ELM93series

ELM93xxxB CMOS High efficiency PFM step-up DC/DC converter
■General description
ELM93xxxB is CMOS step-up DC/DC converter which consists of reference voltage source, error amplifier,
oscillation circuit, start-up circuit, PFM control circuit, switching transistor and output voltage setting resistor.
For external parts, coil, diode and capacitor are possible choices; with external parts, ELM93 series is able to
acquire constant output voltage higher than input voltage. The standard output voltages are 2.7V, 3.0V, and 3.3V;
ELM93 series can also be designed as semi-custom IC within the range of 1.8V to 3.8V by 0.1V step.
■Features
•
•
•
•
•
•
•
■Application
Output voltage range
Low voltage operation
Low power operation
High efficiency
High output voltage accuracy
Output current (e.g.)
Package
: 1.8V to 3.8V (by 0.1V)
: Vin≥0.9V(RL=30kΩ)
: Typ.24μW(ELM9330xB)
: Typ.85%
: ±2.5%
: 40mA(Vin=1.5V, Vout=3.0V)
: SOT-89, SOT-23
• Constant voltage source for batteryoperated devices
• Constant voltage source for cameras
• Portable communications equipments
• Local regulator
■Maximum absolute ratings
Parameter
Apply voltage to LX pin
Apply voltage to VOUT pin
Output current of LX pin
Power dissipation
Symbol
Vlx
Vout
Ilx
Limit
5
4
200
500 (SOT-89)
250 (SOT-23)
-40 to +85
-55 to +125
Pd
Operating temperature
Storage temperature
Top
Tstg
Unit
V
V
mA
mW
°C
°C
■Selection guide
ELM93xxxB-x
Symbol
a, b
Output voltage
c
Package
d
Product version
e
Taping direction
e.g. :
27: Vout=2.7V
30: Vout=3.0V
33: Vout=3.3V
A: SOT-89
B: SOT-23
B
S: Refer to PKG file
N: Refer to PKG file
8-1
ELM93 x x x B - x
↑ ↑ ↑ ↑ ↑
a b c d e
ELM93xxxB CMOS High efficiency PFM step-up DC/DC converter
■Pin configuration
SOT-89(TOP VIEW)
SOT-23(TOP VIEW)
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Pin No.
1
2
3
�
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Pin name
VSS
VOUT
LX
�
Pin No.
1
2
3
Pin name
VSS
LX
VOUT
■Standard circuit
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Cin : The circuit can operate without Cin, but adding Cin to the circuit can lower the feedback noise to the Input; this method is also effective in improving efficiency because
input voltage drop during switching can be eased. Under the condition of Iout≤10mA,
please connect tantalum capacitor of 10μF to 47μF to a coil as close as possible.
■Block diagram
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8-2
ELM93xxxB CMOS High efficiency PFM step-up DC/DC converter
■Electrical characteristics
Vout=2.7V(ELM9327xB)
Parameter
Starting voltage
Holding voltage
Current consumption
Output voltage
Output current of LX pin
Leakage current of LX pin
Oscillating frequency
Duty ratio
Vout=3.0V(ELM9330xB)
Parameter
Starting voltage
Holding voltage
Current consumption
Output voltage
Output current of LX pin
Leakage current of LX pin
Oscillating frequency
Duty ratio
Vout=3.3V(ELM9333xB)
Parameter
Starting voltage
Holding voltage
Current consumption
Output voltage
Output current of LX pin
Leakage current of LX pin
Oscillating frequency
Duty ratio
L=330μH, Cin=Cout=22μF, D=MA721, Vss=0V, Top=25°C
Symbol
Condition
Min.
Typ.
Max.
Unit
Vst RL=30kΩ
0.9
V
Vhold Iout=1mA
0.7
V
Iss
Iout=100μA, Vin=1.5V
8.0
16.0
μA
Vout Iout=1mA, Vin=1.5V
2.63
2.70
2.77
V
Ilx
Vout=2.6V, Vlx=0.4V
60
mA
Ilxl Vout=3.5V, Vlx=3.5V
1.0
μA
Fosc Vout=2.6V
80
100
120
kHz
Duty Vout=2.6V, Switch"ON"
65
75
85
%
Symbol
Vst
Vhold
Iss
Vout
Ilx
Ilxl
Fosc
Duty
L=330μH, Cin=Cout=22μF, D=MA721, Vss=0V, Top=25°C
Condition
Min.
