XC9510_1 Datasheet, PDF (1/36 Pages) Torex Semiconductor – Synchronous Step-Down DC/DC Converter With Built-In LDO Regulator Plus Voltage Detector

◆Synchronous Step-Down DC/DC Converter
■APPLICATIONS
with Built-In LDO Regulator Plus Voltage Detector
◆Step-Down DC/DC Converter's Output Connected In
Series with LDO Regulator
◆High Efficiency, Low Noise Regulated Output
◆SOP-8 Package for High Current
◆Small-Footprint
◆Output Current DC/DC:800mA, VR: 400mA
●CD-R / RW, DVD
●HDD
●PDAs, portable communication modem
●Cellular phones
●Palmtop computers
●Cameras, video recorders
◆Ceramic Capacitor Compatible (Low ESR capacitors)
■GENERAL DESCRIPTION
The XC9510 series consists of a step-down DC/DC converter
and a high-speed LDO regulator connected in series with the
DC/DC converter's output. A voltage detector is also built-in.
A highly efficient, low noise output is possible since the
regulator is stepped-down further from the DC/DC output.
The DC/DC converter block incorporates a P-channel driver
transistor and a synchronous N-channel switching transistor.
With an external coil, diode and two capacitors, the XC9510
can deliver output currents up to 800mA at efficiencies over
90%. The XC9510 is designed for use with small ceramic
capacitors. A choice of three switching frequencies are
available, 300 kHz, 600 kHz, and 1.2 MHz. Output voltage
settings for the DC/DC is set-up internally in 100mV steps
within the range of 1.6V to 4.0V(±2.0%) and for the VR are
set-up internally within the range of 0.9V to 4.0V (±2.0%).
For the VD, the range is of 0.9V to 5.0V (±2.0%). The soft
start time of the series is internally set to 5ms. 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 1.4 V or lower. The operational states of
the DC/DC and the regulator blocks can be changed by
inputting three kinds of voltage level via the CE/MODE pin. The
functions of the MODE pin can be selected via the external
control pin to switch the DC/DC control mode and the disable
pin to shut down the regulator block.
■FEATURES
Input Voltage Range : 2.4V ~ 6.0V
Low ESR Capacitor : Ceramic capacitor compatible
(Low ESR Capacitors)
VD Function
: Detects output voltage from the
VDOUT pin while sensing either
VDD, DCOUT, or VROUT internally.
N-ch open drain output
<DC/DC Converter Block>
Output Voltage Range : 1.6V ~ 4.0V (Accuracy ±2%)
Output Current
: 800mA
Controls
: PWM Control,
PWM, PWM/PFM
Automatic Switching External
Oscillation Frequency : 300kHz, 600kHz, 1.2MHz
<Regulator Block>
Output Voltage Range : 0.9V ~ 4.0V (Accuracy±2%)
Current Limit
: 600mA
Dropout Voltage
: 160mV @ IOUT=200mA
(VOUT=2.8V)
High Ripple Rejection : 60dB @1kHz (VOUT=2.8V)
■TYPICAL APPLICATION CIRCUIT
■TYPICAL PERFORMANCE
CHARACTERISTICS
XC9510 ETR1007_001.doc
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