XC9235/XC9236/XC9237 Series
ETR0514-014
600mA Driver Tr. Built-In, Synchronous Step-Down DC/DC Converters
☆GreenOperation Compatible
■GENERAL DESCRIPTION
The XC9235/XC9236/XC9237 series is a group of synchronous-rectification type DC/DC converters with a built-in 0.42Ω
P-channel MOS driver transistor and 0.52ΩN-channel MOS switching transistor, designed to allow the use of ceramic
capacitors. Operating voltage range is from 2.0V to 6.0V (A∼C types), 1.8V to 6.0V (D∼G types). For the D/F types which
have a reference voltage of 0.8V (accuracy: ±2.0%), the output voltage can be set from 0.9V by using two external resistors.
The A/B/C/E/G types have a fixed output voltage from 0.8V to 4.0V in increments of 0.05V (accuracy: ±2.0%). The device
provides a high efficiency, stable power supply with an output current of 600mA to be configured using only a coil and two
capacitors connected externally.
With the built-in oscillator, either 1.2MHz or 3.0MHz can be selected for suiting to your
particular application. As for operation mode, the XC9235 series is PWM control, the XC9236 series is automatic PWM/PFM
switching control and the XC9237 series can be manually switched between the PWM control mode and the automatic
PWM/PFM switching control mode, allowing fast response, low ripple and high efficiency over the full range of loads (from light
load to heavy load).
The soft start and current control functions are internally optimized. During stand-by, all circuits are shutdown to reduce current
consumption to as low as 1.0μA or less. The B/F/G types have a high speed soft-start as fast as 0.25ms 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 1.4V or lower.
The B to G types integrate CL discharge function which enables the electric charge at the output capacitor CL to be discharged
via the internal discharge switch located between the LX and VSS pins. When the devices enter stand-by mode, output voltage
quickly returns to the VSS level as a result of this function.
Four types of package SOT-25, USP-6C, USP-6EL and WLP-5-03 are available.
■APPLICATIONS
●Smart phones / Mobile phones
●Bluetooth
●Mobile devices / terminals
●Portable game consoles
●Digital still cameras / Camcorders
●Note PCs / Tablet PCs
■TYPICAL APPLICATION CIRCUIT
●XC9235/XC9236/XC9237
A/B/C/E/G types (Output Voltage Fixed)
■FEATURES
Driver Transistor Built-In
: 0.42Ω P-ch driver transistor
0.52Ω N-ch switch transistor
Input Voltage
: 2.0V ~ 6.0V (A/B/C types)
1.8V ~ 6.0V (D/E/F/G types)
Output Voltage
: 0.8V ~ 4.0V (Internally set)
0.9V ~ 6.0V (Externally set)
High Efficiency
: 92% (TYP.)*
Output Current
: 600mA
Oscillation Frequency
: 1.2MHz, 3.0MHz (+15%)
Maximum Duty Cycle
: 100%
Control Methods
: PWM (XC9235)
PWM/PFM Auto (XC9236)
PWM/PFM Manual (XC9237)
Function
: Current Limiter Circuit Built-In
(Constant Current & Latching)
CL Discharge (B/C/D/E/F/G types)
High Speed Soft Start (B/F/G type)
Capacitor
: Low ESR Ceramic Capacitor
Operating Ambient Temperature
:-40℃ ~ +85℃
Packages
: SOT-25 (A/B/C types only)
USP-6C
USP-6EL(A/B/C types only)
WLP-5-03(A/B types only)
Environmentally Friendly
: EU RoHS Compliant, Pb Free
* Performance depends on external components and wiring on the PCB.
■TYPICAL PERFORMANCE CHARACTERISTICS
●XC9235/XC9236/XC9237
●Efficiency vs. Output Current（fOSC=1.2MHz, VOUT=1.8V）
D/F types (Output Voltage Externally Set)
100
PWM/PFM Automatic Sw itching Control
90
Efficiency:
EFFI (%)
Efficency:EFFI(%)
80
VIN= 4.2V
70
60
50
PWM Control
VIN= 4.2V
3.6V
2.4V
3.6V
2.4V
40
30
20
10
0
0.1
1
10
100
1000
Output Current:IOUT(mA)
1/34
XC9235/XC9236/XC9237 Series
■PIN CONFIGURATION
Lx
VOUT
5
4
1
2
VIN
VSS
VIN
6
1
Lx
VSS
5
2
VSS
CE/MODE 4
3
VOUT (FB)
VIN
6
1
Lx
VSS
5
2
VSS
CE/MODE 4
3
VOUT
3
CE/MODE
SOT-25
SOT-25
(TOP
VIEW)
(Top View)
USP-6C
(BOTTOM VIEW)
USP-6EL
(BOTTOM VIEW)
* Please short the VSS pin (No. 2 and 5).
* The dissipation pad for the USP-6C package should be solder-plated in
recommended mount pattern and metal masking so as to enhance mounting
strength and heat release. If the pad needs to be connected to other pins, it
should be connected to the VSS (No. 5) pin.
