XC9210 Series
ETR0504_001
Synchronous Step-Down DC / DC Controller ICs
☆GO-Compatible
■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 maximized 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.
■APPLICATIONS
■FEATURES
●PDAs
Input Voltage Range
: 2.0V ~ 10V
Output Voltage Range
: 0.9V ~ 6.0V
Can be set freely with 0.9V
(±2.0%) of reference
Oscillation Frequency
: 300kHz ±15%
(180kHz as custom)
Output Current
: More than 2A
(VIN = 5.0V, VOUT=3.3V)
Stand-By Function
: 3.0μA (MAX.)
Soft-start internally set-up
: 10 ms (internally set-up)
●Palmtop computers
●Portable audios
●Various power supplies
Synchronous Step-Down DC/DC Controllers
Maximum Duty Cycle
: 100% (TYP.)
PWM and PWM/PFM Externally Selectable
Synchronous Rectification Control
■TYPICAL APPLICATION CIRCUIT
<XC9210B093K
: 95% (TYP.)
Package
: MSOP-8A
■TYPICAL PERFORMANCE
CHARACERISTICS
Efficiency vs. Output Current
OUTPUT=3.3V>
L:22μH
CDRH125
Tr1:Pch MOSFET
:CPH3308
High Efficiency
VOUT:3.3V
Tr2:Nch MOSFET
:CPH3408
CIN:47μF
CFB
:62pF
PWM
CE
VIN:3.3V~10V
EXT1
EXT2
VDD
GND
PWM
CE
RFB1
:200kΩ
CL:
47μFX2
FB
MODE
MODE
RFB
:75kΩ
1/12
XC9210 Series
■PIN CONFIGURATION
1 EXT1
EXT2 8
2 VDD
GND 7
3 PW M
4 CE
FB 6
MODE 8
MSOP-8A
(TOP VIEW)
■PIN ASSIGNMENT
PIN NUMBER
PIN NAME
FUNCTIONS
External Transistor Drive Pin
<Connected to High Side of P-ch Power MOSFET Gate>
1
EXT 1 /
2
VDD
3
PWM
4
CE
5
MODE
6
FB
7
GND
Ground
8
EXT 2
External Transistor Drive Pin
<Connected to Low side of N-ch Power MOSFET Gate>
Supply Voltage
PWM/PFM Switching Pin
<PWM control when connected to VDD, PWM / PFM auto switching when connected to
Ground. >
Chip Enable Pin
<Connected to Ground when output is stand-by mode. Connected to VDD when output is
active. EXT/1 is high and EXT2/ is low when in stand-by mode. >
Synchronous/Non-Synchronous Rectification Switching Pin
<Synchronous operation when MODE pin and PWM pin are connected to VDD,
Non-Synchronous operation when MODE pin and PWM pin are connected to Ground.
Regardless of MODE pin, Non-Synchronous operation when PWM pin is connected to
Ground. >
Output Voltage Monitor Feedback Pin
<Threshold value: 0.9V. Output voltage can be set freely by connecting split resistors
between VOUT and Ground.>
■PRODUCT CLASSIFICATION
●Ordering Information
XC9210①②③④⑤⑥
DESIGNATOR
DESCRIPTION
SYMBOL
①
Type of DC/DC Controller
B
: Standard type
Output Voltage
09
: FB Voltage: 0.9V
④
Oscillation Frequency
2
3
: 180kHz (custom)
: 300kHz
⑤
Package
K
: MSOP-8A
⑥
Devise Orientation
R
L
: Embossed tape, standard feed
: Embossed tape, reverse feed
②
2/12
③
DESCRIPTION
XC9210
Series
■ BLOCK DIAGRAM
■ ABSOLUTE MAXIMUM RATINGS
Ta = 25℃
PARAMETER
SYMBOL
RATINGS
UNITS
VDD Pin Voltage
VDD
- 0.3 ~ 12.0
V
FB Pin Voltage
VFB
- 0.3 ~ 12.0
V
CE Pin Voltage
VCE
- 0.3 ~ 12.0
V
PWM Pin Voltage
VPWM
- 0.3 ~ 12.0
V
MODE Pin Voltage
VMODE
- 0.3 ~ 12.0
V
EXT1, 2 Pin Voltage
VEXT
- 0.3 ~ VDD + 0.3
V
EXT1, 2 Pin Current
IEXT
±100
mA
Power Dissipation
Pd
150
mW
Operating Temperature Range
Topr
- 40 ~ + 85
℃
Storage Temperature Range
Tstg
- 55 ~ +125
℃
3/12
XC9210 Series
■ ELECTRICAL CHARACTERISTICS
XC9210B093
(FOSC = 300kHz)
PARAMETER
SYMBOL
Supply Voltage
VDD
Maximum Input Voltage
VIN
Output Voltage Range
( *1)
VOUTSET
CONDITIONS
MIN.
