AIC1638
1-Cell, 3-Pin, Step-Up DC/DC Converter
FEATURES
A Guaranteed Start-Up from less than 0.9 V.
High Efficiency.
Low Quiescent Current.
Less Number of External Components needed.
Low Ripple and Low Noise.
Fixed Output Voltage: 2.7V, 3.0V, 3.1V, 3.3V,
4.5V and 5V.
Space Saving Packages: SOT-23, SOT-89 and
TO-92.
DESCRIPTION
The AIC1638 is a high efficiency step-up DC/DC
converter for applications using 1 to 4 NiMH
battery cells. Only three external components are
required to deliver a fixed output voltage of 2.7V,
3.0V, 3.1V, 3.3V, 4.5V or 5V. The AIC1638 starts
up from less than 0.9V input with 1mA load. Pulse
Frequency Modulation scheme brings optimized
performance for applications with light output
loading and low input voltages. The output ripple
and noise are lower compared with the circuits
operating in PSM mode.
The PFM control circuit operating in 100KHz
(max.) switching rate results in smaller passive
components. The space saving SOT-23, SOT-89
and TO-92 packages make the AIC1638 an ideal
choice of DC/DC converter for space conscious
applications, like pagers, electronic cameras, and
wireless microphones.
APPLICATIONS
Pagers.
Cameras.
Wireless Microphones.
Pocket Organizers.
Battery Backup Suppliers.
Portable Instruments.
■
TYPICAL APPLICATION CIRCUIT
V
IN
L1
100μH
D1
GS SS12
AIC1638-27
AIC1638-30
AIC1638-31
AIC1638-33
AIC1638-45
AIC1638-50
V
OUT
+
C1
SW
22μF
VOUT
+ C2
47μF
GND
One Cell Step-Up DC/DC Converter
Analog Integrations Corporation
Si-Soft Research Center
3A1, No.1, Li-Hsin Rd. I , Science Park , Hsinchu 300, Taiwan , R.O.C.
TEL: 886-3-5772500
FAX: 886-3-5772510
www.analog.com.tw
DS-1638G-01
20100121
1
AIC1638
ORDERING INFORMATION
AIC1638-XX X X XX
P AC KING TY PE
TR : TAP E & RE EL
B G : BA G
P AC KA G E TY PE
X : S OT-8 9
Z: TO -92
U : SO T-23
C : Com mercia l
P : Le ad Fre e Com me rcial
G : G ree n P acka ge
O UTP UT
2 7:
3 0:
31 :
3 3:
4 5:
5 0:
E xamp le:
AIC1 638 -2 7PX TR
2.7V V ersion , in SO T-89 L ead Fre e
P ackage & Ta pe & Ree l P acking Typ e
AIC1 638 -2 7G XTR
2.7V V ersion , in SO T-89 G ree n P acka ge
& Tap e & Reel P acking Type
V OL TAG E
2 .7V
3 .0V
3 .1V
3 .3V
4 .5V
5 .0V
PIN CONF IG URAT IO N
S OT-89
TO P V IE W
1: G ND
2: V O UT
3: S W
1
2
3
TO -92
TO P V IE W
1: G ND
2: V O UT
3: S W
1
2
3
S O T-2 3
TO P VIE W
1 : G ND
2: SW
3 : V O UT
1
3
2
SOT-23 MARKING
Part No.
AIC1638-27
AIC1638-30
AIC1638-31
AIC1638-33
AIC1638-45
AIC1638-50
SOT-89 MARKING
Part No.