WLP-5-03
(BOTTOM VIEW)
■PIN ASSIGNMENT
2/34
SOT-25
1
2
3
PIN NUMBER
USP-6C/USP-6EL
6
2, 5
4
WLP-5-03
2
3
1
4
3
4
5
1
5
PIN NAME
FUNCTIONS
VIN
VSS
CE / MODE
VOUT
FB
Lx
Power Input
Ground
High Active Enable / Mode Selection Pin
Fixed Output Voltage Pin (A/B/C/E/G types)
Output Voltage Sense Pin (D/F types)
Switching Output
XC9235/XC9236/XC9237
Series
■PRODUCT CLASSIFICATION
●Ordering Information
XC9235①②③④⑤⑥-⑦(*1)
XC9236①②③④⑤⑥-⑦(*1)
*1
XC9237①②③④⑤⑥-⑦( )
DESIGNATOR
①
ITEM
Fixed Output voltage (VOUT)
Functional selection
Adjustable Output voltage (FB)
Functional selection
②③
④
⑤⑥-⑦
Fixed PWM control
PWM / PFM automatic switching control
Fixed PWM control QPWM / PFM automatic switching manual selection
SYMBOL
VIN≧2.0V, No CL discharge, Low speed soft-start
VIN≧2.0V, CL discharge, High speed soft-start
C
VIN≧2.0V, CL discharge, Low speed soft-start
E
VIN≧1.8V, CL discharge, Low speed soft-start
G
VIN≧1.8V, CL discharge, High speed soft-start
D
VIN≧1.8V, CL discharge, Low speed soft-start
F
VIN≧1.8V, CL discharge, High speed soft-start
Output voltage options
e.g. VOUT=2.8V→②=2, ③=8
VOUT=2.85V→②=2, ③=L
0.05V increments: 0.05=A, 0.15=B, 0.25=C, 0.35=D, 0.45=E,
0.55=F, 0.65=H, 0.75=K, 0.85=L, 0.95=M
Reference voltage is fixed in 0.8V
②=0, ③=8
Fixed Output Voltage
(VOUT)
08 ~ 40
Adjustable Output Voltage
(FB)
08
Oscillation Frequency
Packages
(Order Unit)
DESCRIPTION
A
B
C
D
1.2MHz
3.0MHz
MR
SOT-25(*2) (3,000/Reel)
MR-G
SOT-25(*2) (3,000/Reel)
ER
USP-6C (3,000/Reel)
ER-G
USP-6C (3,000/Reel)
4R-G
USP-6EL(*2) (3,000/Reel)
0R-G
WLP-5-03 (*3) (3,000/Reel)
(*1)
The “-G” suffix denotes Halogen and Antimony free as well as being fully EU RoHS compliant.
SOT-25, USP-6EL package are available for the A/B/C series only.
(*3)
WLP-5-03 package is available for the A/B series only.
(*2)
3/34
XC9235/XC9236/XC9237 Series
■BLOCK DIAGRAM
●XC9235 / XC9236 / XC9237
●XC9235 / XC9236 / XC9237
A Series
B/C/E/G Series
●XC9235 / XC9236 / XC9237
D/F Series
NOTE: The signal from CE/MODE Control Logic to PWM/PFM Selector is being fixed to "L" level inside,
and XC9235 series chooses only PWM control.
The signal from CE/MODE Control Logic to PWM/PFM Selector is being fixed to "H" level inside,
and XC9236 series chooses only PWM/PFM automatic switching control.
Diodes inside the circuit are ESD protection diodes and parasitic diodes.
■ABSOLUTE MAXIMUM RATINGS
Ta=25℃
PARAMETER
SYMBOL
RATINGS
UNIT
VIN Pin Voltage
Lx Pin Voltage
VOUT Pin Voltage
FB Pin Voltage
CE / MODE Pin Voltage
Lx Pin Current
SOT-25
USP-6C
Power Dissipation
USP-6EL
WLP-5-03
Operating Ambient Temperature
Storage Temperature
VIN
VLx
VOUT
VFB
VCE
ILx
- 0.3 ~ 6.5
- 0.3 ~ VIN + 0.3
- 0.3 ~ 6.5
- 0.3 ~ 6.5
- 0.3 ~ 6.5
±1500
250
120
120
750
- 40 ~ + 85
- 55 ~ + 125
V
V
V
V
V
mA
4/34
Pd
Topr
Tstg
mW
O
O
C
C
XC9235/XC9236/XC9237
Series
■ELECTRICAL CHARACTERISTICS
XC9235A18Cxx/XC9236A18Cxx/XC9237A18Cxx, VOUT=1.8V, fOSC=1.2MHz, Ta=25℃
PARAMETER
SYMBOL
Output Voltage
VOUT
Operating Voltage Range
VIN
CONDITIONS
When connected to external components,
VIN=VCE=5.0V, IOUT=30mA
Maximum Output Current
IOUTMAX
VIN=VOUT(E)+2.0V, VCE=1.0V,
(*9)
When connected to external components
UVLO Voltage
VUVLO
VCE =VIN, VOUT=0V,
(*1, *11)
Voltage which Lx pin holding “L” level
MIN.
TYP.
MAX.
UNIT
CIRCUIT
1.764
1.800
1.836
V
①
2.0
-
6.0
V
①
600
-
-
mA
①
1.00
1.40
1.78
V
③
Supply Current
IDD
VIN=VCE=5.0V, VOUT=VOUT(E)×1.1V
-
15
33
μA
②
Stand-by Current
ISTB
VIN=5.0V, VCE=0V, VOUT=VOUT(E)×1.1V
-
0
1.0
μA
②
Oscillation Frequency
fOSC
When connected to external components,
VIN=VOUT(E)+2.0V, VCE =1.0V, IOUT=100mA
1020
1200
1380
kHz
①
PFM Switching Current
IPFM
When connected to external components,
(*12)
VIN=VOUT(E)+2.0V, VCE =VIN, IOUT=1mA
120
160
200
mA
①
PFM Duty Limit
DTYLIMIT_PFM
Maximum Duty Cycle
DTYMAX
VIN=VCE=5.0V, VOUT=VOUT(E)×0.9V
Minimum Duty Cycle
DTYMIN
VIN=VCE=5.0V, VOUT=VOUT(E)×1.1V
When connected to external components,
VCE=VIN=VOUT(E)+1.2V, IOUT=100mA
(*3)
VIN=VCE=5.0V, VOUT=0V, ILx=100mA
Efficiency
(*2)
EFFI