Ta=25℃
TYP. MAX. UNITS
CIRCUIT
MODE = 0V
2.0
-
10.0
V
①
MODE = 0V
10.0
-
-
V
①
0.9
-
VIN
V
①
-
65
120
μA
②
VIN≧2.0V, MODE = 0V,
IOUT=1mA
Supply Current 1
IDD1
FB = 0V
VOUT
Supply Current 2
IDD2
FB = 1.0V
-
65
120
μA
②
Stand-by Current
ISTB
Same as IDD1, CE = 0V
-
-
3.0
μA
②
Oscillation Frequency
FOSC
255
300
345
kHz
②
FB Voltage
VFB
V
③
Minimum Operation Voltage
VINmin
2.0
V
①
Maximum Duty Ratio
MAXDTY
Minimum Duty Ratio
MINDTY
PFM Duty Ratio
PFMDTY
Efficiency1
(*2)
EFFI
Soft-Start Time
TSS
EXT1 "High" ON Resistance
REXTBH1
Same as IDD1
VIN=3.0V, IOUT=10mA
0.882 0.900 0.918
-
-
Same as IDD1
100
-
-
%
②
Same as IDD2
-
-
0
%
②
No Load, VPWM=0V
22
30
38
%
④
(*3)
-
96
-
%
④
VOUT1×0.95V, CE=0V→0.65V
5.0
10.0
20.0
ms
④
-
26
37
Ω
⑤
IOUT1=300mA
CE1 = 0, EXT1= VDD - 0.4V
EXT1 "Low" ON Resistance
REXTBL1
FB = 0V, EXT1 = 0.4V
-
19
30
Ω
⑤
EXT2 "High" ON Resistance
REXTBH2
EXT2 = VDD - 0.4V
-
23
31
Ω
⑤
EXT2 "Low" ON Resistance
REXTBL2
CE = 0V, EXT2 = VDD - 0.4V
-
19
30
Ω
⑤
PWM "High" Voltage
VPWMH
No Load
0.65
-
-
V
④
PWM "Low" Voltage
VPWML
No Load
-
-
0.20
V
④
MODE "High" Voltage
VMODEH
No Load
0.65
-
-
V
④
MODE "Low" Voltage
VMODEL
No Load
-
-
0.20
V
④
CE "High" Voltage
VCEH
FB = 0V
0.65
-
-
V
②
CE "Low" Voltage
VCEL
FB = 0V
-
-
0.2
V
②
PWM "High" Current
IPWMH
-
-
0.5
μA
②
PWM "Low" Current
IPWML
PWM=0V
-
-
- 0.5
μA
②
MODE "High" Current
IMODEH
-
-
0.5
μA
②
MODE "Low" Current
IMODEL
-
-
- 0.5
μA
②
CE "High" Current
ICEH
-
-
0.5
μA
②
CE "Low" Current
ICEL
FB "High" Current
IFBH
FB "Low" Current
IFBL
MODE = 0V
CE = 0V
FB = 1.0V
-
-
- 0.5
μA
②
-
-
0.50
μA
②
-
-
- 0.50
μA
②
Unless otherwise stated, VDD = 3.0V, CE = 3.0V, PWM = 3.0V, FB = 3.0V, EXT1, 2=OPEN, MODE = 3.0V, VIN=4.2V
NOTE: *1： Please be careful not to exceed the breakdown voltage level of the peripheral parts.
