DC/DC Step up Converter ME2108 Series
Ver 07
DC/DC Step up Converter ME2108 Series
General Description：
ME2108 Series
is a PFM Step-up DC/DC
converter IC with low supply current by CMOS
process. High frequency noise that occurs during
switching is reduced by using advanced circuit
designed, output voltage is programmable in 0.1V
steps between 2.0~7.0V and maximum frequency is
180KHz(Typ.). A low ripple, high efficiency
step-up DC/DC converter can be constructed of
ME2108Xxx with only three external components.
Also available is a CE(chip enable) function that
reduce
power dissipation
During shut-down
mode. ME2108Xxx is suitable for use with
battery-powered instruments with low noise and
low supply current.
Features：
Low ripple and low noise
Operating voltage range：0.9V~6.5V
Output voltage range：2.0V~7.0V(step 0.1V)
Output voltage accuracy：±2.5%
Output Current：if Vin=3.0V and Vout=5.0V，
then Iout=400mA
Low start voltage：≤0.9V(at Iout=1mA)；
Maximum oscillator frequency：180KHz(Typ.)
High Efficiency：85%(Type)
PACKAGE：SOT23，SOT89
Selection Guide：
Applications：
Power source for battery-powered equipment
Power source for wireless mouse, wireless
keyboard, toys, cameras, camcorders, VCRs,
PDAs, and hand-held communication equipment
Power source for appliances which require
higher cell voltage than that of batteries used in
the appliances
Nanjing Micro One Electronics Inc.
1/12
TEL: 025-84731186
www. microne. com. cn
DC/DC Step up Converter ME2108 Series
Ver 07
TYPE
ME2108Axx
ME2108Bxx
ME2108Cxx
ME2108Dxx
ME2108Dxx
POSTFIX
M3
P
M3
P
M5
P
M5
P
M5
PACKAGE
SOT23-3
SOT89-3
SOT23-3
SOT89-3
SOT23-5
SOT89-5
SOT23-5
SOT89-5
SOT23-5
SWITCHING
TRANSISTOR
Build in
Transistor
External
Transistor
Build in
Transistor
External
Transistor
External
Transistor
CE
FUNCTION
No
No
Yes
Yes
Yes
FEATURES
Lx
Ext
Lx CE
Ext CE
Ext
Pin Configuration：
Pin Assignment：
ME2108Axx
PIN Number
SOT23-3
SOT89-3
1
1
3
2
2
3
ME2108Bxx
PIN Number
SOT23-3
SOT89-3
1
1
3
2
2
3
ME2108Cxx
PIN Number
SOT23-5
SOT89-5
4
5
2
2
5
4
1
3
3
1
PIN
NAME
Vss
Vout
Lx
PIN
NAME
Vss
Vout
Ext
PIN
NAME
Vss
Vout
Lx
CE
NC
FUNCTION
Ground
Output voltage monitor, IC internal power supply
Switch
FUNCTION
Ground
Output voltage monitor, IC internal power supply
External switch transistor drive
FUNCTION
Ground
Output voltage monitor, IC internal power supply
Switch
Chip enable
NC
Nanjing Micro One Electronics Inc.
2/12
TEL: 025-84731186
www. microne. com. cn
DC/DC Step up Converter ME2108 Series
Ver 07
ME2108Dxx
PIN Number
SOT23-5
SOT89-5
4
5
2
2
5
4
1
3
3
1
ME2108Fxx
PIN Number
SOT23-5
1
2
3
4
5
PIN NAME
Vss
Vout
Ext
CE
NC
PIN NAME
FB
Vdd
NC
Vss
EXT
FUNCTION
Ground
Output voltage monitor, IC internal power supply
External switch transistor drive
Chip enable
NC
FUNCTION
Feed Back
Output voltage monitor, IC internal power supply
NC
Ground
External switch transistor drive
Block Diagram：
Absolute Maximum Ratings：
PARAMETER
V
IN
Input Voltage
Lx Pin voltage
EXT Pin voltage
CE Pin voltage
Lx Pin current
EXT Pin current
Vdd input voltage
Continuous Total
SOT23
Power Dissipation
SOT89
Operating Ambient Temperature
Storage Temperature
Soldering temperature and time
SYMBAL
V
IN
V
LX
V
EXT
V
CE
I
LX
I
EXT
V
dd
Pd
Pd
T
Opr
T
stg
T
solder
RATINGS
6.5
6.5
-0.3~Vout+0.3
-0.3~Vout+0.3
600
±30
6.5
300
500
-25~+85
-40~+125
260℃, 10s
UNITS
V
V
V
V
mA
mA
V
mW
mW
℃
℃
Nanjing Micro One Electronics Inc.