Lx SW "H" ON Resistance 1
RLxH
VCE=VIN=(C-1), IOUT=1mA
(*12)
(*3)
200
300
%
①
100
-
-
%
③
-
-
0
%
③
-
92
-
%
①
-
0.35
0.55
Ω
④
Lx SW "H" ON Resistance 2
RLxH
VIN=VCE=3.6V, VOUT=0V, ILx=100mA
-
0.42
0.67
Ω
④
Lx SW "L" ON Resistance 1
RLxL
VIN=VCE=5.0V
(*4)
-
0.45
0.65
Ω
④
Lx SW "L" ON Resistance 2
RLxL
VIN=VCE=3.6V
(*4)
-
0.52
0.77
Ω
-
-
0.01
1.0
μA
⑤
Lx SW "H" Leak Current
(*5)
ILEAKH
VIN=VOUT=5.0V, VCE=0V, Lx=0V
Lx SW "L" Leak Current
(*5)
ILEAKL
VIN=VOUT=5.0V, VCE=0V, Lx=5.0V
(*10)
Current Limit
Output Voltage
Temperature Characteristics
CE "H" Voltage
CE "L" Voltage
(*8)
ILIM
VIN=VCE=5.0V, VOUT=VOUT(E)×0.9V
△VOUT/
IOUT=30mA, -40℃≦Topr≦85℃
(VOUT・△Topr)
VOUT=0V, Applied voltage to VCE,
VCEH
(*11)
Voltage changes Lx to “H” level
VOUT=0V, Applied voltage to VCE ,
VCEL
(*11)
Voltage changes Lx to “L” level
PWM "H" Level Voltage
VPWMH
PWM "L" Level Voltage
VPWML
CE "H" Current
CE "L" Current
ICEH
ICEL
Soft Start Time
tSS
Latch Time
tLAT
Short Protection Threshold
Voltage
VSHORT
When connected to external components,
(*6)
IOUT=1mA , Voltage which oscillation frequency
(*13)
becomes 1020 kHz≦fOSC≦1380kHz
When connected to external components,
(*6)
IOUT=1mA , Voltage which oscillation frequency
(*13)
becomes fOSC＜1020kHz
VIN=VCE=5.0V, VOUT=0V
VIN=5.0V, VCE=0V, VOUT=0V
When connected to external components,
VCE=0V → VIN, IOUT=1mA
VIN=VCE=5.0V, VOUT=0.8×VOUT(E),
(*7)
Short Lx at 1Ω resistance
Sweeping VOUT, VIN=VCE=5.0V, Short Lx at
1Ω resistance, VOUT voltage which Lx becomes
“L” level within 1ms
-
0.01
1.0
μA
⑤
900
1050
1350
mA
⑥
-
±100
-
ppm/℃
①
0.65
-
6.0
V
③
VSS
-
0.25
V
③
-
-
VIN - 1.0
V
①
VIN –
0.25
-
-
V
①
- 0.1
- 0.1
-
0.1
0.1
μA
μA
⑤
⑤
0.5
1.0
2.5
ms
①
1.0
-
20.0
ms
⑦
0.675
0.900
1.150
V
⑦
Test conditions: Unless otherwise stated, VIN=5.0V, VOUT(E)=Nominal Voltage
NOTE:
*1: Including hysteresis operating voltage range.
*2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100
*3: ON resistance (Ω)= (VIN - Lx pin measurement voltage) / 100mA
*4: R&D value
*5: When temperature is high, a current of approximately 10μA (maximum) may leak.
*6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation,
control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3V, and to the PWM
mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH.
*7: Time until it short-circuits VOUT with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.
*8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.
*9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.
If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance.
*10: Current limit denotes the level of detection at peak of coil current.
*11: “H”=VIN~VIN-1.2V, “L”=+0.1V~-0.1V
*12: XC9235 series exclude IPFM and DTYLIMIT_PFM because those are only for the PFM control’s functions.
*13: XC9235/XC9236 series exclude VPWMH and VPWML because those are only for the XC9237 series’ functions.
5/34
XC9235/XC9236/XC9237 Series
■ELECTRICAL CHARACTERISTICS (Continued)
XC9235A18Dxx/XC9236A18Dxx/XC9237A18Dxx, VOUT=1.8V, fOSC=3.0MHz, Ta=25℃
PARAMETER
SYMBOL
Output Voltage
VOUT
Operating Voltage Range
VIN
CONDITIONS
When connected to external components,
VIN=VCE=5.0V, IOUT=30mA
Maximum Output Current
IOUTMAX
VIN=VOUT(E)+2.0V, VCE=1.0V,
(*9)
When connected to external components
UVLO Voltage
VUVLO
VCE=VIN, VOUT=0V,
(*1,*11)
Voltage which Lx pin holding “L” level
MIN.
TYP.
MAX.
UNIT
CIRCUIT
1.764
1.800
1.836
V
①
2.0
-
6.0
V
①
600
-
-
mA
①
1.00
1.40
1.78
V
③
Supply Current
IDD
VIN=VCE=5.0V, VOUT=VOUT(E)×1.1V
-
21
35
μA
②
Stand-by Current
ISTB
VIN=5.0V, VCE=0V, VOUT=VOUT(E)×1.1V
-
0
1.0
μA
②
Oscillation Frequency
fOSC
When connected to external components,
VIN=VOUT(E)+2.0V, VCE=1.0V, IOUT=100mA
2550
3000
3450
kHz
①
PFM Switching Current
IPFM
When connected to external components,
(*12)
VIN=VOUT(E)+2.0V, VCE=VIN, IOUT=1mA
170
220
270
mA
①
PFM Duty Limit
DTYLIMIT_PFM
Maximum Duty Cycle
DTYMAX
VIN=VCE=5.0V, VOUT=VOUT(E)×0.9V
Minimum Duty Cycle
DTYMIN
VIN=VCE=5.0V, VOUT=VOUT(E)×0.1V
When connected to external components,