*2： EFFI={ [ (output voltage) x (output current) ] / [ (input voltage) x (input current) ] } x 100
*3：
Tr1: CPH3308
(SANYO)
Tr2: CPH3408
(SANYO)
(CDRH125, SUMIDA)
L: 22μH
CL: 16V, 47μF x 2
(Tantalum MCE Series, NICHICEMI)
(Tantalum MCE Series, NICHICEMI)
CIN: 16V, 47μF
RFB1: 200kΩ
RFB2: 75kΩ
CFB: 62pF
4/12
XC9210
Series
■ ELECTRICAL CHARACTERISTICS (Continued)
XC9210B092
(FOSC = 180kHz)
PARAMETER
SYMBOL
Supply Voltage
VDD
Maximum Input Voltage
VIN
Output Voltage Range
(*1)
VOUTSET
CONDITIONS
MIN.
Ta=25℃
TYP. MAX. UNITS
CIRCUIT
MODE = 0V
2.0
-
10.0
V
①
MODE = 0V
10.0
-
-
V
①
0.9
-
VIN
V
①
VIN≧2.0V, MODE = 0V,
IOUT=1mA
VOUT
Supply Current 1
IDD1
FB = 0V
-
45
105
μA
②
Supply Current 2
IDD2
FB = 1.0V
-
45
105
μA
②
②
Stand-by Current
ISTB
Oscillation Frequency
FOSC
FB Voltage
VFB
Minimum Operation Voltage
VINmin
Maximum Duty Ratio
MAXDTY
Minimum Duty Ratio
MINDTY
PFM Duty Ratio
PFMDTY
-
-
3.0
μA
153
180
207
kHz
②
Same as IDD1, CE = 0V
Same as IDD1
VIN=3.0V, IOUT=10mA
V
③
2.0
V
①
-
-
%
②
-
0
%
②
0.882 0.900 0.918
-
-
Same as IDD1
100
Same as IDD2
22
30
38
%
④
EFFI
IOUT1=300mA
(*3)
-
96
-
%
④
Soft-Start Time
TSS
VOUT1×0.95V, CE=0V→0.65V
5.0
10.0
20.0
ms
④
EXT1 "High" ON Resistance
REXTBH1
CE1 = 0, EXT1= VDD - 0.4V
-
26
37
Ω
⑤
EXT1 "Low" ON Resistance
REXTBL1
FB = 0V, EXT1 = 0.4V
-
19
30
Ω
⑤
EXT2 "High" ON Resistance
REXTBH2
EXT2 = VDD - 0.4V
-
23
31
Ω
⑤
EXT2 "Low" ON Resistance
REXTBL2
CE = 0V, EXT2 = VDD - 0.4V
-
19
30
Ω
⑤
PWM "High" Voltage
VPWMH
No Load
0.65
-
-
V
④
PWM "Low" Voltage
VPWML
No Load
-
-
0.20
V
④
MODE "High" Voltage
VMODEH
No Load
0.65
-
-
V
④
MODE "Low" Voltage
VMODEL
No Load
-
-
0.20
V
④
CE "High" Voltage
VCEH
FB = 0V
0.65
-
-
V
②
CE "Low" Voltage
VCEL
FB = 0V
-
-
0.20
V
②
PWM "High" Current
IPWMH
-
-
0.50
μA
②
②
Efficiency1
(*2)
PWM "Low" Current
IPWML
MODE "High" Current
IMODEH
MODE "Low" Current
IMODEL
CE "High" Current
ICEH
CE "Low" Current
ICEL
FB "High" Current
IFBH
FB "Low" Current
IFBL
No Load, VPWM=0V
PWM=0V
MODE = 0V
CE = 0V
FB = 1.0V
-
-
- 0.50
μA
-
-
0.50
μA
②
-
-
- 0.50
μA
②
-
-
0.50
μA
②
-
-
- 0.50
μA
②
-
-
0.50
μA
②
-
-
- 0.50
μA
②
Unless otherwise stated, VDD = 3.0V, CE = 3.0V, PWM = 3.0V, FB = 3.0V, EXT1,2 = OPEN, MODE = 3.0V, VIN=4.2V
NOTE: *1 : Please be careful not to exceed the breakdown voltage level of the peripheral parts.
