PWMControlledStep-DownDC/DCConverters
Series
535
5
The XC9201 series are step-up multiple current and voltage feedback
DC/DC controller ICs. Current sense, clock frequencies and amp
feedback gain can all be externally regulated.
A stable power supply is possible with output currents of up to 3.0A.With
output voltage fixed internally, VOUT is selectable in 0.1V steps within a
1.2V - 16.0V range (± 2.5%).
For output voltages outside this range, we recommend the FB version
which has a 0.9V internal reference voltage. Using this version, the
required output voltage can be set-up using 2 external resistors.
Switching frequencies can also be set-up externally within a range of
100~600 kHz and therefore frequencies suited to your particular
application can be selected.
With the current sense function, peak currents (which flow through the
driver transistor and the coil) can be controlled. Soft-start time can be
adjusted using external resistors and capacitors.
During shutdown (CE pin =L), consumption current can be reduced to as
little as 0.5µA (TYP.) or less and with U.V.L.O
(Under Voltage Lock Out) built-in, the external transistor will be
automatically shut off below the regulated voltage.
■GeneralDescription
●Stable Operations via Current & Voltage Multiple Feedback
●Unlimited Options for Peripheral Selection
●Current Protection Circuit
●Ceramic Capacitor Compatible
●Mobile, Cordless phones
●Palm top computers, PDAs
●Portable games
●Cameras, Digital cameras
●Laptops
■Features
■Applications
◆Input Voltage Range : 2.5V ~20V
◆Output Voltage Range : 1.2V ~ 16V
◆Oscillation Frequency Range : 100kHz ~
600kHz
◆Output Current : up to 3.0A
◆Ceramic Capacitor Compatible
◆MSOP-8A Package
0
20
40
60
80
100
0.1 1 10 100 1000 10000
OutputCurrent：IOUT（mA）
Efficiency：EFFI(%)
7.2V
15.0V
VIN=5.4V
10.0V
12.0V
22μH
10KΩ 220pF
CLK5
1EXT
2Isen
3VIN
4CE/SS
VOUT7
GAIN6
Vss8
470pF
40μF+220μF
33mΩ
XP132A11A1SR
U3FWJ44N
1μF
240kΩ
0.33μF
94μF
■TypicalApplicationCircuit ■TypicalPerformance
Characteristic
VOUT:5.0V FOSC:330kHz
05S1XC9201/9202新規02.09.1215:16ページ535
■PackagingInformation
●MSOP-8A
XC9201Series
536
5
■PinConfiguration ■PinAssignment
■ProductClassification
●Ordering Information
1
2
3
4
6
5
7
8
EXT
Isen
VIN
CE／SS
CC／GAIN
CLK
VOUT／FB
VSS
PINNUMBER PINNAME FUNCTION
1 EXT Driver
2 Isen CurrentSense
3V
IN PowerInput
4 CE／SS CE/SoftStart
5 CLK ClockInput
6 CC／GAIN PhaseCompensation
7V
OUT／FB VoltageSense
8V
SS Ground
ＸＣ９２０１
DESIGNATOR
SYMBOL DESCRIPTION
CVOUT
D
Number
FB
A
K
R Embossedtape.StandardFeed
Embossedtape.ReverseFeed
L
OutputVoltage:Forvoltagesabove10V,seebelow:
10=A,11=B,12=C,13=D,14=E,15=F,16=H
e.g.VOUT=2.3V→w=2,e=3VOUT=13.5V→w=D,e=5
FBproducts→w=0,e=9fixed
Soft-startexternallyset-up
Soft-startexternallyset-up
MSOP-8A
AdjustableFrequency
ThestandardoutputvoltagesoftheXC9201Cseriesare2.5V,3.3V,and5.0V.
Voltagesotherthanthoselistedaresemi-custom.
3.00±0.10
4.90±0.10
3.00±0.10
0.53±0.13
0〜6ﾟ
0.00〜0.20
0.30 +0.08
-0.02
1.02
0.86
+0.11
-0.10
+0.20
-0.21
0.15 +0.08
-0.02
(0.65)
05S1XC9201/9202新規02.09.1215:16ページ536
XC9201
Series
537
5
■Marking
q Representstheproductseries
SYMBOL
1
PRODUCTNAME
XC9201***AK*
w Representstheproducttype,DC/DCconverter
SYMBOL
C
PRODUCTNAME
D
TYPE
VOUT、CEPIN
FB、CEPIN
e Representsintegralnumberofoutputvoltage,orFBtype
SYMBOL
1
PRODUCTNAME
2
VOLTAGE
1.X
2.X
3 3.X
4 4.X
5 5.X
6 6.X
7 7.X
8 8.X
9 9.X
0
FBproducts
SYMBOL
A
PRODUCTNAME
B
VOLTAGE
10.X
11.X
C 12.X
D 13.X
E 14.X
F 15.X
H 16.X
r Representsdecimalnumberofoutputvoltage
SYMBOL
0
PRODUCTNAME
3
VOLTAGE
X.0
X.3
9 FBproducts
t Representsoscillatorfrequeney'scontroltype
SYMBOL
A
PRODUCTNAME
XC9201***AK*
TYPE
AdjustableFrequency
MSOP8A
qwe
rty
XC9201C**AK*
XC9201D09AK*
XC9201C1*AK*
XC9201C2*AK*
XC9201C3*AK*
XC9201C4*AK*
XC9201C5*AK*
XC9201C6*AK*
XC9201C7*AK*
XC9201C8*AK*
XC9201C9*AK*
XC9201D09AK*
XC9201CA*AK*
XC9201CB*AK*
XC9201CC*AK*
XC9201CD*AK*
XC9201CE*AK*
XC9201CF*AK*
XC9201CH*AK*
XC9201C*0AK*
XC9201C*3AK*
XC9201D09AK*
05S1XC9201/9202新規02.09.1215:16ページ537
XC9201Series
538
5
■AbsoluteMaximumRatings
■BlockDiagram
EXT
ISEN
VIN
CE/SS
VSS
VOUT
CC/GAIN
CLK
RampWave,
InternalCLK
generator
ChipEnable,
SoftStartup,
U.V.L.O.