VCE=VIN＝VOUT(E)+1.2V, IOUT=100mA
(*3)
VIN=VCE=5.0V, VOUT =0V, ILx=100mA
(*3)
VIN=VCE=3.6V, VOUT =0V, ILx=100mA
(*4)
VIN=VCE=5.0V
(*4)
VIN=VCE=3.6V
VIN=VOUT=5.0V, VCE=0V, Lx=0V
VIN=VOUT=5.0V, VCE=0V, Lx=5.0V
(*8)
VIN=VCE=5.0V, VOUT=VOUT(E)×0.9V
Efficiency
(*2)
EFFI
VCE=VIN=(C-1), IOUT=1mA
(*12)
Lx SW "H" ON Resistance 1
RLxH
Lx SW "H" ON Resistance 2
RLxH
Lx SW "L" ON Resistance 1
RLxL
Lx SW "L" ON Resistance 2
RLxL
(*5)
Lx SW "H" Leak Current
ILEAKH
(*5)
Lx SW "L" Leak Current
ILEAKL
(*10)
Current Limit
ILIM
Output Voltage
△VOUT/
IOUT=30mA, -40℃≦Topr≦85℃
Temperature Characteristics (VOUT・△Topr)
VOUT=0V, Applied voltage to VCE,
CE "H" Voltage
VCEH
(*11)
Voltage changes Lx to “H” level
VOUT=0V, Applied voltage to VCE,
CE "L" Voltage
VCEL
(*11)
Voltage changes Lx to “L” level
PWM "H" Level Voltage
VPWMH
PWM "L" Level Voltage
VPWML
CE "H" Current
CE "L" Current
ICEH
ICEL
Soft Start Time
tSS
Latch Time
tLAT
Short Protection Threshold
Voltage
VSHORT
When connected to external components,
(*6)
IOUT=1mA , Voltage which oscillation frequency
(*13)
becomes 2550kHz≦fOSC≦3450kHz
When connected to external components,
(*6)
IOUT=1mA , Voltage which oscillation frequency
(*13)
becomes fOSC＜2550kHz
VIN=VCE=5.0V, VOUT=0V
VIN=5.0V, VCE=0V, VOUT=0V
When connected to external components,
VCE=0V → VIN, IOUT=1mA
VIN=VCE=5.0V, VOUT=0.8×VOUT(E),
(*7)
Short Lx at 1Ω resistance
Sweeping VOUT, VIN=VCE=5.0V, Short Lx at
1Ω resistance, VOUT voltage which Lx becomes
“L” level within 1ms
-
200
300
%
①
100
-
-
%
③
-
-
0
%
③
-
86
-
%
①
900
0.35
0.42
0.45
0.52
0.01
0.01
1050
0.55
0.67
0.65
0.77
1.0
1.0
1350
Ω
Ω
Ω
Ω
μA
μA
mA
④
④
⑤
⑤
⑥
-
±100
-
ppm/℃
①
0.65
-
6.0
V
③
VSS
-
0.25
V
③
-
-
VIN - 1.0
V
①
VIN –
0.25
-
-
V
①
- 0.1
- 0.1
-
0.1
0.1
μA
μA
⑤
⑤
0.5
0.9
2.5
ms
①
1.0
-
20
ms
⑦
0.675
0.900
1.150
V
⑦
Test conditions: Unless otherwise stated, VIN=5.0V, VOUT(E)=Nominal Voltage
NOTE:
*1: Including hysteresis operating voltage range.
*2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100
*3: ON resistance (Ω)= (VIN - Lx pin measurement voltage) / 100mA
*4: R&D value
*5: When temperature is high, a current of approximately 10μA (maximum) may leak.
*6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation,
control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3V, and to the PWM
mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH.
*7: Time until it short-circuits VOUT with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.
*8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.
*9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.
If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance.
*10: Current limit denotes the level of detection at peak of coil current.
*11: “H”=VIN~VIN-1.2V, “L”=+0.1V~-0.1V
*12: XC9235 series exclude IPFM and DTYLIMIT_PFM because those are only for the PFM control’s functions.
*13: XC9235/XC9236 series exclude VPWMH and VPWML because those are only for the XC9237 series’ functions.
6/34
XC9235/XC9236/XC9237
Series
■ELECTRICAL CHARACTERISTICS (Continued)
XC9235B(C)(E)(G)18Cxx/XC9236B(C)(E)(G)18Cxx/XC9237B(C)(E)(G)18Cxx, VOUT=1.8V, fOSC=1.2MHz, Ta=25℃
PARAMETER
SYMBOL
Output Voltage
VOUT
Operating Voltage Range (B/C series)
Operating Voltage Range (E/G series)
VIN
Maximum Output Current
IOUTMAX
UVLO Voltage
VUVLO
Supply Current
Stand-by Current
IDD
ISTB
Oscillation Frequency
fOSC
PFM Switching Current
IPFM
CONDITIONS
When connected to external components,
VIN=VCE=5.0V, IOUT=30mA
VIN=VOUT(E)+2.0V, VCE=1.0V,
(*9)
When connected to external components
(*14)
VCE =VIN, VOUT=VOUT(E)×0.5V
(*1, *11)
Voltage which Lx pin holding “L” level
VIN=VCE=5.0V, VOUT=VOUT(E)×1.1V
VIN=5.0V, VCE=0V, VOUT=VOUT(E)×1.1V
When connected to external components,
VIN=VOUT(E)+2.0V, VCE =1.0V, IOUT=100mA
When connected to external components,
(*12)
VIN=VOUT(E)+2.0V, VCE =VIN, IOUT=1mA
(*12)
VCE=VIN=(C-1), IOUT=1mA
PFM Duty Limit
DTYLIMIT_PFM
Maximum Duty Cycle
DTYMAX
VIN=VCE=5.0V, VOUT=VOUT(E)×0.9V
Minimum Duty Cycle
DTYMIN
MIN.
TYP.
MAX.
