SMALL PACKAGE PFM CONTROL STEP-UP DC/DC CONVERTER
RADIO COMPANY, LTD.
CE8301 Series
LESHAN
SMALL PACKAGE PFM CONTROL
STEP-UP DC/DC CONVERTER
LR8301 Series
Introduction
The LR8301 Series
is a CMOS PFM-control
step-up switching DC/DC converter that
mainly consists of a reference voltage
source, an oscillator, and a comparator. The
PFM controller allows the duty ratio to be
automatically switched according to the load
(light load: 50%, high output current: 75%),
enabling products with a low ripple over a
wide range, high efficiency, and high output
current. With the LR8301 Series, a step-up
switching
configured
DC/DC
by
converter
an
can
be
coil,
using
external
Features
• Low voltage operation: Startup at 0.9 V
min. (I
OUT
= 1 mA) guaranteed
• Duty ratio: 66/78%, builtin auto switching
type PFM controller
• External parts: Coil, capacitor, diode
• Output voltage: Settable to between 1.8
to 6.0 V in 0.1 V steps
• Accuracy of ±2%
• High efficiency：±85%（typ.）
• Standard function (product type A)
• Shutdown function (product type C、D)
• External transistor type available
(product type B、D)
capacitor, and diode. The built-in MOS FET is
turned off by a protection circuit when the
voltage at the LX pin exceeds the limit to
prevent it from being damaged. This feature,
along with the mini package and low current
consumption, makes the
LR8301
Series
ideal for applications such as the power
supply unit of portable equipment.
Applications
• Power supply for portable equipment such
as digital cameras, electronic notebooks, and
PDAs
• Power supply for audio equipment such as
portable CD/MD players
• Constant voltage power supply for cameras,
video equipment, and communications
equipment
• Power supply for microcomputers
V0.2
1(9)
Ordering Information
LR8301
LESHAN RADIO COMPANY, LTD.
Table 5
Pin No.
1
2
3
Pin Name
V
SS
V
OUT
LX
Table 6
Pin No.
1
2
3
Pin Name
V
SS
V
OUT
EXT
Table 7
Pin No.
1
2
3
4
5
Pin Name
NC
V
OUT
EN
LX
V
SS
Table 8
Pin No.
1
2
3
4
5
Pin Name
NC
V
OUT
EN
EXT
V
SS
LR8301A Series
（SOT-89-3
PKG）
Functions
GND pin
Output voltage pin
External inductor connection pin
LR8301B Series
（SOT-89-3
PKG）
Functions
GND pin
Output voltage pin
External transistor connection pin
LR8301C Series
（SOT-89-5
PKG）
Functions
(N.C.)
Output voltage pin
Shutdown pin
“H”: Normal operation
“L”: Step-up stopped
External inductor connection pin
GND pin
LR8301D Series
（SOT-89-5
PKG）
Functions
(N.C.)
Output voltage pin
Shutdown pin
“H”: Normal operation
“L”: Step-up stopped
External transistor connection pin
GND pin
Absolute Maximum Ratings
(Unless otherwise specified, Ta=25
C)
Parameter
V
OUT
pin voltage
EN
LX
LX
pin voltage
pin voltage
pin current
SOT-23-3
SOT-23-5
SOT-89-3
Symbol
V
OUT
EN
V
LX
I
LX
PD
Topr
Tstg
Ratings
V
SS
－0.3
~ V
SS
＋８
V
SS
－0.3
~ V
SS
＋８
V
SS
－0.3
~ V
SS
＋８
1000
250
250
500
－40
~＋85
－40
~＋125
Unit
V
V
V
mA
mW
mW
mW
°C
°C
Power
dissipation
Operating temperature
Storage temperature
V0.2
3(9)
LESHAN RADIO COMPANY, LTD.
Electrical Characteristics
(Unless otherwise specified, Ta =25
C)
Parameter
Output voltage
Input voltage
Operation start voltage
Oscillation start voltage
Symbol
V
OUT
V
IN
V
ST1
V
ST2
Conditions
－
－
I
OUT
= 1 mA
No external parts, voltage
applied to V
OUT
LX pulled up
to V
OUT
via 300Ω resistor
Min.
V
OUT(S)
×0.98
－
－
－
－
－
－
100
－
－
－
Typ.
V
OUT
－
－
－
30
50
6
－
200
－
20
20
100
Max.
V
OUT(S)
×1.02
6
0.9
0.8
40
60
10
0.5
－
0.5
50
50
Unit
V
V
V
V
µA
µA
µA
µA
mA
µA
mV
mV
kHz
Current consumption 1
Current consumption 2
Current consumption
during
shutdown
Switching current
Switching transistor
leakage current
Line regulation
Load regulation
Maximum Oscillation
frequency
Duty ratio 1
I
SS1
I
SS2
I
SSS
I
SW
I
SWQ
∆V
OUT1
∆V
OUT2
f
OSC
V
OUT
=0.95
×V
OUT
V
OUT
：
3.0V
5.0V
V
OUT
：
V
OUT
=V
OUT
＋0.5
V
V
EN
= 0 V
V
LX
= 0.4 V
No external parts,
V
LX
＝V
OUT
=10 V ,V
EN
= 0 V
V
IN
= 0.4×V
OUT
½
0.6×V
OUT
I
OUT
= 10 µA ~ 50mA
V
OUT
= 0.95×V
OUT
，
measure
waveform at LX pin
Duty1
V
OUT
= 0.95×V
OUT
，
measure waveform at
LX pin
Measure waveform at
LX pin with light load
V
OUT
=0.95×V
OUT
，
judge
oscillation at LX pin
V
OUT
= 0.95×V
OUT
，
judge stop at LX pin
V
EN
＝10V
V
EN
＝0V
70
78
85
%
Duty ratio 2
Efficiency
Shutdown pin input
voltage
Shutdown pin input
current
Duty2
EFFI
V
SH
V
SL1
I
SH
I
SL
－
66
85
－
%
%
0.75
－
－0.1
－0.1
－
－
－
－
－
0.3
0.1
0.1
V
V
µA
µA
Remark： V
IN
=V
OUT(S)
×
0.6 applied, I
OUT
=V
OUT(S)
/ 250
Ω
Shutdown function built-in type: EN pin is connected to V
OUT
V
OUT(S)
specified above is the set output voltage value, and V
OUT
is the typical value of the actual
output voltage.
V0.2
4(9)
LESHAN RADIO COMPANY, LTD.
■
Standard Circuits
Component:
Inductor：47uH(Sumida)
Capacitor：47uF/16V(Tantalume type)
NMOS：XP151、XP161
Base Capacitor(Cb)：2200pF
R
FB
：Set
up so that R
FB1
/
B2
=Vout-1(Vout=set-up output voltage),
Please use with R
FB1
+R
FB2
≤2M
Ω
C
FB
：Set
up that Fzfb=1/(2×π×C
FB
×R
FB1
) is within the Adjustments necessary
in respect of L,C
L
.
Diode：IN5817、IN5819
Transistor：2SD1628G、2SD3279
Base Resistor(Rb)：1K
Ω
1、 LR8301A Circuits：
2、LR8301C Circuits：
3、LR8301B Circuits：
4、LR8301D Circuits：
V0.2
5(9)
Microcontroller MCU
京公网安备 11010802033920号
EEWORLD