AIC1638-27XX
AIC1638-30XX
AIC1638-31XX
AIC1638-33XX
AIC1638-45XX
AIC1638-50XX
CX
AN27
AN30
AN31
AN33
AN45
AN50
PX
AN27P
AN30P
AN31P
AN33P
AN45P
AN50P
GX
AN27G
AN30G
AN31G
AN33G
AN45G
AN50G
CU
DA27
DA30
DA31
DA33
DA45
DA50
PU
DA27P
DA30P
DA31P
DA33P
DA45P
DA50P
GU
DA27G
DA30G
DA31G
DA33G
DA45G
DA50G
2
AIC1638
ABSOLUATE MAXIMUM RATINGS
Supply Voltage (VOUT pin)
SW pin Voltage
SW pin Switch Current
Operating Temperature Range
Maximum Junction Temperature
Storage Temperature Range
Lead Temperature (Soldering 10 Sec.)
Thermal Resistance Junction to Case
SOT-23
TO-92
SOT-89
Thermal Resistance Junction to Ambient
(Assume no ambient airflow, no heatsink)
SOT-23
TO-92
SOT-89
.6V
6V
0.6A
-40°C to 85°C
125°C
-65°C to 150
°C
260°C
130°C/W
120°C/W
30°C/W
180°C/W
150°C/W
160°C/W
Absolute Maximum Ratings are those values beyond which the life of a device may be impaired.
TEST CIRCUIT
I
IN
V
IN
D1
SS12
V
OUT
L1
100μH
AIC1638
+
C1
SW
22μF
GND
VOUT
+ C2
47μF
Fig. 1 Test Circuit 1
IS
AIC1638
VOUT
GND
SW
VSW
V
S
AIC1638
100
VOUT
GND
SW
F
OSC
VS
Fig. 2 Test Circuit 2
Fig. 3 Test Circuit 3
3
AIC1638
ELECTRICAL CHARACTERISTICS
PARAMETER
TEST CONDITIONS
V
S
=V
OUT
x 0.95
Oscillator Duty Cycle
Measurement of the SW
pin waveform
V
S
=V
OUT
x 0.95
Max. Oscillator Freq.
Efficiency
Measurement of the SW
pin waveform
3
1
F
OSC
η
80
105
85
130
KHz
%
3
DUTY
65
75
85
%
(Continued)
TEST
CKT
SYMBOL
MIN.
TYP.
MAX.
UNIT
Note 1:
Specifications are production tested at T
A
=25°C. Specifications over the -40°C to 85°C operating
temperature range are assured by design, characterization and correlation with Statistical Quality
Controls (SQC).
TYPICAL PERFORMANCE CHARACTERISTICS
Capacitor (C2) : 47μF (Tantalum Type)
Diode
(D1) : 1N5819 Schottky Type
2.8
85
80
(Refer to Typical Application)
2.7
Output Voltage (V)
V
IN
=1.5V
V
IN
=1.2V
2.5
Efficiency (%)
2.6
V
IN
=1.8V
V
IN
=2.
0V
75
70
V
IN
=1.8V
V
IN
=2.0V
2.4
65
V
IN
=0.9V
2.3
60
V
IN
=1.5V
V
IN
=0.9V
2.2
0
55
V
IN
=1.2V
40
60
80
100
120
140
160
180
20
40
60
80
100
120
140
160
180
0
20
Output Current (mA)
Fig. 4 AIC1638-27 Load Regulation
(L=100μH CD54)
Output current (mA)
Fig. 5 AIC1638-27 Efficiency (L=100μH CD54)
2.8
85
80
2.7
75
Output Voltage (V)
2.6
Efficiency (%)
V
IN
=1.2V
2.5
V
IN
=1.5V
V
IN
=1.8V
V
IN
=2.0V
70
V
IN
=2.0V
65
60
V
IN
=1.8V
2.4
V
IN
=1.2V
55
V
IN
=1.5V
V
IN
=0.9V
V
IN
=0.9V
2.3
0
20
40
60
80
100
120
140
160
180
200
220
240
50
0
20
40
60
80
100
120
140
160
180
200
220 240
Output Current (mA)
Fig. 6
AIC1638-27 Load Regulation (
L=47μH CD54)
Output current (mA)
Fig. 7 AIC1638-27 Efficiency (L=47μH CD54)
5
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