Verr
PWM
Ierr
Internal
Voltage
Regulator
EXTtimming
controll
logic
Current
Limit
Protection
Limittercomp.
Vrefgenerator
CE,UVLO
tointernal
circuit 0.9V
Sampling
R1
R2
MIX
2.0V
tointernal
circuit
PARAMETER
EXTPinVoltage
SYMBOL RATINGS UNITS
−0.3〜＋22
Ｖ
ISENPinVoltage
VINPinVoltage
CE/SSPinVoltage
CLKPinVoltage
VOUT/FBPinVoltage
EXTPinCurrent
StorageTemperature
VEXT
VIsen
VIN
VCE
VCLK
VOUT/FB
IEXT
Tstg
−0.3〜VDD＋0.3
−0.3〜＋22
−0.3〜＋22
−0.3〜VDD＋0.3
−0.3〜＋22
±100
−55〜＋125
Ｖ
Ｖ
Ｖ
Ｖ
Ｖ
mA
ContinuousTotal
PowerDissipation Pd 150 mW
OperatingAmbient
Temperature Topr −40〜＋85 ℃
℃
Ta=25℃
CC/GAINPinVoltage VCC −0.3〜VDD＋0.3 Ｖ
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XC9201
Series
539
5
■ElectricalCharacteristics
XC9201C25AR
VIN=3.75Vunlessspecified
*1:Onresistance=0.4V/measurementcurrent
NOTE1:EFFI={[(OutputVoltage)x(OutputCurrent)]÷[(InputVoltage)x(InputCurrent)]}x100
NOTE2:ThecapacityrangeofthecondenserusedtosettheexternalCLKfrequencyis180∼300pF
Ta=25℃
PARAMETER SYMBOL CONDITIONS MIN. TYP. MAX. UNITS
MaximumOperating
Voltage
MinimumOperating
Voltage
CLKOscillation
Frequency
SupplyCurrent1
Stand-byCurrent
FrequencyTemperature
Fluctuation
MaximumDutyCycle
MinimumDutyCycle
VINmax
OutputVoltage VOUT
VINmin
IDD1
ISTB
FOSC
FrequencyInput
Stability
ΔFOSC
ΔVIN･FOSC
ΔFOSC
ΔTOPR･FOSC
MAXDTY
MINDTY
CurrentLimiterVoltage
ISENCurrent
ILIM
IISEN
CE"High"Current
CE"Low"Current
ICEH
ICEL
CE"High"Voltage VCEH
EXTvoltage=High
VIN=3.75V,CE=VIN=VOUT
VIN=20.0V,CE=VIN,VOUT=VSS
VIN=3.75V,CE=VOUT=VSS
RT=10.0kΩ,CT=220pF
VIN=2.5V〜20V
TOPR=−40〜+85℃
VIN=3.75V
IOUT=300mA
VOUT=VSS
VOUT=VIN
VINpinvoltage-ISENpinvoltage
VIN=3.75V,ISEN=3.75V
CE=VIN=20.0V,VOUT=0V
CE=0V,VIN=20.0V,VOUT=0V
ExistanceofCLKOscillation,
VOUT=0V,CE：Voltageapplied
DissapearanceofCLKOscillation,
VOUT=0V,CE：Voltageapplied
EXT=VIN−0.4V,CE=VOUT=VIN*1
EXT=0.4V,CE=VIN,VOUT=VSS*1
ConnectCSSandRSS,CE:0V→3.75V
2.438
20
−
1.0
280
100
90
4.5
−0.1
−0.1
0.6
2.500
−
−
1.400
115
130
0.5
330
±5
±5
150
7
0
0
2.562
−
2.200
2.0
220
235
2.0
380
0
220
13
0.1
0.1
V
V
V
V
μA
μA
μA
kHz
%
%
%
%
mV
μA
μA
μA
V
CE"Low"Voltage VCEL 
0.2 V
EXT"High"
ONResistance REXTH 27
40 Ω
EXT"Low"
ONResistance REXTL 24
33 Ω
Efficiency(NOTE1) EFFI 93
%
Soft-startTime TSS 5 10
20 ms
CC/GAINPin
OutputImpedance RCCGAIN 400
kΩ
CIRCUITS
q
q
q
t
w
w
w
e
e
e
r
r
y
y
t
t
t
t
r
r
q
q
u
SupplyCurrent2 IDD2
U.V.L.O.Voltage VUVLO
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XC9201Series
540
5
XC9201C33AR
VIN=5.0Vunlessspecified
*1:Onresistance=0.4V/measurementcurrent
NOTE1:EFFI={[(OutputVoltage)x(OutputCurrent)]÷[(InputVoltage)x(InputCurrent)]}x100
NOTE2:ThecapacityrangeofthecondenserusedtosettheexternalCLKfrequencyis180∼300pF
Ta=25℃
PARAMETER SYMBOL CONDITIONS UNITS
MaximumOperating
Voltage
MinimumOperating
Voltage
SupplyCurrent1
Stand-byCurrent
FrequencyTemperature
Fluctuation
MaximumDutyCycle
MinimumDutyCycle
VINmax
OutputVoltage VOUT
VINmin
IDD1
ISTB
CLKOscillation
Frequency
FOSC
Frequency
InputStability
ΔFOSC
ΔVIN･FOSC
ΔFOSC
ΔTOPR･FOSC
MAXDTY
MINDTY
CurrentLimiter
Voltage
ISENCurrent
ILIM
IISEN
CE"High"Current
CE"Low"Current
ICEH
ICEL
CE"High"Voltage VCEH
EXTvoltage=High
VIN=5.0V,CE=VIN=VOUT
VIN=20.0V,CE=VIN,VOUT=VSS
VIN=5.0V,CE=VOUT=VSS
RT=10.0kΩ,CT=220pF
VIN=2.5V〜20V
Topr=−40〜+85℃
VIN=5.0V
IOUT=300mA
VOUT=VSS
VOUT=VIN
VINpinvoltage-ISENpinvoltage
VIN=5.0V,ISEN=5.0V
CE=VIN=20.0V,VOUT=0V
CE=0V,VIN=20.0V,VOUT=0V
ExistanceofCLKOscillation,
VOUT=0V,CE:Voltageapplied
DissapearanceofCLKOscillation,
VOUT=0V,CE:Voltageapplied
EXT=VIN-0.4V,CE=VOUT=VIN*1
EXT=0.4V,CE=VIN,VOUT=VSS*1
ConnectCSSandRSS,CE:0V→5.0V
3.218
20
−
1.0
280
100
90
4.5
−0.1
−0.1
0.6
3.300
−
−
1.400
115
130
0.5
330
±5
±5
150
7
0
0
3.382
−
2.200
2.0
220
235
2.0
380
0
220
13
0.1
0.1
V
V
V
V
μA
μA
μA
kHz
%
%
%
%
mV
μA
μA
μA
V
CE"Low"Voltage VCEL 
0.2 V
EXT"High"
ONResistance
EXT"Low"
ONResistance
CC/GAINPin
OutputImpedance
REXTH 24
33 Ω
REXTL 22
31 Ω
Efficiency(NOTE1) EFFI 93
%
Soft-startTime TSS 5 10
20 ms
RCCGAIN 400
kΩ
CIRCUITS
q
q
q
t
w
w
w
e
e
e
r
r
y
y
t
t
t
t
r
r
q
q
u
SupplyCurrent2 IDD2
U.V.L.O.Voltage VUVLO
MIN. TYP. MAX.