UNIT
CIRCUIT
1.764
1.800
1.836
V
①
2.0
1.8
-
6.0
6.0
V
①
600
-
-
mA
①
1.00
1.40
1.78
V
③
-
15
0
33
1.0
μA
μA
②
②
1020
1200
1380
kHz
①
120
160
200
mA
①
200
300
%
①
100
-
-
%
③
-
-
0
%
③
-
92
-
%
①
-
0.35
0.55
Ω
④
(*3)
-
0.42
0.67
Ω
④
-
0.45
0.65
Ω
④
Lx SW "H" ON Resistance 1
RLxH
VIN=VCE=5.0V, VOUT=VOUT(E)×1.1V
When connected to external components,
VCE=VIN=VOUT(E)+1.2V, IOUT=100mA
(*3)
VIN=VCE=5.0V, VOUT (E)×0.9V , ILx=100mA
Lx SW "H" ON Resistance 2
RLxH
VIN=VCE=3.6V, VOUT (E)×0.9V , ILx=100mA
Lx SW "L" ON Resistance 1
RLxL
VIN=VCE=5.0V
(*4)
RLxL
VIN=VCE=3.6V
(*4)
-
0.52
0.77
Ω
-
ILEAKH
VIN=VOUT=5.0V, VCE=0V, Lx=0V
-
0.01
1.0
μA
⑤
900
1050
1350
mA
⑥
-
±100
-
ppm/℃
①
0.65
-
6.0
V
③
VSS
-
0.25
V
③
-
-
VIN - 1.0
V
①
VIN –
0.25
-
-
V
①
- 0.1
- 0.1
-
0.1
0.1
μA
μA
⑤
⑤
-
0.25
0.40
ms
①
0.5
1.0
2.5
ms
①
1.0
-
20.0
ms
⑦
0.675
0.900
1.150
V
⑦
0.338
0.450
0.563
V
⑦
200
300
450
Ω
⑧
Efficiency
(*2)
EFFI
Lx SW "L" ON Resistance 2
Lx SW "H" Leak Current
(*5)
(*10)
Current Limit
Output Voltage
Temperature Characteristics
CE "H" Voltage
CE "L" Voltage
(*8)
ILIM
VIN=VCE=5.0V, VOUT=VOUT(E)×0.9V
△VOUT/
I =30mA, -40℃≦Topr≦85℃
(VOUT・△Topr) OUT
VOUT= VOUT(E)×0.9V, Applied voltage to VCE,
VCEH
(*11)
Voltage changes Lx to “H” level
VOUT= VOUT(E)×0.9V, Applied voltage to VCE ,
VCEL
(*11)
Voltage changes Lx to “L” level
PWM "H" Level Voltage
VPWMH
PWM "L" Level Voltage
VPWML
CE "H" Current
CE "L" Current
ICEH
ICEL
Soft Start Time (B/G Series)
tSS
Soft Start Time (C/E Series)
tSS
Latch Time
tLAT
Short Protection Threshold
Voltage (B/C Series)
VSHORT
Short Protection Threshold
Voltage (E/G Series)
VSHORT
CL Discharge
RDCHG
When connected to external components,
(*6)
IOUT=1mA , Voltage which oscillation frequency
(*13)
becomes 1020 kHz≦fOSC≦1380kHz
When connected to external components,
(*6)
IOUT=1mA , Voltage which oscillation frequency
(*13)
becomes fOSC＜1020kHz
VIN=VCE=5.0V, VOUT= VOUT(E)×0.9V
VIN=5.0V, VCE=0V, VOUT= VOUT(E)×0.9V
When connected to external components,
VCE=0V → VIN, IOUT=1mA
When connected to external components,
VCE=0V → VIN, IOUT=1mA
VIN=VCE=5.0V, VOUT=0.8×VOUT(E),
(*7)
Short Lx at 1Ω resistance
Sweeping VOUT, VIN=VCE=5.0V, Short Lx at
1Ω resistance, VOUT voltage which Lx becomes
“L” level within 1ms
(*11)
VIN=VCE=5.0V, The VOUT at Lx=”Low"
while
decreasing VOUT from VOUT (E)×0.4V
VIN=5.0V, LX=5.0V, VCE=0V, VOUT=open
Test conditions: Unless otherwise stated, VIN=5.0V, VOUT(E)=Nominal Voltage, applied voltage sequence is VOUT→VIN→VCE
NOTE:
*1: Including hysteresis operating voltage range.
*2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100
*3: ON resistance (Ω)= (VIN - Lx pin measurement voltage) / 100mA
*4: R&D value
*5: When temperature is high, a current of approximately 10μA (maximum) may leak.
*6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation,
control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3V, and to the PWM
mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH.
*7: Time until it short-circuits VOUT with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.
*8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.
*9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.
If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance.
*10: Current limit denotes the level of detection at peak of coil current.
*11: “H”=VIN~VIN-1.2V, “L”=+0.1V~-0.1V
*12: XC9235 series exclude IPFM and DTYLIMIT_PFM because those are only for the PFM control’s functions.
*13: XC9235/XC9236 series exclude VPWMH and VPWML because those are only for the XC9237 series’ functions.
*14: VIN is applied when VOUT (E) x 0.5V becomes more than VIN.
7/34
XC9235/XC9236/XC9237 Series
■ELECTRICAL CHARACTERISTICS (Continued)
XC9235B(C)(E)(G)18Dxx/XC9236B(C)(E)(G)18Dxx/XC9237B(C)(E)(G)18Dxx, VOUT=1.8V, fOSC=3.0MHz, Ta=25℃
PARAMETER
SYMBOL
Output Voltage
VOUT
Operating Voltage Range (B/C series)
Operating Voltage Range (E/G series)
VIN
Maximum Output Current
IOUTMAX
UVLO Voltage
VUVLO
Supply Current
Stand-by Current
IDD
ISTB
Oscillation Frequency
fOSC
PFM Switching Current
IPFM
CONDITIONS
When connected to external components,
VIN=VCE=5.0V, IOUT=30mA
VIN=VOUT(E)+2.0V, VCE=1.0V,
(*9)
When connected to external components
(*14)
,
VCE=VIN, VOUT=VOUT(E)×0.5V
(*1,*11)
Voltage which Lx pin holding “L” level
VIN=VCE=5.0V, VOUT=VOUT(E)×1.1V
VIN=5.0V, VCE=0V, VOUT=VOUT(E)×1.1V