3/12
TEL: 025-84731186
www. microne. com. cn
DC/DC Step up Converter ME2108 Series
Ver 07
Electrical Characteristics：
Measuring conditions：Unless otherwise specified , V
IN
=Vout*0.6，V
SS
=0V，I
OUT
=10mA，T
opt
=25℃。
ME2108Axx/Cxx
Fosc=180kHz
SYMBOL
V
OUT
V
start
V
hold
I
DD1
I
DD2
I
LX
I
LXleak
F
osc
Maxdty
EFFI
ME2108Bxx/Dxx
SYMBOL
V
OUT
V
start
V
hold
I
DD1
I
DD2
I
LX
I
LXleak
F
osc
Maxdty
EFFI
PARAMETER
Output Voltage
Oscillation
Start-up Voltage
Oscillation Hold
Voltage
Supply Current
1
Supply Current
2
Lx Switching
Current
Lx Leakage
Current
Oscillation
Frequency
Duty Ratio
Efficiency
Fosc=180kHz
CONDITIONS
I
OUT
=1mA，
V
IN
：0→2V
I
OUT
=1mA，
V
IN
：2→0V
No external component
Vout=Vout*0.95,
Vout=Vout+0.5V
V
LX
=0.4V,
Vout=Vout*0.95
Vout=V
LX
=6V
Vout=set Vout*0.95
on(V
LX
“L”)side
180
84
85
MIN
Vout*0.975
TYP
Vout
0.8
0.45
80
12
360
0.5
MAX
Vout*1.025
0.9
UNITS
V
V
V
µA
µA
mA
µA
kHz
%
%
I
OUT
=1mA，
V
IN
：0→2V
I
OUT
=1mA，
V
IN
：2→0V
No external
component
Vout=Vout*0.95,
Vout=Vout+0.5V
V
LX
=0.4V,
Vout=Vout*0.95
Vout=V
LX
=6V
Vout=set
Vout*0.95
on(V
LX
“L”)side
180
84
85
CONDITIONS
MIN
Vout*0.975
TYP
Vout
0.8
0.45
50
9
360
0.5
MAX
Vout*1.025
0.9
UNITS
V
V
V
µA
µA
mA
µA
kHz
%
%
PARAMETER
Output Voltage
Oscillation
Start-up Voltage
Oscillation Hold
Voltage
Supply Current
1
Supply Current
2
Lx Switching
Current
Lx Leakage
Current
Oscillation
Frequency
Duty Ratio
Efficiency
Nanjing Micro One Electronics Inc.
4/12
TEL: 025-84731186
www. microne. com. cn
DC/DC Step up Converter ME2108 Series
Ver 07
ME2108F
SYMBOL
V
FB
V
start
V
hold
I
DD1
I
DD2
I
LX
I
LXleak
F
osc
Maxdty
VFB=3.3V , Fosc=180kHz
PARAMETER
Output
Feedback
Voltage
Oscillation
Start-up Voltage
Oscillation Hold
Voltage
Supply Current
1
Supply Current
2
Lx Switching
Current
Lx Leakage
Current
Oscillation
Frequency
Duty Ratio
CONDITIONS
MIN
3.22
I
OUT
=1mA，
V
IN
：0→2V
I
OUT
=1mA，
V
IN
：2→0V
No external component
Vout=Vout*0.95,
Vout=Vout+0.5V
V
LX
=0.4V,
Vout=Vout*0.95
Vout=V
LX
=6V
Vout=set Vout*0.95
on(V
LX
“L”)side
180
84
85
IN5819 (forward voltage drop:0.2V)
TYP
3.3
0.8
0.45
80
10
360
0.5
MAX
3.38
0.9
UNITS
V
V
V
µA
µA
mA
µA
kHz
%
%
EFFI
Efficiency
Note：1、Diode use Schottky diode such as IN5817 or
2、Inductor：33μH（r<0.5Ω）
3、Capacitor：Tantalum type 100μF
Operation：
ME2108 step-up DC/DC converter charges energy in the inductor when Lx Transistor is on, and
discharges the energy with the addition of the energy from input power source thereto, so that a higher
output voltage than the input voltage is obtained. Following is the operation diagram.
Switching DC/DC Step up Converter operating process
Nanjing Micro One Electronics Inc.
5/12
TEL: 025-84731186
www. microne. com. cn
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