05S1XC9201/9202新規02.09.1215:16ページ540
XC9201
Series
541
5
XC9201C50AR
VIN=7.5Vunlessspecified
*1:Onresistance=0.4V/measurementcurrent
NOTE1:EFFI={[(OutputVoltage)x(OutputCurrent)]÷[(InputVoltage)x(InputCurrent)]}x100
NOTE2:ThecapacityrangeofthecondenserusedtosettheexternalCLKfrequencyis180∼300pF
Ta=25℃
VINmax
VOUT
VINmin
IDD1
ISTB
FOSC
ΔFOSC
ΔVIN･FOSC
ΔFOSC
ΔTOPR･FOSC
MAXDTY
MINDTY
ILIM
IISEN
ICEH
ICEL
VCEH
EXTvoltage=High
VIN=7.5V,CE=VIN=VOUT
VIN=20.0V,CE=VIN,VOUT=VSS
VIN=7.5V,CE=VOUT=VSS
RT=10.0kΩ,CT=220pF
VIN=2.5V〜20V
TOPR=−40〜+85℃
VIN=7.5V
IOUT=300mA
VOUT=VSS
VOUT=VIN
VINpinvoltage-ISENpinvoltage
VIN=7.5V,ISEN=7.5V
CE=VIN=20.0V,VOUT=0V
CE=0V,VIN=20.0V,VOUT=0V
ExistanceofCLKOscillation,
VOUT=0V,CE：Voltageapplied
DissapearanceofCLKOscillation,
VOUT=0V、CE：Voltageapplied
VEXT=VIN−0.4V,CE=VOUT=VIN*1
VEXT=0.4V,CE=VIN,VOUT=VSS*1
ConnectCSSandRSS,CE:0V→7.5V
4.875
20
−
1.0
280
100
90
4.5
−0.1
−0.1
0.6
5.000
−
−
1.400
115
130
0.5
330
±5
±5
150
7
0
0
5.125
−
2.200
2.0
220
235
2.0
380
0
220
13
0.1
0.1
V
V
V
V
μA
μA
μA
kHz
%
%
%
%
mV
μA
μA
μA
V
VCEL 
0.2 V
REXTH 21
29 Ω
REXTL 20 27 Ω
EFFI 93
%
TSS 5 10
20 ms
RCCGAIN 400
kΩ
q
q
q
t
w
w
w
e
e
e
r
r
y
y
t
t
t
t
r
r
q
q
u
IDD2
VUVLO
MIN. TYP. MAX.
PARAMETER
MinimumOperating
Voltage
MaximumOperating
Voltage
SupplyCurrent1
Stand-byCurrent
MinimumDutyCycle
OutputVoltage
CLKOscillation
Frequency
Frequency
InputStability
CurrentLimiter
Voltage
ISENCurrent
CE"High"Voltage
CE"Low"Voltage
CE"High"Voltage
CE"Low"Voltage
EXT"High"
ONResistance
EXT"Low"
ONResistance
CC/GAINPin
OutputImpedance
Efficiency(NOTE1)
Soft-startTime
SupplyCurrent2
U.V.L.O.Voltage
SYMBOL CONDITIONS UNITS
CIRCUITS
FrequencyTemperature
Fluctuation
MaximumDutyCycle
05S1XC9201/9202新規02.09.1215:16ページ541
XC9201Series
542
5
XC9201D09AR
VIN=4.0Vunlessspecified
Externalcomponents:RFB1=200kΩ,RFB2=100kΩ,CFB=82pF
*1:Onresistance=0.4V/measurementcurrent
NOTE1:EFFI={[(OutputVoltage)x(OutputCurrent)]÷[(InputVoltage)x(InputCurrent)]}x100
NOTE2:ThecapacityrangeofthecondenserusedtosettheexternalCLKfrequencyis180∼300pF
Ta=25℃
UNITS
VINmax
VFB
VINmin
IDD1
ISTB
FOSC
ΔFOSC
ΔVIN･FOSC
ΔFOSC
ΔTOPR･FOSC
MAXDTY
MINDTY
ILIM
IISEN
ICEH
ICEL
VCEH
EXTvoltage=High
VIN=4.0V,CE=VIN=FB
VIN=20.0V,CE=VIN,FB=VSS
VIN=4.0V,CE=FB=VSS
RT=10.0kΩ,CT=220pF
VIN=2.5V〜20V
TOPR=−40〜+85℃
VIN=4.0V
IOUT=300mA
FB=VSS
FB=VIN
VINpinvoltage-ISENpinvoltage
VIN=4.0V,ISEN=4.0V
CE=VIN=20.0V,FB=0V
CE=0V,VIN=20.0V,FB=0V
ExistanceofCLKOscillation,
FB=0V,CE：Voltageapplied
DissapearanceofCLKOscillation,
FB=0V、CE：Voltageapplied
EXT=VIN−0.4V,CE=FB=VIN*1
EXT=0.4V,CE=VIN,FB=VSS*1
ConnectCSSandRSS,CE:0V→4.0V
0.8775
20
1.0
280
100
90
4.5
−0.1
−0.1
0.6
0.900
1.400
115
130
0.5
330
±5
±5
150
7
0
0
0.9225
2.200
2.0
220
235
2.0
380
0
220
13
0.1
0.1
V
V
V
V
μA
μA
μA
kHz
%
%
%
%
mV
μA
μA
μA
V
VCEL 
0.2 V
REXTH 27
40 Ω
REXTL 24
34 Ω
EFFI 93
%
TSS 5 10
20 ms
RCCGAIN 400
kΩ
CIRCUITS
q
q
q
t
w
w
w
e
e
e
r
r
y
y
t
t
t
t
r
r
q
q
u
IDD2
VUVLO
MIN. TYP. MAX.