Typ.
Max.
Unit
RL=30kΩ
0.9
V
Iout=1mA
0.7
V
Iout=100μA, Vin=1.5V
8.0
16.0
μA
Iout=1mA, Vin=1.5V
2.92
3.00
3.08
V
Vout=2.9V, Vlx=0.4V
70
mA
Vout=3.5V, Vlx=3.5V
1.0
μA
Vout=2.9V
80
100
120
kHz
Vout=2.9V, Switch"ON"
65
75
85
%
Symbol
Vst
Vhold
Iss
Vout
Ilx
Ilxl
Fosc
Duty
L=330μH, Cin=Cout=22μF, D=MA721, Vss=0V, Top=25°C
Condition
Min.
Typ.
Max.
Unit
RL=30kΩ
0.9
V
Iout=1mA
0.7
V
Iout=100μA, Vin=1.5V
8.0
16.0
μA
Iout=1mA, Vin=1.5V
3.21
3.30
3.39
V
Vout=3.2V, Vlx=0.4V
80
mA
Vout=3.5V, Vlx=3.5V
1.0
μA
Vout=3.2V
80
100
120
kHz
Vout=3.2V, Switch"ON"
65
75
85
%
8-3
ELM93xxxB CMOS High efficiency PFM step-up DC/DC converter
■Marking
SOT-89
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� �
SOT-23
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a : the integer digit of the output voltage
Mark
Vout
1
1.*V
2
2.*V
3
3.*V
b : the decimal digit of the output voltage
Mark
Vout
0
*.0V
1
*.1V
2
*.2V
3
*.3V
4
*.4V
5
*.5V
6
*.6V
7
*.7V
8
*.8V
9
*.9V
c, d : Assembly lot No.
50 to 99
■External parts
To design DC/DC converters using ELM93 series, coil, diode, and capacitor are necessary.
(Refer to the standard circuit configuration.)
1) Coil
When choosing choke coil, please select that whose core is not magnetically saturated, DC resistance is
low, and which has sufficient margin for rated current.
For ELM93 series, ELM recommends following coil.
• CM-5/CM-5N (Sumida Electric Co., Ltd.)
2) Diode
When choosing diode, please select that whose forward voltage is small, switching speed is high and which
has sufficient margin for rated current.
For ELM93 series, ELM recommends schottoky diodes.
8-4
ELM93xxxB CMOS High efficiency PFM step-up DC/DC converter
3) Capacitor
When choosing capacitor, please select that which is generally used for smoothing power supply circuit,
with comparatively large capacity and whose rated voltage is at least three times larger than rated output
voltage of used ELM93 series.
For ELM93 series, ELM recommends Aluminum electrolytic or Tantalum capacitor.
Under different conditions, such as different input voltage, load current, etc. larger output voltage ripple
may happen and thus result in intermittent switching. To solve this, using capacitors with larger capacity
can prevent output voltage ripple from becoming larger.
Inserting resistor, as shown in the following circuit, may also be effective.
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■Design of DC/DC converter
In the DC/DC converter which consists of ELM93 series and above-mentioned external parts, the output is
acquired as follows:
1) Output current of DC/DC converter
The current from the output terminal (VOUT) of the circuit is:
9Vin 2
Iout = K
* Duty=75%
32 • L • Fosc • (Vout-Vin)
K: the efficiency of whole circuit (≈75% to ≈85%)
2) Remedies for noise
This DC/DC converter may cause electromagnetic noise due to switching of coil under large current. Solution is necessary especially when the IC is used in wireless devices.
To reduce noise, this IC is designed in consideration of the coil switching characteristics. The following
methods are also effective to reduce noise.
• Use shield-type, or magnetic shield coil.
• Locate coil and diode to the LX terminal of IC as close as possible.
• Select ground wire as thick and short as possible.
• Connect ground wire of circuit to one point.