When connected to external components,
VIN=VOUT(E)+2.0V, VCE=1.0V, IOUT=100mA
When connected to external components,
(*12)
VIN=VOUT(E)+2.0V, VCE=VIN, IOUT=1mA
(*12)
VCE=VIN=(C-1), IOUT=1mA
PFM Duty Limit
DTYLIMIT_PFM
Maximum Duty Cycle
DTYMAX
VIN=VCE=5.0V, VOUT=VOUT(E)×0.9V
Minimum Duty Cycle
DTYMIN
VIN=VCE=5.0V, VOUT=VOUT(E)×0.1V
When connected to external components,
VCE=VIN＝VOUT(E)+1.2V, IOUT=100mA
(*3)
VIN=VCE=5.0V, VOUT=VOUT(E)×0.9V, ILx=100mA
(*3)
VIN=VCE=3.6V, VOUT=VOUT(E)×0.9V, ILx=100mA
(*4)
VIN=VCE=5.0V
(*4)
VIN=VCE=3.6V
VIN=VOUT=5.0V, VCE=0V, Lx=0V
(*8)
VIN=VCE=5.0V, VOUT=VOUT(E)×0.9V
(*2)
Efficiency
Lx SW "H" ON Resistance 1
Lx SW "H" ON Resistance 2
Lx SW "L" ON Resistance 1
Lx SW "L" ON Resistance 2
(*5)
Lx SW "H" Leak Current
(*10)
Current Limit
Output Voltage
Temperature Characteristics
CE "H" Voltage
CE "L" Voltage
EFFI
RLxH
RLxH
RLxL
RLxL
ILEAKH
ILIM
△VOUT/
I =30mA, -40℃≦Topr≦85℃
(VOUT・△Topr) OUT
VOUT=VOUT(E)×0.9V, Applied voltage to VCE,
VCEH
(*11)
Voltage changes Lx to “H” level
VOUT=VOUT(E)×0.9V, Applied voltage to VCE,
VCEL
(*11)
Voltage changes Lx to “L” level
When connected to external components,
(*6)
IOUT=1mA , Voltage which oscillation frequency
(*13)
becomes 2550kHz≦fOSC≦3450kHz
PWM "H" Level Voltage
VPWMH
PWM "L" Level Voltage
VPWML
CE "H" Current
CE "L" Current
ICEH
ICEL
Soft Start Time (B/G Series)
tSS
Soft Start Time (C/E Series)
tSS
Latch Time
tLAT
Short Protection Threshold
Voltage (B/C Series)
VSHORT
Short Protection Threshold
Voltage (E/G Series)
VSHORT
VIN=VCE=5.0V, The VOUT at Lx=”Low"
decreasing VOUT from VOUT (E)×0.4V
CL Discharge
RDCHG
VIN=5.0V, LX=5.0V, VCE=0V, VOUT=open
When connected to external components,
(*6)
IOUT=1mA , Voltage which oscillation frequency
(*13)
becomes fOSC＜2550kHz
VIN=VCE=5.0V, VOUT=VOUT(E)×0.9V
VIN=5.0V, VCE=0V, VOUT=VOUT(E)×0.9V
When connected to external components,
VCE=0V → VIN, IOUT=1mA
When connected to external components,
VCE=0V → VIN, IOUT=1mA
VIN=VCE=5.0V, VOUT=0.8×VOUT(E),
(*7)
Short Lx at 1Ω resistance
Sweeping VOUT, VIN=VCE=5.0V, Short Lx at
1Ω resistance, VOUT voltage which Lx becomes
“L” level within 1ms
(*11)
while
MIN.
TYP.
MAX.
UNIT
CIRCUIT
1.764
1.800
1.836
V
①
2.0
1.8
-
6.0
6.0
V
①
600
-
-
mA
①
1.00
1.40
1.78
V
③
-
21
0
35
1.0
μA
μA
②
②
2550
3000
3450
kHz
①
170
220
270
mA
①
-
200
300
%
①
100
-
-
%
③
-
-
0
%
③
-
86
-
%
①
900
0.35
0.42
0.45
0.52
0.01
1050
0.55
0.67
0.65
0.77
1.0
1350
Ω
Ω
Ω
Ω
μA
mA
④
④
⑤
⑥
-
±100
-
ppm/℃
①
0.65
-
6.0
V
③
VSS
-
0.25
V
③
-
-
VIN - 1.0
V
①
VIN –
0.25
-
-
V
①
- 0.1
- 0.1
-
0.1
0.1
μA
μA
⑤
⑤
-
0.32
0.50
ms
①
0.5
0.9
2.5
ms
①
1.0
-
20
ms
⑦
0.675
0.900
1.150
V
⑦
0.338
0.450
0.563
V
⑦
200
300
450
Ω
⑧
Test conditions: Unless otherwise stated, VIN=5.0V, VOUT(E)=Nominal Voltage, applied voltage sequence is VOUT→VIN→VCE
NOTE:
*1: Including hysteresis operating voltage range.
*2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100
*3: ON resistance (Ω)= (VIN - Lx pin measurement voltage) / 100mA
*4: R&D value
*5: When temperature is high, a current of approximately 10μA (maximum) may leak.
*6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation,
control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3V, and to the PWM
mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH.
*7: Time until it short-circuits VOUT with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.
*8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.
*9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.
If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance.
*10: Current limit denotes the level of detection at peak of coil current.
*11: “H”=VIN~VIN-1.2V, “L”=+0.1V~-0.1V
*12: XC9235 series exclude IPFM and DTYLIMIT_PFM because those are only for the PFM control’s functions.
*13: XC9235/XC9236 series exclude VPWMH and VPWML because those are only for the XC9237 series’ functions.
*14: VIN is applied when VOUT (E) x 0.5V becomes more than VIN.
8/34
XC9235/XC9236/XC9237
Series
■ELECTRICAL CHARACTERISTICS (Continued)
XC9235D(F)08Cxx/XC9236D(F)08Cxx/XC9237D(F)08Cxx, FB Type, fOSC=1.2MHz, Ta=25℃
PARAMETER
SYMBOL
CONDITIONS
(*11)
FB Voltage
VFB
Operating Voltage Range
VIN
Maximum Output Current
IOUTMAX
UVLO Voltage
VUVLO
Supply Current
Stand-by Current
IDD
ISTB
Oscillation Frequency
fOSC
PFM Switching Current
IPFM
VIN = VCE =5.0V, The VFB at Lx=”High"
decreasing FB pin voltage from 0.9V.