PARAMETER SYMBOL CONDITIONS
MaximumOperating
Voltage
MinimumOperating
Voltage
SupplyCurrent1
Stand-byCurrent
FrequencyTemperature
Fluctuation
MaximumDutyCycle
MinimumDutyCycle
FBVoltage
CLKOscillation
Frequency
Frequency
InputStability
CurrentLimiter
Voltage
ISENCurrent
CE"High"Current
CE"Low"Current
CE"High"Voltage
CE"Low"Voltage
EXT"High"
ONResistance
EXT"Low"
ONResistance
CC/GAINPin
OutputImpedance
Efficiency(NOTE1)
Soft-startTime
SupplyCurrent2
U.V.L.O.Voltage
05S1XC9201/9202新規02.09.1215:16ページ542
XC9201
Series
543
5
3.3V
〜1.5A
47μF(OS)or
10μF(ceramic)×4
VSS
VOUT
CC/GAIN
〜30kΩ220pF
470pF
CLK
8
7
6
5
22μH
1 EXT
Isen
2
3V
IN
4 CE/SS
1μF
SD
47
7.2V
50mΩ
PMOS
240kΩ
μF 0.22μF
■TypicalApplicationCircuits
XC9201C33AKR
5.0V
〜1.5A
47μF(OS)
+220μF(any)
VSS
VOUT
CC/GAIN
〜30kΩ
220pF
470pF
CLK
8
7
6
5
22μH
1EXT
Isen
2
3VIN
4 CE/SS
1μF
SD
12.0V
20mΩ
PMOS
240kΩ
0.33μF
47μF
+220μF
PMOS : XP132A11A1SR(TOREX)
Coil : 22µH(CR105 SUMIDA)
Resistor : 50mΩfor Isen (NPR1 KOWA), 30kΩ(trimmer) for CLK, 240kΩfor SS
Capacitors : 220pF( ceramic) for CLK, 470pF(ceramic) for CC/GAIN, 0.22µF(any) for SS,1µF(ceramic) for Bypass
47µF(OS) or 10µF(ceramic) x 4 for CL, 47µF(tantalum) for CIN
SD : U3FWJ44N(TOSHIBA)
XC9201C50AKR
PMOS : XP132A11A1SR(TOREX)
Coil : 22µH(CDRH127 SUMIDA)
Resistor : 20mΩfor Isen (NPR1 KOWA), 30kΩ(trimmer) for CLK, 240kΩfor SS
Capacitors : 220pF(ceramic) for CLK, 470pF(ceramic) for CC/GAIN, 0.33µF(any) for SS, 1µF(ceramic) for Bypass
47µF(OS)+220µF(any) for CL, 47µF(tantalum)+220µF(any) for CIN
SD : U3FWJ44N(TOSHIBA)
05S1XC9201/9202新規02.09.1215:16ページ543
XC9201Series
544
5
2.5V
〜3A
47uF(OS)
+220μF(any)
VSS
VOUT
CC/GAIN
〜30kΩ
220kΩ
220pF
39pF
470pF
CLK
8
7
6
5
22μH
1EXT
Isen
2
3VIN
4 CE/SS
1μF
SD
7.2V
20mΩ
PMOS
240kΩ
390kΩ
0.22μF
47μF
+220μF
12V
〜1.5A
47μF(OS)
+220μF
VSS
FB
CC/GAIN
〜30kΩ
22kΩ
220pF
56pF
470pF
CLK
8
7
6
5
47μH
1EXT
Isen
2
3V
IN
4 CE/SS
XC9201D09AKR
1μF
SD
20V
50mΩ
PMOS
240kΩ
270kΩ
0.47μF
47μF
XC9201D09AKR
PMOS : XP132A11A1SR(TOREX)
Coil : 22µH(CDRH127 SUMIDA)
Resistors : 20mΩfor Isen (NPR1 KOWA), 30kΩ(trimmer) for CLK, 240kΩfor SS, 390kΩfor Output Voltage
100kΩ(trimmer) for Output Voltage
Capacitors : 220pF(ceramic) for CLK, 470pF(ceramic) for CC/GAIN, 0.22µF(any) for SS, 1µF(ceramic) for Bypass
39pF(ceramic) for FB,47µF(OS) for CL,47µF (tantalum)+220µF(any) for CIN
SD : U3FWJ44N(TOSHIBA)
PMOS : XP132A11A1SR(TOREX)
Coil : 47µH(CR105 SUMIDA)
Resistor : 50mΩfor Isen (NPR1 KOWA), 30kΩ(trimmer) for CLK, 240kΩfor SS, 270kΩfor Output Voltage
22kΩ(trimmer) for Output Voltage
Capacitors : 220pF(ceramic) for CLK, 470pF(ceramic) for CC/GAIN, 0.47µF(any) for SS, 1µF(ceramic) for Bypass
100pF(ceramic) for FB, 47µF(OS) +220µF(any) for CL, 47µF(tantalum)+220µF(any) for CIN
SD : U3FWJ44N(TOSHIBA)
05S1XC9201/9202新規02.09.1215:16ページ544
XC9201
Series
545
5
■OperationDescription
Step-down DC/DC converter controllers of the XC9201series carry out pulse width modulation (PWM) according to the multiple feedback signals
of the output voltage and coil current.
