AIC1620/AIC1621/AIC1622
High Efficiency Synchronous Step-Up DC/DC
Converter
Analog Integrations Corporation 4F, 9 Industry E. 9th Rd, Science-Based Industrial Park, Hsinchu, Taiwan
DS-1620-00 032502
TEL: 886-3-5772500
FAX: 886-3-5772510
www.analog.com.tw
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FEATURES
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High Efficiency 93% (V
IN
=2.4V, V
OUT
=3.3V,
I
OUT
=200mA).
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20
µ
A Quiescent Supply Current.
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Power-Saving Shutdown Mode (0.1
µ
A typical).
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Internal Synchronous Rectifier ( no external
diode )
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Selectable Current Limit for Reduced Ripple
( AIC1622 ).
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Low Noise , Anti-Ringing Feature ( AIC1622 )
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On-Chip Low Battery Detector.
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Low Battery Hysteresis
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APPLICATIONS
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Palmtop & Notebook Computers.
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PDAs
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Wireless Phones
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Pocket Organizers.
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Cameras.
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1 to 2-Cell Hand-Held Devices
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DESCRIPTION
The AIC1620/AIC1621/AIC1622 are high effi-
ciency step up DC-DC converter. The start-up
voltage is as low as 0.8V and operate with an
input voltage down to 0.7V. Consuming only
20
µ
A of quiescent current. These devices offer
a built-in synchronous rectifier that reduces
size and cost by eliminating the need for an ex-
ternal Schottky diode and improves overall effi-
ciency by minimizing losses.
The switching frequency depends on the load
and the input voltage can range up to 500KHz.
The peak current of the internal switch is fixed
at 0.8A (AIC1620), at 0.45A (AIC1621), or is
selectable (AIC1622) for design flexibility. Rip-
ple does not exceed the product of the switch
current limit and the filter capacitor equivalent
series resistance (ESR). The AIC1622 also fea-
tures a circuit that eliminates noise due to in-
ductor ringing.
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TYPICAL APPLICATION CIRCUIT
Output 3.3V, or
Adj. (1.8V to 4.0V)
up to 300mA
Low-Battery
Detect Out
FB
GND
+
ON
OFF
+
Low-Battery
Detect In
0.1
µ
F
V
IN
22
µ
H
220
µ
F
100
µ
F
AIC1620
AIC1621
AIC1622
OUT
REF
LBO
SHDN
LX
LBI
LBO
FB
AIC1620/AIC1621/AIC1622
2
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ORDERING INFORMATION
AIC1620CX XX
AIC1621C X XX
AIC1622C X XX
PIN CONFIGURATION
(MSOP8)
TOP VIEW
AIC1622
1
3
4
2
10
8
7
9
FB
LBI
LBO
CLSEL
REF
OUT
LX
GND
BATT
SHDN
5
6
(MSOP10)
TOP VIEW
GND
1
3
4
2
8
6
5
7
OUT
LBI
LBO
R E F
LX
SHDN
FB
AIC1620
AIC1621
Example: AIC1620COTR
à
In MSO8 Package & Taping &
Reel Packing Type
PACKING TYPE
TR: TAPE & REEL
PACKAGING TYPE
O: MSOP8 (for AIC1620/1)
O: MSOP10 (for AIC1622)
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ABSOLUTE MAXIMUM RATINGS
Supply Voltage (OUT to GND) 8.0V
Switch Voltage (LX to GND) V
OUT
+ 0.3V
Battery Voltage (Batt to GND) 6.0V
, LBO to GND 6.0V
LBI, REF, FB, CLSEL to GND V
OUT
+0.3V
Switch Current (LX) -1.5A to +1.5A
Output Current (OUT) -1.5A to +1.5A
Operating Temperature Range -40
°
C ~ +85
°
C
Storage Temperature Range -65
°
C ~150
°
C
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TEST CIRCUIT
Refer to Typical Application Circuit.
SHDN
AIC1620/AIC1621/AIC1622
3
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ELECTRICAL CHARACTERISTICS
(V
BATT
=2.0V, V
OUT
=3.3V (FB=V
OUT
), R
L
=
,
T
A
=25
°
C, unless otherwise specified.)
PARAMETER
TEST CONDITIONS
MIN.
TYP.
MAX.
