XC9210 Datasheet, PDF (1/32 Pages) Torex Semiconductor – Synchronous Step-Down DC / DC Controller ICs

XC9210 Series
Synchronous Step-Down DC / DC Controller ICs
July 4 , 2003 Ver. 3
„ APPLICATIONS
‹Synchronous Step-Down DC/DC Conrollers
‹Input Voltage Range
2.0V ~ 10V
z PDAs
‹Maximum Duty Cycle
‹Output Voltage Externally Set-up
z Palmtop computers
‹Oscillation Frequency
300kHz (Accuracy ±15%)
‹PWM, PWM/PFM Externally Selectable 100% (TYP.)
z Portable audios
‹Synchronous Rectification Control
‹High Efficiency
95% (TYP.)
z Various power supplies
‹Small MSOP-8A Packaging
„ GENERAL DESCRIPTION
The XC9210 is a synchronous PWM, PWM/PFM controller designed
for low voltage step-down DC/DC converter applications. High
efficiency is obtained through the use of a synchronous rectification
topology. Efficiencies are maximised by using the low RDSon N-
Channel MOSFET switch which replaces the catch diode used in
standard buck circuits.
The operation of the XC9210 series can be switched between PWM
and PWM/PFM externally using the MODE pin. In PWM/PFM mode
the XC9210 automatically switches from PWM to PFM during light
loads and high efficiencies can be achieved over a wide range of load
conditions. Output noise is reduced in PWM operation as the
frequency is fixed.
The XC9210 has an 0.9V (±2.0%) internal voltage, and using
externally connected components, the output voltage can be set
freely between 0.9V to 6.0V. With an internal switching frequency of
300kHz and 180kHz (custom) smaller, low cost external components
can also be used.
Soft-start time is internally set to 10msec offering protection against
in-rush currents during start-up and preventing voltage overshoot.
„ FEATURES
Input Voltage Range
Output Voltage Range
Oscillation Frequency
Output Current
Stand-By Function
Package
Soft-start internally set-up
: 2.0V ~ 10V
: 0.9V ~ 6.0V
Can be set freely with 0.9V
(±2.0%) of reference voltage supply
and external components.
: 300kHz ±15%
(180kHz is available as custom)
: More than 2A
(VIN = 5.0V, VOUT=3.3V)
: 3.0µA (MAX.)
: MSOP-8A
: 10 ms (internally set-up)
„ TYPICAL APPLICATION CIRCUIT
<XC9210B093, VOUT:3.3V)
„ TYPICAL PERFORMANCE CHARACTERISTICS
 Efficiency vs. Output Current
Tr1:Pch MOSFET
:CPH3308
PW M
CE
VIN:3.3V~10V
CIN:47µF
EXT1
VDD
PW M
CE
L:22µH
CDRH125
Tr2:Nch MOSFET
:CPH3408
VOUT:3.3V
EXT2
GND
FB
MODE
CFB
:62pF
RFB1
:200kΩ
CL:
47µFX2
MODE
RFB
:75kΩ
XC9210B093K (300kHz, 3.3V)
100
90
80
70
60
50
40
30
20
10
0
0.1
Tr1:CPH3308, Tr2:CPH3408
L=22uH(CDRH125), CL=94uF(Tantalum)
VIN=5.0V
8.0V
PWM/PFM Switching Control
Synchronous PWM Control
1
10 100 1000
Output Current IOUT (mA)
10000
1
Semiconductor Ltd.