The internal circuits consist of different blocks that operate at VIN or the stabilized power (2.0 V) of the internal regulator. The output setting
voltage of type C controller and the FB pin voltage (Vref = 0.9 V) of type D controller have been adjusted and set by laser-trimming.
<Clock>
With regard to clock pulses, a capacitor and resistor connected to the CLK pin generate ramp waveforms whose top and bottom are 0.7 V and
0.15 V, respectively. The frequency can be set within a range of 100 to 600 kHz externally (refer to the "Functional Settings" section for further
information). The clock pulses are processed to generate a signal used for synchronizing internal sequence circuits.
<Verr amplifier>
The Verr amplifier is designed to monitor the output voltage. A fraction of the voltage applied to internal resistors R1, R2 in the case of a type C
controller, and the voltage of the FB pin in the case of a type D controller, are fed back and compared with the reference voltage. In response to
feedback of a voltage lower than the reference voltage, the output voltage of the Verr amplifier increases.
The output of the Verr amplifier enters the mixer via resistor (RVerr). This signal works as a pulse width control signal during PWM operations.
By connecting an external capacitor and resistor through the CE/GAIN pin, it is possible to set the gain and frequency characteristics of Verr
amplifier signals (refer to the "Functional Settings" section for further information).
<Ierr amplifier>
The Ierr amplifier monitors the coil current. The potential difference between the VIN and Isen pins is sampled at each switching operation.
Then the potential difference is amplified or held, as necessary, and input to the mixer. The Ierr amplifier outputs a signal ensuring that the
greater the potential difference between the VIN and Isen pins, the smaller the switching current. The gain and frequency characteristics of this
amplifier are fixed internally.
<Mixer and PWM>
The mixer modulates the signal sent from Verr by the signal from Ierr. The modulated signal enters the PWM comparator for comparison with
the sawtooth pulses generated at the CLK pin. If the signal is greater than the sawtooth waveforms, a signal is sent to the output circuit to turn
on the external switch.
<Current Limiter>
The current flowing through the coil is monitored by the limiter comparator via the VIN and Isen pins. The limiter comparator outputs a signal
when the potential difference between the VIN and Isen pins reaches 150 mV or more. This signal is converted to a logic signal and handled as
a DFF reset signal for the internal limiter circuit. When a reset signal is input, a signal is output immediately at the EXT pin to turn off the MOS
switch. When the limiter comparator sends a signal to enable data acceptance, a signal to turn on the MOS switch is output at the next clock
pulse. If at this time the potential difference between the VIN and Isen pins is large, operation is repeated to turn off the MOS switch again. DFF
operates in synchronization with the clock signal of the CLK pin.
<Soft Start>
The soft start function is made available by attaching a capacitor and resistor to the CE/SS pin. The Vref voltage applied to the Verr amplifier is
restricted by the start-up voltage of the CE/SS pin. This ensures that the Verr amplifier operates with its two inputs in balance, thereby
preventing the ON-TIME signal from becoming stronger than necessary. Consequently, soft start time needs to be set sufficiently longer than
the time set to CLK. The start-up time of the CE/SS pin equals the time set for soft start (refer to the "Functional Settings" section for further
information).
The soft start function operates when the voltage at the CE/SS pin is between 0V to 1.55V. If the voltage at the CE/SS pin doesn't start from 0V
but from a mid level voltage when the power is switched on, the soft start function will become ineffective and the possibilities of large inrush
currents and ripple voltages occurring will be increased.
Undervoltage Lock Out (U.V.L.O.) is also provided. This function is activated to turn off the MOS switch attached to the EXT pin when the input
voltage (VIN) decreases to approximately 1.4 V or below. The purpose of this function is to keep the external MOS switch from turning on when
a voltage at which the IC operates unstably is applied. U.V.L.O. also restricts signals during soft start so that the external MOS switch does not
turn on until the internal circuitry becomes stable.
05S1XC9201/9202新規02.09.1215:16ページ545
●Functional Settings
1. Soft Start
CE and soft start (SS) functions are commonly assigned to the CE/SS pin. The soft start function is effective until the voltage at the CE pin
reaches approximately 1.55 V rising from 0 V. Soft start time is approximated by the equation below according to values of Vcont, RSS, and
CSS.
T=-Css x Rss x ln((Vcont-1.55)/Vcont)
Example: When Css=0.1µF,Rss=470kΩ, and Vcont=5V, T=-0.1e-6 ×470e3×In((5-1.55)/5)=17.44ms.
Set the soft start time to a value sufficiently longer than the period of a clock pulse.
> Circuit example 1: N-ch open drain
> Circuit example 2: CMOS logic (low current dissipation)
> Circuit example 3: CMOS logic (low current dissipation), quick off
XC9201Series
546
5
CE/SSpin
〔InsidetheIC〕
Css
Rss
ON/OFFsignal
Vcont
CE/SSpin
〔InsidetheIC〕
Css
Rss
ON/OFFsignal
Vcont
CE/SSpin
〔InsidetheIC〕
Css
Rss
ON/OFFsignal
Vcont
CE/SSpin 〔InsidetheIC〕
Vcont Css
CE,
UVLO Vrefcircuit ToVerramplifier
Rss
05S1XC9201/9202新規02.09.1215:16ページ546
2.Oscillation Frequency
The oscillation frequency of the internal clock generator is approximated by the following equation according to the values of the capacitor and
resistor attached to the CLK pin. To stabilize the IC's operation, set the oscillation frequency within a range of 100kHz to 600kHz. Select a
value for Cclk within a range of 180pF to 300pF and fix the frequency based on the value for Rclk.
f=1/ (-Cclk x Rclk x ln 0.26)
Example: When Cclk = 220 pF and Rclk = 10 kΩ, f = 1/(-220e-12 x 10e3x ln(0.26)) = 337.43 kHz.