while
VIN=3.2V, VCE=1.0V
(*9)
When connected to external components
VCE = VIN , VFB = 0.4V,
(*1,*11)
Voltage which Lx pin holding “L” level
VIN =VCE=5.0V, VFB= 0.88V
VIN =5.0V, VCE=0V, VFB= 0.88V
When connected to external components,
VIN = 3.2V, VCE=1.0V, IOUT=100mA
When connected to external components,
(*12)
VIN =3.2V, VCE = VIN , IOUT=1mA
(*12)
VCE= VIN =2.0V IOUT=1mA
PFM Duty Limit
DTYLIMIT_PFM
Maximum Duty Cycle
DTYMAX
VIN = VCE =5.0V, VFB = 0.72V
Minimum Duty Cycle
DTYMIN
VIN = VCE =5.0V, VFB = 0.88V
When connected to external components,
VCE = VIN ＝ 2.4V, IOUT = 100mA
(*3)
VIN = VCE = 5.0V, VFB = 0.72V,ILX = 100mA
(*3)
VIN = VCE = 3.6V, VFB = 0.72V,ILX = 100mA
(*4)
VIN = VCE = 5.0V
(*4)
VIN = VCE = 3.6V
VIN = VFB = 5.0V, VCE = 0V, LX= 0V
(*8)
VIN = VCE= 5.0V, VFB = 0.72V
IOUT =30mA
-40℃≦Topr≦85℃
VFB =0.72V, Applied voltage to VCE,
(*11)
Voltage changes Lx to “H” level
VFB =0.72V, Applied voltage to VCE,
(*11)
Voltage changes Lx to “L” level
When connected to external components,
(*6)
IOUT=1mA , Voltage which oscillation frequency
(*13)
becomes 1020kHz≦fOSC≦1380kHz
When connected to external components,
(*6)
IOUT=1mA , Voltage which oscillation frequency
(*13)
becomes fOSC＜1020kHz
VIN = VCE =5.0V, VFB =0.72V
VIN =5.0V, VCE = 0V, VFB =0.72V
When connected to external components,
VCE = 0V → VIN , IOUT=1mA
VIN=VCE=5.0V, VFB=0.64, Short Lx at 1Ω
(*7)
resistance
(*11)
while
VIN = VCE =5.0V, The VFB at Lx=”Low"
decreasing FB pin voltage from 0.4V.
Efficiency
(*2)
EFFI
Lx SW "H" ON Resistance 1
Lx SW "H" ON Resistance 2
Lx SW "L" ON Resistance 1
Lx SW "L" ON Resistance 2
(*5)
Lx SW "H" Leak Current
(*10)
Current Limit
Output Voltage
Temperature Characteristics
RLｘH
RLｘH
RLｘL
RLｘL
ILEAKH
ILIM
△VOUT/
(VOUT・△Topr)
CE "H" Voltage
VCEH
CE "L" Voltage
VCEL
PWM "H" Level Voltage
VPWMH
PWM "L" Level Voltage
VPWML
CE "H" Current
CE "L" Current
Soft Start Time (D series)
Soft Start Time (F series)
ICEH
ICEL
Latch Time
tLAT
Short Protection Threshold
Voltage
VSHORT
CL Discharge
RDCHG
tSS
VIN = 5.0V ,LX = 5.0V, VCE = 0V, VFB= open
MIN.
TYP.
MAX.
UNIT
CIRCUIT
0.784
0.800
0.816
V
③
1.8
-
6.0
V
①
600
-
-
mA
①
1.00
1.40
1.78
V
③
-
15
0
1.0
μA
μA
②
②
1020
1200
1380
kHz
①
120
160
200
mA
①
200
300
%
①
100
-
-
%
③
-
-
0
%
③
-
92
-
%
①
900
0.35
0.42
0.45
0.52
0.01
1050
0.55
0.67
0.65
0.77
1.0
1350
Ω
Ω
Ω
Ω
μA
mA
④
④
⑨
⑥
-
±100
-
ppm/ ℃
①
0.65
-
6.0
V
③
VSS
-
0.25
V
③
-
-
VIN - 1.0
V
①
VIN 0.25
-
-
V
①
- 0.1
- 0.1
0.5
-
1.0
0.25
0.1
0.1
2.5
0.40
μA
μA
⑤
⑤
ms
①
1.0
-
20.0
ms
⑦
0.15
0.200
0.25
V
⑦
200
300
450
Ω
⑧
Test conditions: VOUT=1.2V when the external components are connected. Unless otherwise stated, VIN=5.0V, VOUT(E)=Nominal Voltage, applied voltage sequence is
VOUT→VIN→VCE
NOTE:
*1: Including hysteresis operating voltage range.
*2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100
*3: ON resistance (Ω)= (VIN - Lx pin measurement voltage) / 100mA
*4: R&D value
*5: When temperature is high, a current of approximately 10μA (maximum) may leak.
*6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation,
control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3V, and to the PWM
mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH.
*7: Time until it short-circuits VFB with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.
*8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.
*9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.
If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance.
*10: Current limit denotes the level of detection at peak of coil current.
*11: “H”=VIN~VIN-1.2V, “L”=+0.1V~-0.1V
*12: XC9235 series exclude IPFM and DTYLIMIT_PFM because those are only for the PFM control’s functions.
*13: XC9235/XC9236 series exclude VPWMH and VPWML because those are only for the XC9237 series’ functions.
9/34
XC9235/XC9236/XC9237 Series
■ELECTRICAL CHARACTERISTICS (Continued)
XC9235D(F)08Dxx/XC9236D(F)08Dxx/XC9237D(F)08Dxx, FB, fOSC=3.0MHz, Ta=25℃
PARAMETER
SYMBOL
FB Voltage
VFB
Operating Voltage Range
VIN
CONDITIONS
(*11)
VIN = VCE =5.0V, The VFB at Lx=”High"
decreasing FB pin voltage from 0.9V.
while
Maximum Output Current
IOUTMAX
VIN=3.2V, VCE=1.0V
(*9)
When connected to external components
UVLO Voltage
VUVLO
VCE = VIN , VFB = 0.4V ,
(*1, *11)
Voltage which Lx pin holding “L” level
MIN.
TYP.
MAX.