*2 : EFFI={ [ (output voltage) x (output current) ] / [ (input voltage) x (input current) ] } x 100
*3 :
Tr1: CPH3308
(SANYO)
Tr2: CPH3408
(SANYO)
L: 22μH
(CDRH125, SUMIDA)
(Tantalum MCE Series, NICHICEMI)
CL: 16V, 47μF x 2
CIN: 16V, 47μF
(Tantalum MCE Series, NICHICEMI)
RFB1: 200kΩ
RFB2: 75kΩ
CFB: 62pF
5/12
XC9210 Series
■ OPERATIONAL EXPLANATION
The XC9210 series are 2 channel step-down DC/DC converter controller ICs with built-in high speed, low ON resistance
drivers.
<Error Amp>
The error amplifier is designed to monitor the output voltage and it compares the feedback voltage (FB) with the reference
voltage. In response to feedback of a voltage lower than the reference voltage, the output voltage of the error amp.
decreases.
<OSC Generator>
This circuit generates the oscillation frequency, which in turn generates the source clock.
<Ramp Wave Generator>
The ramp wave generator generates a saw-tooth waveform based on outputs from the phase shift generator.
<PWM Comparator>
The PWM Comparator compares outputs from the error amp. and saw-tooth waveform. When the voltage from the error
amp's output is low, the external switch will be set to ON.
<PWM/PFM Controller>
This circuit generates PFM pulses.
Control can be switched between PWM control and PWM/PFM automatic switching control using external signals.
The PWM/PFM automatic switching mode is selected when the voltage of the PWM pin is less than 0.2V, and the control
switches between PWM and PFM automatically depending on the load. As the PFM circuit generates pulses based on
outputs from the PWM comparator, shifting between modes occurs smoothly. PWM control mode is selected when the
voltage of the PWM pin is more than 0.65V. Noise is easily reduced with PWM control since the switching frequency is fixed.
Control suited to the application can easily be selected which is useful in audio applications, for example, where traditionally,
efficiencies have been sacrificed during stand-by as a result of using PWM control (due to the noise problems associated
with the PFM mode in stand-by).
<Synchronous, blank logic>
The Synchronous, blank logic circuit is to prevent penetration of the transistor connected to EXT1 and EXT2. Synchronous
can be switched between Synchronous rectification and Non-Synchronous rectification automatically by using external
signals. When the MODE pin's voltage is 0.2V or less, the mode will be non-synchronous rectification and operations will
recommence. The EXT2 pin will be kept at a low level (the external N-type MOSFET will be OFF). When the MODE pin's
and PWM pin's voltage is 0.65V or more, the mode will be synchronous rectification and operations will recommence.
<Vref with Soft Start>
The reference voltage, Vref (FB pin voltage)=0.9V, is adjusted and fixed by laser trimming (for output voltage settings,
please refer to next page). To protect against inrush current, when the power is switched on, and also to protect against
voltage overshoot, soft-start time is set internally to 10ms. It should be noted, however, that this circuit does not protect the
load capacitor (CL) from inrush current. With the Vref voltage limited and depending upon the input to the error amps, the
operation maintains a balance between the two inputs of the error amps and controls the EXT pin's ON time so that it doesn't
increase more than is necessary.
<Chip Enable Function>
This function controls the operation and shutdown of the IC. When the voltage of the CE pin is 0.2V or less, the mode will
be chip disable, the channel's operations will stop. The EXT1 pin will be kept at a high level (the external P-ch MOSFET
will be OFF) and the EXT2 pin will be kept at a low level (the external N-ch MOSFET will be OFF). When CE pin is in a
state of chip disable, current consumption will be no more than 3.0μA.
When the CE pin's voltage is 0.65V or more, the mode will be chip enable and operations will recommence. With soft-start,
95% of the set output voltage will be reached within 10mS (TYP.) from the moment of chip enable.
6/12
XC9210
Series
■ OPERATIONAL EXPLANATION (Continued)
< Output Voltage Setting >
Output voltage can be set by adding external split resistors. Output voltage is determined by the following equation, based
on the values of RFB11 (RFB21) and RFB12 (RFB22). The sum of RFB11 (RFB21) and RFB12 (RFB22) should normally be 1 MΩ or
less.
