XC9258 Datasheet, PDF (1/27 Pages) Torex Semiconductor – COT Control, 1.0A Synchronous Step-Down DC/DC Converters

XC9257/XC9258 Series
COT Control, 1.0A Synchronous Step-Down DC/DC Converters
ETR05040-001
˙GENERAL DESCRIPTION
ˑGreenOperation-compatible
The XC9257/XC9258 series is a group of synchronous-rectification type DC/DC converters with a built-in P-channel MOS driver
transistor and N-channel MOS switching transistor, designed to allow the use of ceramic capacitors. Output voltage is internally
set in a range from 0.8V to 3.6V (accuracy: ±2.0%) increments of 0.05V. The device provides a high efficiency, stable power
supply with an output current of 1.0A to be configured using only a coil and two capacitors connected externally. Oscillation
frequency is set to 1.2MHz or 6.0MHz can be selected for suiting to your particular application.
As for operation mode HiSAT-COT ^(*) control excellent in transient response, the XC9257 series is PWM control, the XC9258
series is automatic PWM/PFM switching control, allowing fast response, low ripple and high efficiency over the full range of loads
(from light load to heavy load).
During stand-by, all circuits are shutdown to reduce current consumption to as low as 1.0μA or less. As for the soft-start function
as fast as 0.3ms 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 2.00V or lower. The B types integrate CL High Speed discharge
function which enables the electric charge at the output capacitor CL to be discharged via the internal discharge.
Two types of package SOT-25, USP-6C are available.
(*) _{HiSAT-COT is an original Torex term for High Speed Transient Response.}
˙APPLICATIONS

˔Smart phones / Mobile phones

˙FEATURES
Input Voltage Range
Output Voltage Range
: 2.5Vʙ5.5V
: 0.8Vʙ3.6V (±2.0%)
˔Bluetooth

Oscillation Frequency
: 1.2MHz, 6.0MHz
˔Portable game consoles

˔Digital still cameras / Camcorders

Output Current
Control Methods
: 1A
: HiSAT-COT Control
100% Duty Cycle
˔Point-of-Load (POL)
˔Wearable devices

Protection Circuits
PWM Control (XC9257)
PWM/PFM Auto (XC9258)
: Thermal Shutdown
Current Limit (Pendent character)
Short Circuit Protection (Type B)
Functions
: Soft-Start
UVLO
CL High Speed Discharge (Type B)
Capacitor
: Ceramic Capacitor
Operating Ambient Temperature : - 40ˆ ʙ + 105ˆ
Packages
: SOT-25, USP-6C
Environmentally Friendly
: EU RoHS Compliant, Pb Free
˙TYPICAL APPLICATION CIRCUIT
˙TYPICAL PERFORMANCE
CHARACTERISTICS

XC9257B18C/XC9258B18C
L =LTF5022T-4R7N2R0(4.7ЖH)
C_IN = 10ЖF(GRM155R61A106M) C_L = 10ЖF(GRM155R61A106M
100
90
7_*/7
80
70
7_*/7
60
50
7_*/7
40
7_*/7
30
20
10
0
0.1
9$
9$
1
10
100
Output Current: I_OUT (mA)
1000
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