XC6371/XC6372
Series
PWM Controlled Step-Up DC/DC Converters
ETR0402_002
☆GreenOperation-Compatible
■GENERAL
DESCRIPTION
The XC6371/XC6372 series is a group of PWM controlled and PWM/PFM controlled step-up DC/DC converters. The built-in
1.4Ω switching transistor type enables a step-up circuit to be configured using only three components, a coil, a diode, and a
capacitor.
Output voltage can be selectable in the range from 2.0V to 7.0V in increments of 0.01V (accuracy:±2.5%). Oscillation
frequency is also selectable from 50kHz, 100kHz, and 180kHz (accuracy:±15%) for the XC6371 and the XC6372 series.
Soft-start time is internally set and offers protection against in-rush currents when the power is switched on and prevents
voltage overshoot. Packages with CE (chip enable) pin are also available which can reduce the IC power consumption
during during stand-by mode.
The XC6371 series is the standard PWM controlled products. The control of the XC6372 series switches from PWM to PFM
control during light loads when automatically switching is selected and the series is highly efficient from light loads to large
output currents.
■APPLICATIONS
●Cellular
phones, Pagers
●Palmtops
●Cameras,
Video recorders
●Portable
products
■FEATURES
Operation Start Voltage Range
: 0.9V~10V
Output Voltage Range
: 2.0V~7.0V (0.1V increments)
Highly Accurate
:
±2.5%
Oscillation Frequency
: 50kHz, 100kHz, 180kHz (±15%)
Maximum Output Currents
: 100mA(TYP.) @ V
IN
=3.0V, V
OUT
=5.0V *
Highly Efficient
: 85%(TYP.) @ V
IN
=3.0V, V
OUT
=5.0V *
Built-in switching transistor.
CE pin type (XC6371C, XC6372C)
Phase compensation and soft start-up circuits built-in
CMOS Low Power Consumption
Packages
: SOT-89, SOT-89-5, USP-6B
* Performance depends on external components and PCB layout.
■TYPICAL
APPLICATION CIRCUIT
■TYPICAL
PERFORMANCE
CHARACTERISTICS
1/17
XC6371/XC6372
Series
■PIN
CONFIGURATION
■PIN
ASSIGNMENT
XC6371/XC6372A
PIN NUMBER
SOT-89
1
2
3
−
USP-6B
6
1
4
2, 3, 5
PIN NAME
V
SS
V
OUT
Lx
NC
*The dissipation pad for the USP-6B
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 pin No.1.
FUNCTION
Ground
Output Voltage Monitor/IC Internal Power Supply
Switch
No Connection
XC6371/XC6372C
PIN NUMBER
SOT-89-5
5
2
4
3
1
USP-6B
6
1
4
3
2, 5
PIN NAME
V
SS
V
OUT
Lx
CE
NC
FUNCTION
Ground
Output Voltage Monitor/IC Internal Power Supply
Switch
Chip Enable
No Connection
2/17
XC6371/XC6372
Series
■PRODUCT
CLASSIFICATION
●Selection
Guide
START
PWM
XC6371
Standard
Chip Enable
XC6371A
XC6371C
PWM/PFM XC6372
Standard
Chip Enable
XC6372A
XC6372C
●Ordering
Information
XC6371①②③④⑤⑥ : PWM controlled
XC6372①②③④⑤⑥ : PWM/PFM switching control
DESIGNATOR
①
② ③
DESCRIPTION
Type of
DC/DC Converter
Output Voltage
SYMBOL
A
C
Integer
0
1
2
PR
DR
DESCRIPTION
3-pin DC/DC converter with built-in switching transistor
Stand-by capability with built-in switching transistor
e.g. V
OUT
=3.5V→②=3,
50kHz
100kHz
180kHz
SOT-89 (XC6371/72 A type)
SOT-89-5 (XC6371/72 C type)
USP-6B
③=5
XC6371 Series
④
Oscillation Frequency
⑤⑥
(*1)
Packages
Taping Type
(*1)
The device orientation is fixed in its embossed tape pocket.
For reverse orientation, please contact your local Torex sales office or representative.