UNIT
Minimum Input Voltage
0.7
V
Operating Voltage
1.1
4.0
V
Start-Up Voltage
R
L
=3K
(Note1)
0.8
1.1
V
Start-Up Voltage Tempco
-2
mV/
°
C
Output Voltage Range
1.8
4.0
Output Voltage
FB = V
OUT
3.17
3.3
3.43
V
AIC1620
AIC1622 (CLSEL=OUT)
300
400
Steady State Output Current
(Note 2)
FB=OUT
(
V
OUT
=3.3V) AIC1621
AIC1622 (CLSEL=GND)
150
220
mA
Reference Voltage
I
REF
= 0
1.199
1.23
1.261
V
Reference Voltage Tempco
0.024
mV/
°
C
Reference Load Regulation
I
REF
= 0 to 100
µ
A
10
30
mV
Reference Line Regulation
V
OUT
= 1.8V to 4V
5
10
mV/V
FB , LBI Input Threshold
1.199
1.23
1.261
V
Internal switch On-Resistance
I
LX
= 100mA
0.3
AIC1620,AIC1622(CLSEL = OUT)
0.6
0.8
1.0
LX Switch Current Limit
AIC1621,AIC1622(CLSEL = GND)
0.3
0.45
0.6
A
LX Leakage Current
V
LX
=0V, 4V; V
OUT
=4V
0.05
1
µ
A
Operating Current into OUT
(Note 3)
V
FB
= 1.4V , V
OUT
= 3.3V
20
35
µ
A
Shutdown Current into OUT
SHDN = GND
0.1
1
µ
A
V
OUT
= 3.3V ,I
LOAD
= 200mA
90
Efficiency
V
OUT
= 2V ,I
LOAD
= 1mA
85
%
LX Switch On-Time
V
FB
=1V , V
OUT
= 3.3V
2
4
7
µ
S
LX Switch Off-Time
V
FB
=1V , V
OUT
= 3.3V
0.6
0.9
1.3
µ
S
FB Input Current
V
FB
= 1.4V
0.03
50
nA
AIC1620/AIC1621/AIC1622
4
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ELECTRICAL CHARACTERISTICS
(Continued)
PARAMETER
TEST CONDITIONS
MIN.
TYP.
MAX.
UNIT
LBI Input Current
V
LBI
= 1.4V
1
50
nA
CLSEL Input Current
AIC1622 , CLSEL = OUT
1.4
3
µ
A
SHDN Input Current
V
SHDN
= 0 or V
OUT
0.07
50
nA
LBO Low Output Voltage
V
LBI
= 0, I
SINK
= 1mA
0.2
0.4
µ
A
LBO Off Leakage Current
V
LBO
= 5.5V, V
LBI
= 5.5V
0.07
1
LBI Hystereisis
50
mV
Damping Switch Resistance
AIC1622, V
BATT
= 2V
50
100
0.2V
OUT
SHDN Input Voltage
0.8V
OUT
V
0.2V
OUT
CLSEL Input Voltage
0.8V
OUT
V
Note 1: Start-up voltage operation is guaranteed without the addition of an external Schottky diode between the in-
put and output.
Note 2: Steady-state output current indicates that the device maintains output voltage regulation under load.
Note 3: Device is bootstrapped (power to the IC comes from OUT). This correlates directly with the actual battery
supply.
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TYPICAL PERFORMANCE CHARACTERISTICS
0.01
0.1
1
10
100
1000
0
10
20
30
40
50
60
70
80
90
100
Fig. 1 V
OUT
=3.3V CLSEL=OUT (0.8A)
V
IN
=2.4V
V
IN
=1.2V
Efficiency (%)
Loading (mA)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0
20
40
60
80
100
120
140
160
I_limit=0.45A , V
OUT
=3.3V
Input
B
attery
C
urrent (
µ
A)
Input battery voltage (V)
Fig. 2 No-Load Battery Current vs. Input Battery Voltage
I_limit=0.8A , V
OUT
=3.3V
AIC1620/AIC1621/AIC1622
5
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TYPICAL PERFORMANCE CHARACTERISTICS
(Continued)
0.01
0.1
1
10
100
1000
Fig. 3 V
OUT
=3.3V CLSEL=GND (0.45A)
Efficiency (%)
Loading (mA)
40
50
60
70
80
90
100
V
IN
=2.4V
V
IN
=1.2V
0.01
0.1
1
10
100
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
Fig. 4 Start-up Voltage vs. Load Current
Without Diode
With Diode
Start-up Voltage (V)
Load Current (mA)
1.0
1.5
2.0
2.5
3.0
3.5
4.0
-0.10
-0.08
-0.06
-0.04
-0.02
0.00
0.02
0.04
0.06
0.08
0.10
Fig. 5 Shutdown Current vs. V
OUT
Shutdown Current (
µ
A)
V
OUT
(V)
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
Fig. 6 Shutdown Threshold vs. Output Voltage
Shutdown Threshold (V)
Output Voltage (V)
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
0
100
200
300
400
500
600
700
800
Fig. 7 Maximum Output Current vs. Input Voltage
CLSEL=OUT
CLSEL=GND
Maximum Output Current (
mA)
Input Voltage (V)
V
OUT
=3.3V
Fig. 8 Heavy Load Waveform
LX pin waveform
V
OUT
AC Couple
Inductor Current
V
IN
=2.4V
V
OUT
=3.3V
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