3.Gain and Frequency Characteristics of the Verr Amplifier
The gain at output and frequency characteristics of the Verr amplifier are adjusted by the values of capacitor and resistor attached to the
CC/GAIN pin. It is generally recommended to attach a C_GAIN of 220 to 1,000 pF without an R_GAIN. The greater the C_GAIN value, the
more stable the phase and the slower the transient response. When using the IC with R_GAIN connected, it should be noted that if the R_GAIN
resistance value is too high, abnormal oscillation may occur during transient response time. The size of R_GAIN should be carefully determined
and connected.
4.Current Limiting
The current limiting value is approximated by the following equation according to resistor RSEN inserted between the VIN and ISEN pins. Double
function, current FB input and current limiting, is assigned to the ISEN pin. The current limiting value is approximated by the following equation
according to the value for RSEN.
ILpeak_limit = 0.15 / RSEN
Example: When RSEN = 100 mΩ, ILpeak_limit = 0.15 / 0.1 = 1.5 A
Because of the feedback at the internal error amp with this IC (which is brought about as a result of the phase compensation of the voltage
generated at RSEN, which is in turn caused by current flowing through the coil when the PMOS is working.), should the value of the RSEN resistor
be too large, the feedback signal will also increase and intermittent oscillation may occur. We therefore recommend that you carefully check the
value for RSEN should you have a problem with oscillation. During normal operations, a voltage will be generated at RSEN as a result of the coil's
peak current. Please ensure that this voltage is less than the current limit voltage which is 90mV (min.).
For RSEN resistor's rated power, please refer to the note on the RSEN resistor on page 18.
XC9201
Series
547
5
CLKpin
〔InsidetheIC〕
Rclk CLKGenerater
Cclk
〔InsidetheIC〕
Rsen
VINpin
Isenpin
Limitersignal
Comparatorwith
150-mVoffset
〔InsidetheIC〕
Verr
CC/GAINpin
RGAIN
CC
VOUT/FB
Vref
RVerr
05S1XC9201/9202新規02.09.1215:16ページ547
XC9201Series
548
5
■Directionsforuse
●Application Notes
1. The 9201 series are designed for use with an output ceramic capacitor. If, however, the potential difference between input and output is too
large, a ceramic capacitor may fail to absorb the resulting high switching energy and oscillation could occur on the output side. If the input-
output potential difference is large, connect an electrolytic capacitor in parallel to compensate for insufficient capacitance.
2. The EXT pin of the XC9201 series is designed to minimize the through current that occurs in the internal circuitry. However, the gate drive of
external PMOS has a low impedance for the sake of speed. Therefore, if the input voltage is high and the bypass capacitor is attached away
from the IC, the charge/discharge current to the external PMOS may lead to unstable operations due to switching operation of the EXT pin.
As a solution to this problem, place the bypass capacitor as close to the IC as possible, so that voltage variations at the VIN and VSS pins
caused by switching are minimized. If this is not effective, insert a resistor of several to several tens of ohms between the EXT pin and PMOS
gate. Remember that the insertion of a resistor slows down the switching speed and may result in reduced efficiency.
3. A PNP transistor can be used in place of PMOS. If using a PNP transistor, insert a resistor (Rb) and capacitor (Cb) between the EXT pin and
the base of the PNP transistor in order to limit the base current without slowing the switching speed. Adjust Rb in a range of 500Ωto 1kΩ
according to the load and hFE of the transistor. Use a ceramic capacitor for Cb, complying with Cb < 1/ ( 2 x πx Rb x Fosc x 0.7), as a rule.
4. This IC incorporates a limit comparator to monitor the voltage produces across the RSEN resistor at the current peak of the coil. It functions as
a limiter when, for example, the output is short-circuited. In such a case, the limit comparator senses that the voltage across the RSEN resistor
has reached a current-limiting voltage (typically 150mV) and outputs a signal to turn off the external transistor. After sensing a current-limiting
voltage, the limit comparator typically takes 200nsec before it turns off the external resistor. During this time, the voltage across the RSEN
resistor can exceed the current-limiting voltage, especially when the difference between the input voltage and the output voltage is large and
the coil inductance is small. Therefore, exercise great care in selecting absolute maximum ratings of the external transistor, coil, and
Schottky diode.
5. If the difference between the input voltage and the output voltage is large or small, the switching ON time or OFF time of this IC becomes
short and actual operation can be critically influenced by values of peripheral components 'inductance of coil, resistance of CLK connection,
capacitance of capacitor, etc.) Before use, it is recommended to evaluate this IC thoroughly with an actual unit.
〔InsidetheIC〕
FBpin
Rfb1
Rfb2
Verramplifier
0.9V
Cfb
Outputvoltage
Verr
5. FB Voltage and Cfb
With regard to the XC9201D series, the output voltage is set by attaching externally divided resistors. The output voltage is determined by the
equation shown below according to the values of Rfb1 and Rfb2. In general, the sum of Rfb1 and Rfb2 should be 1 MEG Ωor less.
VOUT = 0.9 x (Rfb1 + Rfb2)/Rfb2
The value of Cfb (phase compensation capacitor) is approximated by the following equation according to the values of Rfb1 and fzfb. The value
of fzfb should be 10 kHz, as a general rule.
Cfb = 1/(2 x πx Rfb1 x fzfb)
Example: When Rfb1 = 455 kΩand Rfb2 = 100 kΩ: VOUT = 0.9 x (455 k + 100 k)/100 k = 4.995 V
: Cfb = 1/(2 x πx 455 k x 10 k) = 34.98 pF.
〔InsidetheIC〕
VIN
EXTpin
Rb
Cb
05S1XC9201/9202新規02.09.1215:16ページ548
PowerGND
ICGND
VDDLine
ThroughHole
RFB1
CFB
CL
RFB2
CGAIN
RCLK
5
6
7
8
CDD
L
P-MOS
RSEN
1
2
3
4
SD
VIN CIN
CSS
RSS
1
2
3
4
ThroughHole
5
6
7
8
RCLK,CCLK,CGAIN,RFB2 
GND
CCLK
●Recommended Pattern Layout
qIn order to stabilize VDD's voltage level, we recommend that a by-pass condenser (CDD) be connected as close as possible to the VIN & VSS
pins.
wIn order to stabilize the GND voltage level which can fluctuate as a result of switching, we suggest that C_CLK's, R_CLK's & C_GAIN's GND
be separated from Power GND and connected as close as possible to the VSS pin (by-pass condenser, CDD). Please use a multi layer board
and check the wiring carefully.