8-5
ELM93xxxB CMOS High efficiency PFM step-up DC/DC converter
■Typical characteristics
• Vout=2.7V(ELM9327xB) (Top=25°C, L=330μH, D=MA721, Cin=Cout=22μF)
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
EFFICIENCY
(%)
EFFICIENCY
(%)
EFFICIENCY
(%)
EFFICIENCY
(%)
100
100
100
100
100
100
90
90
90
90
90
90
80
80
80
80
80
80
Iout=10mA
Iout=10mA
Iout=10mA
Iout=10mA
Iout=10mA
Iout=10mA
3mA
3mA
3mA
3mA
3mA
3mA
1mA
1mA
1mA
1mA
1mA
111mA
1
1
11Vin (V)
Vin (V)
Vin
(V)
Vin
Vin (V)
(V)
60
600
60
60
60
60000
00
Iout=1mA
Iout=1mA
Iout=1mA
Iout=1mA
Iout=1mA
Iout=1mA
100
100�
�A
A
100
��
A
100
A
100
100�
�A
A
100
100
100
100
100
100
11
1111Vin
Vin (V)
(V)
Vin
(V)
Vin
Vin (V)
(V)
22
2222
VOLTAGE
VOLTAGE RIPPLE
RIPPLE -- Vin
Vin
VOLTAGE
RIPPLE
Vin
VOLTAGE
VOLTAGE RIPPLE
RIPPLE --- Vin
Vin
80
80
80
80
80
80
60
60
60
60
60
60
40
40
40
40
40
40
Iout=1mA
Iout=1mA
Iout=1mA
Iout=1mA
Iout=1mA
Iout=1mA
20
20
20
20
20
20
00
0000
11
11
11 (V)
Vin
Vin
(V)
Vin
(V)
Vin
Vin (V)
(V)
Vin=0.9V
Vin=0.9V
Vin=0.9V
Vin=0.9V
Vin=0.9V
Vin=0.9V
22
2222
11
0.1
0.1
1110.1
10.1
0.1
0.1
22
2222
EFFICIENCY
EFFICIENCY -- Vin
Vin
EFFICIENCY
Vin
EFFICIENCY
EFFICIENCY --- Vin
Vin
70
70
70
70
70
70
1.8V
1.8V
1.8V
1.8V
1.8V
1.8V
1.5
1.5
1.5
1.5
1.5
1.5
EFFICIENCY
(%)
EFFICIENCY
(%)
EFFICIENCY
(%)
EFFICIENCY
(%)
11
0
1111000
00
Vout
(V)
Vout
(V)
Vout
(V)
Vout
(V)
33
3333
22
2222
Vout
Vout -- Iout
Iout
Vout
Iout
Vout
Vout --- Iout
Iout
3.5
3.5
3.5
3.5
3.5
3.5
33
3333
1.5
1.5
1.5
1.5
1.5
1.5
VOLTAGE
RIPPLE
(mV)
VOLTAGE
RIPPLE
(mV)
VOLTAGE
RIPPLE
(mV)
VOLTAGE
RIPPLE
(mV)
Vout
Vout -- Vin
Vin
Vout
Vin
Vout
Vout --- Vin
Vin
Iout(max.)
(mA)
Iout(max.)
(mA)
Iout(max.)
(mA)
Iout(max.)
(mA)
Vout
(V)
Vout
(V)
Vout
(V)
Vout
(V)
3.5
3.5
3.5
3.5
3.5
3.5
100
100
100
100
100
100
90
90
90
90
90
90
80
80
80
80
80
80
70
70
70
70
70
70
60
60
60
60
60
60
50
50
50
50
50
50
40
400.1
40
40
0.1
40
40
0.1
0.1
0.1
0.1
70
70
70
70
70
70
60
60
60
60
60
60
50
50
50
50
50
50
40
40
40
40
40
40
30
30
30
30
30
30
20
20
20
20
20
20
10
10
10
10
10
10
00
0000
22
2222
8-6
1
111
1.1V
1.1V
1.1V
1.1V
1.1V
1.1V
1.3V
1.3V
1.3V
1.3V
1.3V
1.3V
1.5V
1.5V
1.5V
1.5V
1.5V
1.5V
11
1111 Iout
10
10
10
10
100
100
100
100
100
100
10
Iout (mA)
(mA)10
Iout
(mA)
Iout
Iout (mA)
(mA)
EFFICIENCY
EFFICIENCY -- Iout
Iout
EFFICIENCY
Iout
EFFICIENCY
EFFICIENCY --- Iout
Iout
1.8V
1.8V
1.8V
1.8V
1.8V
1.8V
Vin=0.9V
Vin=0.9V
Vin=0.9V
Vin=0.9V
Vin=0.9V
Vin=0.9V
1.1V
1.1V
1.1V
1.1V
1.1V
1.1V
1.3V
1.3V
1.3V
1.3V
1.3V
1.3V
1.5V
1.5V
1.5V
1.5V
1.5V
1.5V
11
1111Iout
10
10
10
10
100
100
100
100
100
100
10
Iout (mA)
(mA)10
Iout
(mA)
Iout
Iout (mA)
(mA)
Iout(max.)
