XC9235/XC9236/XC9237
Series
600mA Driver Tr. Built-In, Synchronous Step-Down DC/DC Converters
ETR0514-015
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 (A½C types), 1.8V to 6.0V (D½G 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 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)
■TYPICAL
PERFORMANCE CHARACTERISTICS
●XC9235/XC9236/XC9237
D/F types (Output Voltage Externally Set)
Efficiency: EFFI (%)
Efficency:EFFI(%)
●Efficiency
vs. Output Current（f
OSC
=1.2MHz, V
OUT
=1.8V）
100
90
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
PWM/PFM Automatic Sw itching Control
1/40
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.
3/40
XC9235/XC9236/XC9237
Series
■BLOCK
DIAGRAM
●XC9235
/ XC9236 / XC9237 A Series
●XC9235
/ XC9236 / XC9237 B/C/E/G
●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
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
USP-6C
USP-6EL
WLP-5-03
Operating Ambient Temperature
Storage Temperature
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
120
120
750
- 40 ~ + 85
- 55 ~ + 125
Ta=25℃
UNIT
V
V
V
V
V
mA
Pd
mW
Topr
Tstg
C
O
C
O
5/40
PCB Design
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