Pattern Layout Examples
XC9201 Series (D Series)
2 layer Evaluation Board
XC9201
Series
549
5
05S1XC9201/9202新規02.09.1215:16ページ549
●Notes on Use
Ensure that the absolute maximum ratings of the external components and the XC9201 DC/DC IC itself are not exceeded. We recommend
that sufficient counter measures are put in place to eliminate the heat that may be generated by the external P-MOSFET as a result of
switching losses.
Try to use a P-MOSFET with as small a gate capacitance as possible in order to avoid overly large output spike voltages that may occur
(such spikes occur in proportion to gate capacitance). The performance of the XC9201 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.
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 by-pass capacitor and the IC.
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.
●External Components
RSENSE Resistor
A low value resistor is defined as a resistor with a 10Ωvalue or lower. For RSENSE, the XC9201 series uses a resistor with a value of either
50mΩor 100mΩ. Although resistors for RSENSE are classified as low resistance chip resistors or current limit resistors (which may give the
impression that the RSENSE resistor is expensive), it is not necessary to use expensive low resistance chip resistors as general purpose chip
resistors with values of 50mΩor 100mΩwill do the job just as well.
When choosing the RSENSE resistor, it is important to confirm the resistor's power consumption which can be done using the following
equation:
W (Power Consumption) =I (Current) x V (Voltage)
=I (Current) x I (Current) x R (Resistance)
It is recommended that a resistor which has a power rating of more than 3 times the power consumption of RSENSE be selected (refer to the
example given below) :
(ex.) RSENSE = 100mΩ, I = 1A
I = 1A
RSENSE = 100mΩ(0.1Ω)
Power supply W = 1 x 1 x 0.1 = 0.1 [W] 0.5W, 100mΩresistor should be used
XC9201Series
550
5
PowerGND
ICGND
VDDLine
RFB1
CL
RFB2
CFB
CDD
L
P-MOS
1
2
3
4
5
6
SD
VIN CIN
CSS
RSS
RSEN
CGAINCCLKRCLK
7
8
1 layer Evaluation Board
05S1XC9201/9202新規02.09.1215:16ページ550
XC9201
Series
551
5
■TestCircuits
・Fig.1(VOUTType)
22μH
100mΩ
PMOS
SD
RSS
CSS
47μH
CLK5
1EXT
2Isen
4CE/SS
GAIN6
Vss8
10KΩ 220pF 470pF
1μF
47μF
3VIN
VOUT7
20μF
RL V
 XC9201C25ARSS：188kΩCSS：0.1μF
XC9201C33ARSS：270kΩCSS：0.1μF
XC9201C50ARSS：430kΩCSS：0.1μF
A
10KΩ
220pF
CLK5
1EXT
2Isen
3VIN
4CE/SS
GAIN6
Vss8
0.1μF
VOUT/FB7
CLK5
1EXT
2Isen
3VIN
4CE/SS
GAIN6
Vss8
VOUT/FB7
CLK5
1EXT
2Isen
3VIN
4CE/SS
GAIN6
Vss8
VOUT/FB7
CLK5
1EXT
2Isen
3VIN
4CE/SS
GAIN6
Vss8
VOUT/FB7
CLK5
1EXT
2Isen
3VIN
4CE/SS
GAIN6
Vss8
VOUT/FB7
CLK5
1EXT
2Isen
3VIN
4CE/SS
GAIN6
Vss8
VOUT/FB7
A
H
10KΩ
220pF
0.1μF
L
10KΩ
0.1μF
VA
220pF 0.1μF
1MΩ V
CLK5
1EXT
2Isen
3VIN
4CE/SS
FB7
GAIN6
Vss8
PMOS
SD
20KΩ
165pF
470pF 22μF
RL
100mΩ
1μF
240kΩ
0.047μF
47μF
CFB RFB1
RFB2
10KΩ 220pF
0.1μF OSC
10KΩ
220pF
0.1μF A
V
V
V
・Fig.2
・Fig.4
・Fig.3
・Fig.1(FBType)
・Fig.5
・Fig.6 ・Fig.7
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XC9201Series
552
5
■TypicalPerformance
Characteristics
XC9201D09AKR
(1) OUTPUT VOLTAGE vs. OUTPUT CURRENT
VOUT1.5V,FOSC:330kHz
1.3
1.4
1.5
1.6
1.7
0.1 1 10 100 1000 10000
3.1
3.2
3.3
3.4
3.5
0.1 1 10 100 1000 10000
11.8
11.9
12.0
12.1
12.2
0.1 1 10 100 1000 10000
4.8
4.9
5.0
5.1
5.2
0.1 1 10 100 1000 10000
L=22µH,CL=40µF(Ceramic),CIN=30µF(Ceramic)
RSEN=50mΩ,CDD=1µF(Ceramic),SD:U3FWJ44N
CGAIN=470pF(Ceramic),Tr:XP162A11C0PR
VOUT3.3V,FOSC:330kHz
L=22µH,CL=40µF(Ceramic),CIN=30µF(Ceramic)
RSEN=50mΩ,CDD=1µF(Ceramic),SD:U3FWJ44N
CGAIN=470pF(Ceramic),Tr:XP162A11C0PR
VOUT5.0V,FOSC:330kHz
