XC9235/XC9236/XC9237
Series
600mA Driver Tr. Built-In, Synchronous Step-Down DC/DC Converters
ETR0514-016
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 0.52Ω
N-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 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 C
L
discharge function which enables the electric charge at the output capacitor C
L
to be discharged
via the internal discharge switch located between the L
X
and V
SS
pins. When the devices enter stand-by mode, output voltage
quickly returns to the V
SS
level as a result of this function.
Four types of package SOT-25, USP-6C, USP-6EL and WLP-5-03 are available.
■GENERAL
DESCRIPTION
☆GreenOperation
Compatible
■APPLICATIONS
●Smart
phones / Mobile phones
●Bluetooth
●Mobile
devices / terminals
●Portable
game consoles
●Digital
still cameras / Camcorders
●Note
PCs / Tablet PCs
■FEATURES
: 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)
C
L
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
/G
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.
Driver Transistor Built-In
■TYPICAL
APPLICATION CIRCUIT
●XC9235/XC9236/XC9237
●
/
/
A/B/C/E/G
,
types (Output Voltage Fixed)
, ,
,
シリ ズ(出力電圧固定品)
V
OUT
600mA
L
Lx
VSS
V
IN
V
IN
VSS
CE/
MODE
C
L
(ceramic)
C
IN
(ceramic)
CE/MODE
VOUT
■TYPICAL
PERFORMANCE CHARACTERISTICS
●XC9235/XC9236/XC9237
●XC9235/9236/9237
●Efficiency
vs. Output Current (f
OSC
=1.2MHz, V
OUT
=1.8V)
100
90
V
IN
V
IN
VSS
VSS
CE/
MODE
PWM/PFM Automatic Sw itching Control
●
/
D/F types (Output
/
Voltage Externally Set)
D,Fシリーズ(出力電圧外部設定品)
,
シリ
ズ(出力電圧外部設定品)
L
L
Lx
Lx
VSS
VSS
V
IN
V
IN
C
IN
C
IN
(ceramic)
CE/MODE
Efficiency: EFFI (%)
Efficency:EFFI(%)
V
OUT
V
OUT
600mA
600mA
RFB1
RFB1
80
70
60
50
40
30
20
10
0
0.1
1
10
100
1000
Output Current:IOUT(mA)
2.4V
VIN= 4.2V
3.6V
PWM Control
VIN= 4.2V
3.6V
2.4V
C
L
(ceramic)
CFB
FB
RFB2
1/40
XC9235/XC9236/XC9237
Series
■BLOCK
DIAGRAM
●XC9235
/ XC9236 / XC9237 A Series
Phase
Compensation
CFB
R2
Error Amp.
FB
R1
PWM
Comparator
●XC9235
/ XC9236 / XC9237 B/C/E/G
Phase
Compensation
CFB
R2
Error Amp.
FB
R1
PWM
Comparator
VOUT
Current Feedback
Current Limit
Synch
Buffer
Drive
VOUT
Lx
VIN
Current Feedback
Current Limit
Synch
Buffer
Drive
Logic
VSHORT
Logic
VSHORT
Lx
VIN
Vref with
Soft Start,
CE
PWM/PFM
Selector
UVLO Cmp
Ramp Wave
Generator
OSC
CE/MODE
Control
Logic
Vref with
Soft Start,
CE
PWM/PFM
Selector
CE/
UVLO Cmp
VSS
R3
UVLO
VSS
CE/MODE
R3
UVLO
Ramp Wave
Generator
OSC
CE/MODE
Control
Logic
R4
R4
CE/MODE
●XC9235
/ XC9236 / XC9237 D/F Series
Phase
Compensation
Error Amp.
FB
Current Feedback
Current Limit
PWM
Comparator
FB
Logic
VSHORT
Synch
Buffer
Drive
Lx
VIN
Vref with
Soft Start,
CE
PWM/PFM
Selector
CE/
UVLO Cmp
VSS
R3
UVLO
Ramp Wave
Generator
OSC
CE/MODE
Control
Logic
R4
CE/MODE
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.
2/33
XC9235/XC9236/XC9237
Series
■PRODUCT
CLASSIFICATION
●Ordering
Information
XC9235①②③④⑤⑥-⑦
(
*1
)
XC9236①②③④⑤⑥-⑦
(
*1
)
XC9237①②③④⑤⑥-⑦
(
*1
)
DESIGNATOR
ITEM
Fixed PWM control
PWM / PFM automatic switching control
Fixed PWM control
PWM
/ PFM automatic switching manual selection
SYMBOL
A
B
Fixed Output voltage (V
OUT
)
Functional selection
①
C
E
G
Adjustable Output voltage (FB)
Functional selection
D
F
DESCRIPTION
V
IN
≧2.0V,
No C
L
discharge, Low speed soft-start
V
IN
≧2.0V,
C
L
discharge, High speed soft-start
V
IN
≧2.0V,
C
L
discharge, Low speed soft-start
V
IN
≧1.8V,
C
L
discharge, Low speed soft-start
V
IN
≧1.8V,
C
L
discharge, High speed soft-start
V
IN
≧1.8V,
C
L
discharge, Low speed soft-start
V
IN
≧1.8V,
C
L
discharge, High speed soft-start
Output voltage options
e.g. V
OUT
=2.8V→②=2,
③=8
V
OUT
=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
1.2MHz
3.0MHz
SOT-25
(*2)
(3,000pcs/Reel)
SOT-25
(*2)
(3,000pcs/Reel)
USP-6C (3,000pcs/Reel)
USP-6C (3,000pcs/Reel)
USP-6EL
(*4)
(3,000pcs/Reel)
WLP-5-03
(*3)
(3,000pcs/Reel)
Fixed Output Voltage (V
OUT
)
②③
Adjustable Output Voltage
(FB)
④
Oscillation Frequency
08 ~ 40
08
C
D
MR
MR-G
⑤⑥-⑦
Packages
(Order Unit)
ER
ER-G
4R-G
0R-G
(*1)
(*2)
The “-G” suffix denotes Halogen and Antimony free as well as being fully EU RoHS compliant.