VOUT = 0.9×( RFB11 + RFB12 ) / RFB12
The value of CFB1(CFB2), speed-up capacitor for phase compensation, should be fzfb= 1 / (2×π×CFB1×RFB11) which is
equal to 12kHz. Adjustments are required from 1kHz to 50kHz depending on the application, value of inductance (L), and
value of load capacity (CL).
When RFB11 = 200kΩ and RFB12 = 75kΩ, VOUT1 = 0.9×( 200k + 75k ) / 75k = 3.3V.
[Example of Calculation]
[Typical Example]
VOUT
(V)
1.2
1.5
1.8
2.0
2.2
[External Components]
RFB11
(kΩ)
110
220
220
330
390
RFB12
(kΩ)
330
330
220
270
270
CFB1
(pF)
100
62
62
39
33
VOUT
(V)
2.5
2.7
3.0
3.3
5.0
RFB11
(kΩ)
390
360
560
200
82
RFB12
(kΩ)
220
180
240
75
18
CFB1
(pF)
33
33
24
62
160
Transistor :
●Low Input Voltage (2.0V ≦ VIN ≦ 5.0V, IOUT ≦ 2A)
EXT1: CPH6315 (P-ch MOSFET: SANYO), IRLMS6702 (P-ch MOSFET: IR)
EXT2: CPH3409 (N-ch MOSFET: SANYO), IRLMS1902 (P-ch MOSFET: IR)
●High Input Voltage (5.0V ≦ VIN ≦ 10.0V, IOUT ≦ 2A)
EXT1: CPH3308 (P-ch MOSFET: SANYO), IRLMS5703 (P-ch MOSFET: IR)
EXT2: CPH3408 (N-ch MOSFET: SANYO), IRLMS1503 (P-ch MOSFET: IR)
L:
22μH
CIN: 16V, 47μF (Tantalum MCE Series, NICHICEMI)
(CDRH125, SUMIDA)
CL: 16V, 47μF x 2 (Tantalum MCE Series, NICHICEMI)
SD: CMS02
(Schottky Barrier Diode, TOSHIBA)
■EXTERNAL COMPONENTS
●COIL
PART NUMBER MANUFACTURER
CDR125-220
SUMIDA
●INPUT / OUTPUT CAPACITANCE
PART NUMBER MANUFACTURER
16MCE476MD2
NICHICHEMI
L VALUE
(μH)
22
SERIAL
RESISTANCE (Ω)
36m
VOLTAGE (V)
16.0
RATED CURRENT
(A)
2.8
CAPACITANCE (μF)
47
W x L (mm)
H (mm)
12.3×12.3
6.0
W x L (mm)
4.6×5.8
H (mm)
3.2±0.2
W x L (mm)
H (mm)
2.4×4.7
0.98±0.1
●SCHOTTKY BARRIER DIODE
REVERSE FORWARD
PART NUMBER MANUFACTURER CURRENT CURRENT
CMS02
TOSHIBA
30
3
●TRANSISTOR (P-ch MOSFET)
ABSOLUTE MAX. RATINGS
PART
NUMBER MANUFACTURER VDSS (V) VGSS (V) ID (A)
CPH6315
SANYO
- 20
±10
- 3.0
CPH3308
SANYO
- 30
±20
- 4.0
IRLMS6702
IR
- 20
±12
- 2.3
IRLMS5703
IR
- 30
±20
- 2.3
●TRANSISTOR (N-ch MOSFET)
PART
ABSOLUTE MAX. RATINGS
NUMBER MANUFACTURER VDSS (V) VGSS (V) ID (A)
CPH3409
SANYO
30
±10
5.0
CHP3408
SANYO
30
±20
5.0
IRLMS1902
IR
20
±12
3.2
IRLMS1503
IR
30
±20
3.2
VFmax (V)
IRmax (A)
0.4 (IF=3A) 0.5m (VR=30V)
RDS (ON)
MAX.(mΩ)
150 (Vgs= -4.0V)
140 (Vgs= -4.0V)
200 (Vgs= -4.5V)
400 (Vgs= -4.5V)
RDS (ON)
MAX.(mΩ)
42 (Vgs=4.0V)
68 (Vgs=4.0V)
100 (Vgs=4.5V)
200 (Vgs=4.5V)
Ciss (TYP.) (pF) VGS (off) (V)
410 (Vds= -10V)
560 (Vds= -10V)
210 (Vds= -15V)
170 (Vds= -25V)
- 1.4 (MAX.)
