D/F types which
have a reference voltage of 0.8V (accuracy: ʶ2.0%), 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: ʶ2.0%). 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 1.0ЖA or less. The B/F/G types have a high speed soft-start as fast as 0.25ms in typical for quick
turn-on. With the built-in UVLO (Under Voltage Lock Out) 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 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. When the devices enter stand-by mode, output voltage
quickly returns to the V_SS level as a result of this function.
Three types of package SOT-25 (A/B/C types only), USP-6C, and 0.4mm low height USP-6EL (A/B/C types only) are available.
˙APPLICATIONS
˔Mobile phones, Smart phones
˔Bluetooth headsets
˔Mobile WiMAX PDAs, MIDs, UMPCs
˔Portable game consoles
˔Digital cameras, Camcorders
˔MP3 Players, Portable Media Players
˔Notebook computers
˙TYPICAL APPLICATION CIRCUIT
˔XC9235/XC9236/XC9237
A/B/C/E/G types (Output Voltage Fixed)
˙FEATURES
Driver Transistor Built-In
Input Voltage
Output Voltage
High Efficiency
Output Current
Oscillation Frequency
Maximum Duty Cycle
Control Methods
Function
Capacitor
Packages
Environmentally Friendlyç ç
: 0.42Њ P-ch driver transistor
0.52Њ N-ch switch transistor
: 2.0V ~ 6.0V (A/B/C types)
1.8V ~ 6.0V (D/E/F/G types)
: 0.8V ~ 4.0V
: 92% (TYP.)
: 600mA
: 1.2MHz, 3.0MHz (+15%)
: 100%
: PWM (XC9235)
PWM/PFM Auto (XC9236)
PWM/PFM Manual (XC9237)
: Current Limiter Circuit Built-In
(Constant Current & Latching)
C_L Discharge (B/C/D/E/F/G types)
High Speed Soft Start (B/F/G type)
: Low ESR Ceramic Capacitor
: SOT-25 (A/B/C types only), USP-6C
USP-6EL(A/B/C types only)
ç : EU RoHS Compliant, Pb Free
˔XC9235/XC9236/XC9237
D/F types (Output Voltage Externally Set)
˙TYPICAL PERFORMANCE
CHARACTERISTICS
˔Efficiency vs. Output Currentʢf_OSC=1.2MHz, VOUT=1.8Vʣ
100 ^{PWM/PFM Automatic Sw itching Control}
90
80
70
VIN= 4.2V
60
3.6V
50 ^2.4V
40
30
PWM Control
VIN= 4.2V
3.6V
2.4V
20
10
0
0.1
1
10
100
1000
Output Current:IOUT(mA)
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