(Standard orientation:
⑤R,
Reverse orientation:
⑤L)
3/17
XC6371/XC6372
Series
■BLOCK
DIAGRAMS
XC6371/XC6372A, C
(The V
OUT
pin serves also as V
DD
)
(
p
)
Soft Start
Vref
V
DD
V
OUT
Phase comp
Lx
VLx l imi ter
Buffer
PWM Control
OSC 50/100/180KHz
V
SS
EXT
Chip Enable
CE
+
−
Note: The CE pin is only used with the XC6371C.
XC6371/72/73E
V
DD
V
DD
Lx
VLx l imi ter
Buffer
PWM Control
OSC 50/100/180KHz
Soft Start
Vref
Phase comp
V
OUT
V
SS
EXT
+
−
Note: Built-in transistor type units use the Lx pin.
■ABSOLUTE
MAXIMUM RATINGS
Ta=25℃
PARAMETER
V
OUT
Input Voltage
L
X
pin Voltage
L
X
pin Current
CE Input Voltage
SOT-89,
SOT-89-5
Power Dissipation
USP-6B
V
DD
Input Voltage
Operating Temperature Range
Storage Temperature Range
SYMBOL
V
OUT
V
LX
I
LX
V
CE
P
d
V
DD
Topr
Tstg
RATINGS
12
12
400
12
500
100
12
-30~＋80
-40~＋125
UNITS
V
V
mA
V
mW
V
℃
℃
4/17
XC6371/XC6372
Series
■ELECTRICAL
CHARACTERISTICS
V
OUT
=5.0V, FOSC=100kHZ
XC6371/72A501
PARAMETER
SYMBOL
CONDITIONS
Output Voltage
V
OUT
Maximum Input Voltage
V
IN
Operation Start Voltage
V
ST1
External Components Connected, I
OUT
=1mA
No external components. Apply voltage to V
OUT
Oscillation Start Voltage
V
ST2
Lx : 10kΩ pull-up to 5V
(*1)
No Load Input Current
I
IN
V
IN
=V
OUT
×0.8,
I
OUT
=0mA
Same as V
ST2
,
Supply Current 1
I
DD1
Apply output voltage×0.95 to V
OUT
Same as V
ST2
,
Supply Current 2
I
DD2
Apply output voltage×1.1 to V
OUT
Lx Switch-On
R
SWON
Same as I
DD1
, V
LX
=0.4V
Resistance
Lx Leak Current
I
LXL
No external components. V
OUT
=V
LX
=10V
Oscillation Frequency
FOSC
Same as I
DD1
. Measuring of Lx waveform
Maximum Duty Ratio
MAXDTY
Same as I
DD1
. Measuring of Lx waveform
(*4)
PFM Duty Ratio
PFMDTY
Same as I
DD1
. Measuring of Lx waveform
Same as I
DD1
. Apply output voltage to Lx,
Lx Limit Voltage
V
LXLMT
Voltage required to produce FOSC×2
Efficiency
EFFI
Slow-Start Time
T
SS
MIN.
4.875
10
-
-
-
-
-
-
-
85
80
10
0.7
-
4.0
TYP.
5.000
-
-
-
12.8
80.2
8.2
1.4
-
100
87
17
-
85
10.0
Ta=25℃
MAX. UNITS
5.125
V
-
V
0.90
V
0.80
25.7
133.8
16.5
2.4
1.0
115
92
25
1.3
-
20.0
V
μA
μA
μA
Ω
μA
kHz
%
%
V
%
ms
NOTE: Unless otherwise stated, V
IN
=V
OUT
×0.6,
I
OUT
=50mA. See Typical Application Circuits, Circuit1
*1: The Schottky diode (SD) must be type MA735, with reverse current (I
R
)<1.0μA at reverse voltage (V
R
)=10.0V.(XC6372A)
*2: "Supply Current 1" is the supply current while the oscillator is continuously oscillating. In actual operation the oscillator periodically
operates which results in less average power consumption. The current actually provided by an external V
IN
source is represented by
"No Load Input Current (I
IN
)".
*3: When PWM operates at PWM Mode.
*4: When PFM operates at PFM Mode.(XC6372A)
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