- 2.4 (MAX.)
- 0.7 (MAX.)
- 1.0 (MAX.)
Ciss (TYP.) (pF) VGS (off) (V)
630 (Vds= 10V)
480 (Vds= 10V)
300 (Vds= 15V)
210 (Vds= 25V)
1.3 (MAX.)
2.4 (MAX.)
0.7 (MAX.)
1.0 (MAX.)
PKG.
CPH6
CPH3
Micro6
Micro6
PKG.
CPH6
CPH3
Micro6
Micro6
7/12
XC9210 Series
■TEST CIRCUITS
Circuit ① :
L:
CL:
CIN:
PNP Tr 1:
Tr 2:
RFB:
CFB:
8/12
22μH (CDRH125, SUMIDA)
16MCE476MD2 (Tantalum Type, NIHONCHEMICON)
16MCE476MD2 (Tantalum Type, NIHONCHEMICON)
2SA1213 (TOSHIBA)
CPH3409 (SANYO)
Please use by the conditions as below.
RFB1 + RFB2 ≦1MΩ
RFB1 / RFB2 = (Setting Output Voltage / 0.9) -1
fztb = 1 / (2 x π x CFB x RFB1) =1kHz ~ 50kHz (12kHz usual)
Circuit ③ :
L:
CL:
CIN:
Tr 1:
Tr 2:
22μH (CDRH125, SUMIDA)
16MCE476MD2 (Tantalum Type, NIHONCHEMICON)
16MCE476MD2 (Tantalum Type, NIHONCHEMICON)
CPH6315 (SANYO)
CPH3409 (SANYO)
Circuit ④ :
L:
CL:
CIN:
Tr 1:
Tr 2:
22μH (CDRH125, SUMIDA)
16MCE476MD2 (Tantalum Type, NIHONCHEMICON)
16MCE476MD2 (Tantalum Type, NIHONCHEMICON)
CPH3308 (SANYO)
CPH3409 (SANYO)
XC9210
Series
■NOTES ON USE
1. Checking for Intermittent Oscillation
The XC9210 series is subject to intermittent oscillation in the proximity of the maximum duty if the step-down ratio is low
(e.g., from 4.2 V to 3.3 V) or a heavy load is applied where the duty ratio becomes high. Check waveforms at EXT under
your operating conditions. A remedy for this problem is to raise the inductance of coil L or increase the load capacitance CL
and use OS-CON for the load capacitance CL. When using OS-CON for the load capacitance and setting output voltage
low, the series could produce an abnormal oscillation. In such case, please test with the actual device.
2. PWM/PFM Automatic Switching
If PWM/PFM automatic switching control is selected and the step-down ratio is high (e.g., from 10 V to 1.0 V), the control mode
remains in PFM setting over the whole load range, since the duty ratio under continuous-duty condition is smaller than the PFM
duty ratio of the XC9210 series. The output voltage's ripple voltage becomes substantially high under heavy load conditions,
with the XC9210 series appearing to be producing an abnormal oscillation. If this operation becomes a concern, set pins
PWM1 and PWM2 to High to set the control mode to PWM setting. For use under the above-mentioned condition, measured
data of PWM/PFM automatic switching control shown on the data sheets are available up to IOUT = 100 mA.
3. Ratings
Use the XC9210 series and peripheral components within the limits of their ratings.
4. Reverse Current
Reverse current is produced under the
conditions of synchronous operation and light
load (current flows from the output to the input).
If this reverse current becomes a concern,
operate under synchronous rectification during
heavy load conditions, or move input
capacitance CIN closer to the IC to reduce the
reverse current to the power supply.
* The light load condition mentioned above means that the load current when the coil current being discontinuous at
non-synchronous operation. The heavy load condition means that the load current when the coil current being continuous at
non-synchronous operation. The DC/DC simulation on the TOREX website is useful to determine whether the coil current is
non-synchronous or synchronous under your operating conditions. After the simulation, please test with the actual device.
Coil current when non-synchronous
(DiscontinuousMode)
Coil current when synchronous
Coil curren
Comparison among non-synchronous operation (left), synchronous operation (center) and the coil current on a
like-for-like basis. Synchronous of the current IL< 0mA becomes reverse current.