Iout(max.) -- L
L
Iout(max.)
L
Iout(max.)
Iout(max.) --- L
L
Vin=1.5V
Vin=1.5V
Vin=1.5V
Vin=1.5V
Vin=1.5V
Vin=1.5V
1.1V
1.1V
1.1V
1.1V
1.1V
1.1V
200
200
200
200
200
200
1.0V
1.0V
1.0V
1.0V
1.0V
1.0V
0.9V
0.9V
0.9V
0.9V
0.9V
0.9V
400
600
400
600
400
600
400
600
400
400
600
600
L (�H)
L (�H)
L
(�H)
L
L (�H)
(�H)
800
800
800
800
800
800
1000
1000
1000
1000
1000
1000
ELM93xxxB CMOS High efficiency PFM step-up DC/DC converter
• Vout=3.0V(ELM9330xB) (Top=25°C, L=330μH, D=MA721, Cin=Cout=22μF)
Vout - Vin
Vout
Vin
Vout
Vout --- Vin
Vin
3
3333
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
Iout=10mA
Iout=10mA
Iout=10mA
Iout=10mA
Iout=10mA
1.5
1.5
1.5
1.5
1.5
EFFICIENCY
(%)
EFFICIENCY
(%)
EFFICIENCY
(%)
EFFICIENCY
(%)
100
100
100
100
100
Vin (V)
Vin
(V)
Vin
Vin (V)
(V)
2
2222
100�A
100
��
A
100
A
100
100�
�A
A
70
70
70
70
70
100
100
100
100
100
1
1111
Vin (V)
Vin
(V)
Vin
Vin (V)
(V)
2
2222
80
80
80
80
80
Iout=1mA
Iout=1mA
Iout=1mA
Iout=1mA
Iout=1mA
40
40
40
40
40
20
20
20
20
20
0
0000
1
1111
2
22
Vin (V) 22
Vin
(V)
Vin
Vin (V)
(V)
8-7
2
222
100
100
100
100
100
EFFICIENCY - Iout
EFFICIENCY
Iout
EFFICIENCY
EFFICIENCY --- Iout
Iout
90
90
90
90
90
1.8V
1.8V
1.8V
1.8V
1.8V
80
80
80
80
80
Vin=0.9V
Vin=0.9V
Vin=0.9V
Vin=0.9V
Vin=0.9V
1.1V
1.1V
1.1V
1.1V
1.1V
70
70
70
70
70
60
60
60
60
60
1.3V
1.3V
1.3V
1.3V
1.3V
50
50
50
50
50
70
70
70
70
70
60
60
60
60
60
50
50
50
50
50
40
40
40
40
40
30
30
30
30
30
20
20
20
20
20
10
10
10
10
10
0
0000
3
3333
10
10
10
10
Iout (mA)10
Iout
(mA)
Iout
Iout (mA)
(mA)
40
0.1
40
40
40
40
0.1
0.1
0.1
0.1
3
3333
VOLTAGE RIPPLE - Vin
VOLTAGE
RIPPLE
Vin
VOLTAGE
VOLTAGE RIPPLE
RIPPLE --- Vin
Vin
60
60
60
60
60
1
1111 Iout
100
100
100
100
100
Iout=1mA
Iout=1mA
Iout=1mA
Iout=1mA
Iout=1mA
80
80
80
80
80
1.3V
1.3V
1.3V
1.3V
1.3V
1.5V
1.5V
1.5V
1.5V
1.5V
2
2222
1
0.1
1110.1
10.1
0.1
0.1
3
3333
EFFICIENCY - Vin
EFFICIENCY
Vin
EFFICIENCY
EFFICIENCY --- Vin
Vin
90
90
90
90
90
60
0
60
60
60
6000
00
VOLTAGE
RIPPLE