L=22µH,CL=40µF(Ceramic),CIN=30µF(Ceramic)
RSEN=50mΩ,CDD=1µF(Ceramic),SD:U3FWJ44N
CGAIN=470pF(Ceramic),Tr:XP162A11C0PR
VOUT12.0V,FOSC:100kHz
L=68µH,CL=40µF(Ceramic),CIN=30µF(Ceramic)
RSEN=50mΩ,CDD=10µF(Ceramic),SD:U3FWJ44N
CGAIN=470pF(Ceramic),Tr:XP132A11C0PR
VIN=4.0V
6.0V
8.0V
10.0V
12.0V
VIN=3.3V
5.0V
7.2V
VIN=18.0V
VIN=8.0V
10.0V
12.0V
15.0V
OutputCurrent:IOUT(mA)
OutputCurrent:IOUT(mA)
OutputCurrent:IOUT(mA)
OutputCurrent:IOUT(mA)
OutputVoltage:VOUT(V)
OutputVoltage:VOUT(V)
OutputVoltage:VOUT(V)
OutputVoltage:VOUT(V)
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XC9201
Series
553
5
(2) EFFICIENCY vs. OUTPUT CURRENT
L=22µH,CL=40µF(Ceramic),CIN=30µF(Ceramic)
RSEN=50mΩ,CDD=1µF(Ceramic),SD:U3FWJ44N
CGAIN=470pF(Ceramic),Tr:XP162A11C0PR
L=22µH,CL=40µF(Ceramic),CIN=30µF(Ceramic)
RSEN=50mΩ,CDD=1µF(Ceramic),SD:U3FWJ44N
CGAIN=470pF(Ceramic),Tr:XP162A11C0PR
L=22µH,CL=40µF(Ceramic),CIN=30µF(Ceramic)
R
SEN
=50mΩ,CDD=1µF(Ceramic),SD:U3FWJ44N
CGAIN=470pF(Ceramic),Tr:XP162A11C0PR
L=68µH,CL=40µF(Ceramic),CIN=30µF(Ceramic)
RSEN=50mΩ,CDD=10µF(Ceramic),SD:U3FWJ44N
CGAIN=470pF(Ceramic),Tr:XP132A11C0PR
VOUT1.5V,FOSC:330kHz VOUT3.3V,FOSC:330kHz
VOUT5.0V,FOSC:330kHz VOUT12.0V,FOSC:100kHz
0
20
40
60
80
100
0.1 1 10 100 1000 10000
OutputCurrent:IOUT(mA)
Efficiency:EFFI(%)
VIN=18.0V
0
20
40
60
80
100
0.1 1 10 100 1000 10000
OutputCurrent:IOUT(mA)
Efficiency:EFFI(%)
VIN=8.0V 12.0V
10.0
15.0V
0
20
40
60
80
100
0.1 1 10 100 1000 10000
OutputCurrent:IOUT(mA)
Efficiency:EFFI(%)
VIN=4.0V
10.0V
8.0V
6.0V
12.0V
0
20
40
60
80
100
0.1 1 10 100 1000 10000
OutputCurrent:IOUT(mA)
Efficiency:EFFI(%)
VIN=3.3V
5.0V
7.2V
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XC9201Series
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5
(3) RIPPLE VOLTAGE vs. OUTPUT CURRENT
L=22µH,CL=40µF(Ceramic),CIN=30µF(Ceramic)
RSEN=50mΩ,CDD=1µF(Ceramic),SD:U3FWJ44N
CGAIN=470pF(Ceramic),Tr:XP162A11C0PR
L=22µH,CL=40µF(Ceramic),CIN=30µF(Ceramic)
RSEN=50mΩ,CDD=1µF(Ceramic),CD:U3FWJ44N
CGAIN=470pF(Ceramic),Tr:XP162A11C0PR
L=22µH,CL=40µF(Ceramic),CIN=30µF(Ceramic)
RSEN=50mΩ,CDD=1µF(Ceramic),SD:U3FWJ44N
CGAIN=470pF(Ceramic),Tr:XP162A11C0PR
L=68µH,CL=40µF(Ceramic),CIN=30µF(Ceramic)
RSEN=50mΩ,CDD=10µF(Ceramic),SD:U3FWJ44N
CGAIN=470pF(Ceramic),Tr:XP132A11C0PR
VOUT1.5V,FOSC:330kHz VOUT3.3V,FOSC:330kHz
VOUT5.0V,FOSC:330kHz VOUT12.0V,FOSC:100kHz
L=22µH,CL=47µF(Tantalum),CIN=47µF(Tantalum)
RSEN=50mΩ,CDD=1µF(Ceramic),SD:U3FWJ44N
CGAIN=470pF(Ceramic),Tr:XP162A11C0PR
L=22µH,CL=47µF(Tantalum),CIN=47µF(Tantalum)
RSEN=50mΩ,CDD=1µF(Ceramic),SD:U3FWJ44N
CGAIN=470pF(Ceramic),Tr:XP162A11C0PR
VOUT1.5V,FOSC:330kHz VOUT3.3V,FOSC:330kHz
0
20
40
60
80
100
0.1 1 10 100 1000 10000
OutputCurrent:IOUT(mA)
0
20
40
60
80
100
0.1 1 10 100 1000 10000
OutputCurrent:IOUT(mA)
0
20
40
60
80
100
0.1 1 10 100 1000 10000
OutputCurrent:IOUT(mA)
0
20
40
60
80
100
0.1 1 10 100 1000 10000
OutputCurrent:IOUT(mA)
0
20
40
60
80
100
0.1 1 10 100 1000 10000
OutputCurrent:IOUT(mA)
0
20
40
60
80
100
0.1 1 10 100 1000 10000
OutputCurrent:IOUT(mA)
RippleVoltage:Vr(mVp-p)
RippleVoltage:Vr(mVp-p) RippleVoltage:Vr(mVp-p)
RippleVoltage:Vr(mVp-p)
RippleVoltage:Vr(mVp-p)
RippleVoltage:Vr(mVp-p)
VIN=4.0V
6.0V
8.0V
10.0V
12.0V
VIN=3.3V
5.0V
7.2V
VIN=18.0V
VIN=8.0V
15.0V
10.0V
12.0V
6.0V
8.0V 10.0V
12.0V
VIN=4.0V
VIN=3.3V
7.2V
5.0V
*Note: If the input and output voltage differential is large or small, the time of ON and Off switching will be shorten.
This gives external components such as inductance value of coil, connecting a resistor to CLK, condenser, will critically influence the
actual operation.
05S1XC9201/9202新規02.09.1215:16ページ554