To prevent the reverse current, operate in the condition of ILmin > 0mA (right).
5. Switching Method of Operational Mode / Control
PWM
MODE
OPERATIONAL MODE / CONTROL
'H'
'H'
Synchronous, PWM Control
'H'
'L'
Non-Synchronous, PWM Control
'L'
'H'
Non-Synchronous, PFM / PWM Automatic Switching Control
'L'
'L'
Non-Synchronous, PFM / PWM Automatic Switching Control
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XC9210 Series
■NOTES ON USE (Continued)
6. Notes on How to Select Transistor
Synchronous rectification operation prepares fixed time when switching changes so that the high side P-ch MOSFET and
the low side N-ch MOSFET do not oscillate simultaneously. Also it is designed to prevent the penetration current when the
both MOSFET oscillate at the same time. However, some MOSFET may oscillate simultaneously and worsen efficiency.
Please select MOSFET with high Vth with small input capacity on high side P-ch MOSFET and the low side N-ch MOSFET.
(When using with large current, please note that there is a tendency for ON resistance to become large when the input
capacity of MOSFET is small and Vth is high.)
7. Instruction on Layout
(1) The performance of the XC9120 DC/DC converter is greatly influenced by not only its own characteristics, but also by
those of the external components it is used with. We recommend that you refer to the specifications of each
component to be used and take sufficient care when selecting components.
(2) Please mount each external component as close to the IC as possible. Wire external components as close to the IC
as possible and use thick, short connecting wires to reduce wiring impedance. In particular, minimize the distance
between the EXT pin and the Gate pin of the low side of N-ch MOSFET.
(3) Make sure that the GND wiring is as strong as possible as variations in ground potential caused by ground current at
the time of switching may result in unstable operation of the IC. Specifically, strengthen the ground wiring in the
proximity of the VSS pin.
(4) For stable operation, please connect by-pass capacitor between the VDD and the GND.
■TYPICAL APPLICATION CIRCUIT
L
Lx P in
Tr1:P c h MO S FE T
V OU T
Tr2:Nc h M OS F ET
SBD
CIN
CF B
PWM
CE
V IN
10/12
EX T1
E XT 2
VDD
GND
PW M
CE
RF B1
CL
FB
M O DE
M ODE
RF B2
XC9210
Series
■ PACKAGING INFORMATION
●MSOP-8A
■ MARKING RULE
●MSOP-8A
① Represents product series
MARK
PRODUCT SERIES
5
XC9210B09xKx
② Represents type of DC/DC Controller
MSOP-8A
(TOP VIEW)
MARK
PRODUCT SERIES
B
XC9210B09xKx
③,④ Represents FB voltage
MARK
③
④
VOLTAGE
（V）
0
9
0.9
PRODUCT SERIES
XC9210B09xKx
⑤ Represents oscillation frequency
MARK
OSCILLATION FREQUENCY (kHz)
PRODUCT SERIES
2
3
180 (Custom)
300
XC9210B092Kx
XC9210B093Kx
⑥ Represents production lot number
0 to 9,A to Z repeated (G, I, J, O, Q, W excepted)
Note: No character inversion used.
11/12
XC9210 Series
1. The products and product specifications contained herein are subject to change without
notice to improve performance characteristics.
Consult us, or our representatives
before use, to confirm that the information in this catalog is up to date.
2. We assume no responsibility for any infringement of patents, patent rights, or other
rights arising from the use of any information and circuitry in this catalog.
3. Please ensure suitable shipping controls (including fail-safe designs and aging
protection) are in force for equipment employing products listed in this catalog.
4. The products in this catalog are not developed, designed, or approved for use with such
equipment whose failure of malfunction can be reasonably expected to directly
endanger the life of, or cause significant injury to, the user.
(e.g. Atomic energy; aerospace; transport; combustion and associated safety
equipment thereof.)
5. Please use the products listed in this catalog within the specified ranges.
Should you wish to use the products under conditions exceeding the specifications,
please consult us or our representatives.
6. We assume no responsibility for damage or loss due to abnormal use.
7. All rights reserved. No part of this catalog may be copied or reproduced without the
prior permission of Torex Semiconductor Ltd.
12/12