(mV)
VOLTAGE
RIPPLE
(mV)
VOLTAGE
RIPPLE
(mV)
VOLTAGE
RIPPLE
(mV)
1
1111
1.8V
1.8V
1.8V
1.8V
1.8V
1.1V
1.1V
1.1V
1.1V
Vin=0.9V 1.1V
Vin=0.9V
Vin=0.9V
Vin=0.9V
Vin=0.9V
1.5
1.5
1.5
1.5
1.5
3mA
3mA
3mA
3mA
3mA
1mA
1mA
1mA
1mA
1mA
EFFICIENCY
(%)
EFFICIENCY
(%)
EFFICIENCY
(%)
EFFICIENCY
(%)
1
0
111100
00
Vout
(V)
Vout
(V)
Vout
(V)
Vout
(V)
3
3333
2
2222
Vout - Iout
Vout
Iout
Vout
Vout --- Iout
Iout
3.5
3.5
3.5
3.5
3.5
Iout(max.)
(mA)
Iout(max.)
(mA)
Iout(max.)
(mA)
Iout(max.)
(mA)
Vout
(V)
Vout
(V)
Vout
(V)
Vout
(V)
3.5
3.5
3.5
3.5
3.5
1
1111 Iout
10
10
10
1.5V
1.5V
1.5V
1.5V
1.5V
100
100
100
100
100
10
Iout (mA)10
Iout
(mA)
Iout
Iout (mA)
(mA)
Iout(max.) - L
Iout(max.)
L
Iout(max.)
Iout(max.) --- L
L
Vin=1.5V
Vin=1.5V
Vin=1.5V
Vin=1.5V
Vin=1.5V
1.1V
1.1V
1.1V
1.1V
1.1V
200
200
200
200
200
1.0V
1.0V
1.0V
1.0V
1.0V
400
400
400
400
400
L
0.9V
0.9V
0.9V
0.9V
0.9V
600
600
600
600
600
L (�H)
L
(�H)
LL (�H)
(�H)
800
800
800
800
800
1000
1000
1000
1000
1000
ELM93xxxB CMOS High efficiency PFM step-up DC/DC converter
• Vout=3.3V(ELM9333xB) (Top=25°C, L=330μH, D=MA721, Cin=Cout=22μF)
3mA
3mA
3mA
3mA
3mA
3mA
22
2222
1mA
1mA
1mA
1mA
1mA
1mA
1.5
1.5
1.5
1.5
1.5
1.5
11
0
1111000
00
EFFICIENCY
(%)
EFFICIENCY
(%)
EFFICIENCY
(%)
EFFICIENCY
(%)
100
100
100
100
100
100
11
1111
Vin
Vin (V)
(V)
Vin
(V)
Vin
Vin (V)
(V)
22
2222
11
0.1
0.1
1110.1
10.1
0.1
0.1
33
3333
100
100
100
100
100
100
90
90
90
90
90
90
80
80
80
80
80
80
70
70
70
70
70
70
60
60
60
60
60
60
50
50
50
50
50
50
40
400.1
40
40
0.1
40
40
0.1
0.1
0.1
0.1
100
100�
�A
A
100
��
A
100
A
100
100�
�A
A
70
70
70
70
70
70
100
100
100
100
100
100
11
1111
22
22
Vin
Vin (V)
(V) 22
Vin
(V)
Vin
Vin (V)
(V)
VOLTAGE
VOLTAGE RIPPLE
RIPPLE -- Vin
Vin
VOLTAGE
RIPPLE
Vin
VOLTAGE
VOLTAGE RIPPLE
RIPPLE --- Vin
Vin
80
80
80
80
80
80
60
60
60
60
60
60
Iout=1mA
Iout=1mA
Iout=1mA
Iout=1mA
Iout=1mA
Iout=1mA
40
40
40
40
40
40
20
20
20
20
20
20
00
0000
11
1111
22
22
Vin
Vin (V)
(V) 22
Vin
(V)
Vin
Vin (V)
(V)
70