SOT-25 package are available for the A/B/C series only.
(*3)
WLP-5-03 package is available for the A/B series only.
(*4)
USP-6EL package are available for the A/B/C/G series only.
3/33
XC9235/XC9236/XC9237
Series
■PIN
CONFIGURATION
Lx
VOUT
5
4
VIN
VSS
CE/MODE
6
5
4
1
2
3
Lx
VSS
VOUT (FB)
VIN
VSS
CE/MODE
6
5
4
1
2
3
Lx
VSS
VOUT
1
VIN
2
VSS
3
CE/MODE
USP-6C
(BOTTOM VIEW)
SOT-25
(Top View)
USP-6EL
(BOTTOM VIEW)
CE/MODE 1
5
V
IN
2
4 V
OUT
Lx
3 V
SS
* Please short the V
SS
pin (No. 2 and 5).
* The dissipation pad for the USP-6C/USP-6EL packages should be solder-
plated in recommended mount pattern and metal masking so as to enhance
mounting strength and heat release. We recommend keeping the dissipation pas
electrically isolated from the other Pins. If the pad needs to be connected to other
pins, it should be connected to the V
SS
(No. 5) pin.
WLP-5-03
WLP-5-01
(BOTTOM VIEW)
(BOTTOM VIEW)
■PIN
ASSIGNMENT
SOT-25
1
2
3
4
5
PIN NUMBER
USP-6C/USP-6EL
6
2, 5
4
3
1
WLP-5-03
2
3
1
4
5
PIN NAME
V
IN
V
SS
CE / MODE
V
OUT
FB
Lx
FUNCTIONS
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
■FUNCTION
CE/MODE
OPERATIONAL STATES
XC9235
XC9236
Synchronous
PWM Fixed
Control
Stand-by
Synchronous
PWM/PFM
Automatic Switching
Stand-by
CE/MODE
OPERATIONAL STATES
XC9237
Synchronous
PWM/PFM
Automatic Switching
Synchronous PWM Fixed Control
Stand-by
H Level
(*1)
L Level
(*2)
H
Level
(*3)
M Level
(*4)
L Level
(*5)
CE/MODE pin voltage level range
(*1)
(*2)
(*3)
(*4)
(*5)
(*6)
H
Level
：
V
IN
0.65V
≦
H
Level
≦
6.0V
L
Level
：
0V
≦
L
Level
≦
0.25V
H
Level
：
V
IN
- 0.25V
≦
H
Level
≦
6.0V
M
Level
：
0.65V
≦
M
Level
≦
V
IN
- 1.0V
L
Level
：
0V
≦
L
Level
≦
0.25V
For XC9235 / XC9236 / XC9237B ~ G types, the internal resistance turns on during standby.
Please do not leave the CE/MODE pin open.
Discharge the CL charge through the CL discharge resistor.
(*7)
4/33
XC9235/XC9236/XC9237
Series
■ABSOLUTE
MAXIMUM RATINGS
PARAMETER
V
IN
Pin Voltage
Lx Pin Voltage
V
OUT
Pin Voltage
FB Pin Voltage
CE/MODE Pin Voltage
Lx Pin Current
SOT-25
Power
Dissipation
(Ta=25℃)
SYMBOL
V
IN
V
LX
V
OUT
V
FB
V
CE/MODE
I
Lx
RATINGS
- 0.3 ~ 6.5
- 0.3 ~ V
IN
+ 0.3
- 0.3 ~ 6.5
- 0.3 ~ 6.5
- 0.3 ~ 6.5
±1500
250
600 (40mm x 40mm Standard board)
(*1)
760 (JESD51-7 board)
(*1)
Pd
120
1000 (40mm x 40mm Standard board )
(*1)
1250 (JESD51-7 board
(*1)
120
1000 (40mm x 40mm Standard board )
(*1)
750 (40mm x 40mm Standard board )
(*1)
Topr
Tstg
- 40 ~ + 85
- 55 ~ + 125
O
UNIT
V
V
V
V
V
mA
USP-6C
mW
USP-6EL
WLP-5-03
Operating Ambient Temperature
Storage Temperature
(*1)
C
O
C
The power dissipation figure shown is PCB mounted and is for reference only.
Please refer to PACKAGING INFORMATION for the mounting condition.
5/33
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