UNIT
CIRCUIT
0.784
0.800
0.816
V
③
1.8
-
6.0
V
①
600
-
-
mA
①
1.00
1.40
1.78
V
③
Supply Current
IDD
VIN =VCE=5.0V, VFB= 0.88V
-
21
35
μA
②
Stand-by Current
ISTB
-
0
1.0
μA
②
Oscillation Frequency
fOSC
2550
3000
3450
kHz
①
PFM Switching Current
IPFM
VIN =5.0V, VCE=0V, VFB= 0.88V
When connected to external components,
VIN = 3.2V, VCE=1.0V, IOUT=100mA
When connected to external components,
(*12)
VIN =3.2V, VCE = VIN , IOUT=1mA
170
220
270
mA
①
(*12)
PFM Duty Limit
DTYLIMIT_PFM
Maximum Duty Cycle
DTYMAX
VIN = VCE =5.0V, VFB = 0.72V
Minimum Duty Cycle
DTYMIN
VIN = VCE =5.0V, VFB = 0.88V
When connected to external components,
VCE = VIN ＝ 2.4V, IOUT = 100mA
(*3)
VIN = VCE = 5.0V, VFB = 0.72V,ILX = 100mA
(*3)
VIN = VCE = 3.6V, VFB = 0.72V,ILX = 100mA
(*4)
VIN = VCE = 5.0V
(*4)
VIN = VCE = 3.6V
VIN = VFB = 5.0V, VCE = 0V, LX= 0V
(*8)
VIN = VCE= 5.0V, VFB = 0.72V
IOUT =30mA
-40℃≦Topr≦85℃
VFB =0.72V , VCE,
(*11)
Voltage changes Lx to “H” level
VFB =0.72V, VCE,
(*11)
Voltage changes Lx to “L” level
When connected to external components,
(*6)
IOUT = 1mA , Voltage which oscillation frequency
(*13)
becomes 2550kHz≦fOSC≦3450kHz
When connected to external components,
(*6)
IOUT = 1mA , Voltage which oscillation frequency
(*13)
becomes fOSC＜2550kHz
VIN = VCE =5.0V, VFB =0.72V
VIN =5.0V, VCE = 0V, VFB =0.72V
When connected to external components,
VCE = 0V → VIN , IOUT=1mA
VIN = VCE = 5.0V, VFB = 0.64,
(*7)
Short Lx at 1Ω resistance
(*11)
VIN = VCE =5.0V, The VFB at Lx=”Low"
while
decreasing FB pin voltage from 0.4V.
Efficiency
(*2)
EFFI
Lx SW "H" ON Resistance 1
Lx SW "H" ON Resistance 2
Lx SW "L" ON Resistance 1
Lx SW "L" ON Resistance 2
(*5)
Lx SW "H" Leak Current
(*10)
Current Limit
Output Voltage
Temperature Characteristics
RLｘH
RLｘH
RLｘL
RLｘL
ILEAKH
ILIM
△VOUT/
(VOUT・△Topr)
CE "H" Voltage
VCEH
CE "L" Voltage
VCEL
PWM "H" Level Voltage
VPWMH
PWM "L" Level Voltage
VPWML
CE "H" Current
CE "L" Current
Soft Start Time (D series)
Soft Start Time (F series)
ICEH
ICEL
Latch Time
tLAT
Short Protection Threshold
Voltage
VSHORT
CL Discharge
RDCHG
tSS
VCE= VIN =2.2V IOUT=1mA
VIN = 5.0V ,LX = 5.0V ,VCE = 0V ,VFB= open
200
300
%
①
100
-
-
%
③
-
-
0
%
③
-
86
-
%
①
900
0.35
0.42
0.45
0.52
0.01
1050
0.55
0.67
0.65
0.77
1.0
1350
Ω
Ω
Ω
Ω
μA
mA
④
④
⑨
⑥
-
±100
-
ppm/ ℃
①
0.65
-
6.0
V
③
VSS
-
0.25
V
③
-
-
VIN - 1.0
V
①
VIN 0.25
-
-
V
①
- 0.1
- 0.1
0.5
-
1.0
0.25
0.1
0.1
2.5
0.40
μA
μA
⑤
⑤
ms
①
1.0
-
20.0
ms
⑦
0.15
0.200
0.25
V
⑦
200
300
450
Ω
⑧
Test conditions: VOUT=1.2V when the external components are connected. Unless otherwise stated, VIN=5.0V, VOUT(E)=Nominal Voltage, applied voltage sequence is
VOUT→VIN→VCE
NOTE:
*1: Including hysteresis operating voltage range.
*2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100
*3: ON resistance (Ω)= (VIN - Lx pin measurement voltage) / 100mA
*4: R&D value
*5: When temperature is high, a current of approximately 10μA (maximum) may leak.
*6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation,
control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3V, and to the PWM
mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH.
*7: Time until it short-circuits VFB with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.
*8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.
*9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.
If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance.
*10: Current limit denotes the level of detection at peak of coil current.
*11: “H”=VIN~VIN-1.2V, “L”=+0.1V~-0.1V
*12: XC9235 series exclude IPFM and DTYLIMIT_PFM because those are only for the PFM control’s functions.
*13: XC9235/XC9236 series exclude VPWMH and VPWML because those are only for the XC9237 series’ functions.
10/34
XC9235/XC9236/XC9237
Series
■ELECTRICAL CHARACTERISTICS (Continued)
●PFM Switching Current (IPFM) by Oscillation Frequency and Setting Voltage
(mA)
SETTING VOLTAGE
VOUT(E) ≦1.2V
1.2V＜VOUT(E) ≦1.75V
1.8V≦VOUT(E)
MIN.
1.2MHz
TYP.
MAX.
140
130
120
180
170
160
240
220
200
MIN.
3.0MHz
TYP.
MAX.
190
180
170
260
240
220
350
300
270
●Input Voltage (VIN) for Measuring PFM Duty Limit (DTYLIMIT_PFM)
fOSC
C-1
1.2MHz
VOUT(E)+0.5V
3.0MHz
VOUT(E)+1.0V
Minimum operating voltage is 2.0V.
ex.) Although when VOUT(E) is 1.2V and fOSC is 1.2MHz, (C-1) should be 1.7V, (C-1) becomes 2.0V for the minimum operating voltage 2.0V.
●Soft-Start Time, Setting Voltage（XC9235B(G)/XC9236B(G)/XC9237B(G) Series only）
SERIES
XC9235B(G)/XC9237B(G)
XC9236B(G)
XC9235B(G)/
XC9236B(G)/XC9237B(G)
(μs)
fOSC
SETTING VOLTAGE
MIN.
TYP.
MAX.
1.2MHz
1.2MHz
0.8≦V OUT(E)
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