70
70
70
70
70
60
60
60
60
60
60
50
50
50
50
50
50
40
40
40
40
40
40
30
30
30
30
30
30
20
20
20
20
20
20
10
10
10
10
10
10
00
0000
33
3333
8-8
3
333
1.1V
1.1V
1.1V
1.1V
1.1V
1.1V
1.3V
1.3V
1.3V
1.3V
1.3V
1.3V
1.5V
1.5V
1.5V
1.5V
1.5V
1.5V
22
2222
33
3333
Iout=1mA
Iout=1mA
Iout=1mA
Iout=1mA
Iout=1mA
Iout=1mA
80
80
80
80
80
80
Vin=0.9V
Vin=0.9V
Vin=0.9V
Vin=0.9V
Vin=0.9V
Vin=0.9V
2.5
2.5
2.5
2.5
2.5
2.5
1.5
1.5
1.5
1.5
1.5
1.5
EFFICIENCY
EFFICIENCY -- Vin
Vin
EFFICIENCY
Vin
EFFICIENCY
EFFICIENCY --- Vin
Vin
90
90
90
90
90
90
60
600
60
60
60
60000
00
VOLTAGE
RIPPLE
(mV)
VOLTAGE
RIPPLE
(mV)
VOLTAGE
RIPPLE
(mV)
VOLTAGE
RIPPLE
(mV)
33
3333
Iout=10mA
Iout=10mA
Iout=10mA
Iout=10mA
Iout=10mA
Iout=10mA
Vout
(V)
Vout
(V)
Vout
(V)
Vout
(V)
2.5
2.5
2.5
2.5
2.5
2.5
Vout
Vout -- Iout
Iout
Vout
Iout
Vout
Vout --- Iout
Iout
3.5
3.5
3.5
3.5
3.5
3.5
Iout(max.)
(mA)
Iout(max.)
(mA)
Iout(max.)
(mA)
Iout(max.)
(mA)
Vout
(V)
Vout
(V)
Vout
(V)
Vout
(V)
33
3333
Vout
Vout -- Vin
Vin
Vout
Vin
Vout
Vout --- Vin
Vin
EFFICIENCY
(%)
EFFICIENCY
(%)
EFFICIENCY
(%)
EFFICIENCY
(%)
3.5
3.5
3.5
3.5
3.5
3.5
11
1111 Iout
1.8V
1.8V
1.8V
1.8V
1.8V
1.8V
10
10
10
10
100
100
100
100
100
100
10
Iout (mA)
(mA)10
Iout
(mA)
Iout
Iout (mA)
(mA)
EFFICIENCY
EFFICIENCY -- Iout
Iout
EFFICIENCY
Iout
EFFICIENCY
EFFICIENCY --- Iout
Iout
Vin=0.9V
Vin=0.9V
Vin=0.9V
Vin=0.9V
Vin=0.9V
Vin=0.9V
1.8V
1.8V
1.8V
1.8V
1.8V
1.8V
1.1V
1.1V
1.1V
1.1V
1.1V
1.1V
1.5V
1.5V
1.5V
1.5V
1.5V
1.5V
1.3V
1.3V
1.3V
1.3V
1.3V
1.3V
11
1111 Iout
10
10
10
10
100
100
100
100
100
100
10
Iout (mA)
(mA)10
Iout
(mA)
Iout
Iout (mA)
(mA)
Iout(max.)
Iout(max.) -- L
L
Iout(max.)
L
Iout(max.)
Iout(max.) --- L
L
Vin=1.5V
Vin=1.5V
Vin=1.5V
Vin=1.5V
Vin=1.5V
Vin=1.5V
1.1V
1.1V
1.1V
1.1V
1.1V
1.1V
200
200
200
200
200
200
1.0V
1.0V
1.0V
1.0V
1.0V
1.0V
0.9V
0.9V
0.9V
0.9V
0.9V
0.9V
400
600
400
600
400
600
400
600
400
400
600
L (�H)600
L (�H)
L
(�H)
L
L (�H)
(�H)
800
800
800
800
800
800
1000
1000
1000
1000
1000
1000