AIC AIC164230XBG 3-pin one-cell step-up dc/dc converter Datasheet

AIC1642
3-Pin One-Cell Step-Up DC/DC Converter
■ DESCRIPTION
■ FEATURES
l
l
l
l
l
l
l
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, 3.3V, and 5V.
Space Saving Packages: SOT-89 and TO-92
The AIC1642 is a high efficiency step-up
DC/DC converter for applications using 1 to 4
battery cells. Only three external components
are required to deliver a fixed output voltage of
2.7V, 3.0V, 3.3V, or 5V. The AIC1642 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.
APPLICATIONS
■
l
l
l
l
l
l
Pagers.
Cameras.
Wireless Microphones.
Pocket Organizers.
Battery Backup Suppliers.
Portable Instruments.
The PFM control circuit operating in 100KHz
(max.) switching rate results in smaller passive
components. The space saving SOT-89 and
TO-92 packages make the AIC1642 is an ideal
choice of DC/DC converter for space conscious
applications, like pagers, electronic cameras,
and wireless microphones.
■ TYPICAL APPLICATION CIRCUIT
VIN
L1
100µH
+ C2
22µF SW
VOUT
D1
GS SS12
AIC1642-27
AIC1642-30
AIC1642-33
AIC1642-50
VOUT
+ C1
47µF
GND
One Cell Step-Up DC/DC Converter
Analog Integrations Corporation
4F, 9 Industry E. 9th Rd, Science-Based Industrial Park, Hsinchu, Taiwan
TEL: 886-3-5772500
FAX: 886-3-5772510
www.analog.com.tw
DS-1642-01 012102
1
AIC1642
■ ORDERING INFORMATION
AIC1642-XXCXXX
PIN CONFIGURATION
PACKING TYPE
TR: TAPE & REEL
TB: TUBE
BG: BAG
SOT-89
TOP VIEW
1: GND
2: VOUT
3: SW
PACKAGE TYPE
X: SOT-89
Z: TO-92
1
OUTPUT VOLTAGE
27: 2.7V
30: 3.0V
33: 3.3V
50: 5.0V
3
1
TO-92
TOP VIEW
1: GND
2: VOUT
3: SW
Example: AIC1642-27COTR
2
2
3
à 2.7V Version, in MSOP8 Package
& Tape & Reel Packing Type
■ ABSOLUATE MAXIMUM RATINGS
Supply Voltage
… … … … … … … … … … … … … … … … … … … … … … … … … … … … … … .12V
SW pin Voltage
… … … … … … … … … … … … … … … … … … … … … … … … … … … … … … .12V
SW pin Switch Current … … … … … … … … … … … … … … … … … … … … … … … … … … … 0.6A
Operating Temperature Range … … … … … … … … … … … … ..… … … … … .… .--40°C to 85°C
Storage Temperature Range … … … … … … … … … … … … … … … … … … … -65°C to 150 °C
Lead Temperature (Soldering 10 Sec.)
… … … … … … … … … … … … … … … … … … … 260°C
■ TEST CIRCUIT
AIC1642
100
2.5V
VOUT
SW
FOUT
GND
Oscillator Test Circuit
2
AIC1642
n
ELECTRICAL CHARACTERISTICS
(TA=25°C, IOUT=10mA, Unless otherwise
specified)
PARAMETER
TEST CONDITIONS
SYMBOL
VIN=1.8V, AIC1642-27
Output Voltage
VIN=1.8V, AIC1642-30
VIN=2.0V, AIC1642-33
VOUT
VIN=3.0V, AIC1642-50
Input Voltage
TYP.
MAX.
2.633
2.700
2.767
2.925
3.000
3.075
3.218
3.300
3.382
4.875
5.000
5.125
VIN
Start-Up Voltage
IOUT=1mA, VIN:0→2V
VSTART
Hold-on Voltage
IOUT=1mA, VIN:2→0V
VHOLD
No-Load Input Current
IOUT=0mA
Supply Current
MIN.
0.8
AIC1642-27
42
AIC1642-30
50
AIC1642-33
60
AIC1642-50
V
8
V
0.9
V
0.7
V
µA
15
IIN
UNIT
IDD1
90
µA
IDD2
8
µA
VIN=VOUT x 0.95
Measurement of the IC input
current (VOUT pin)
VIN=VOUT + 0.5V
Supply Current
Measurement of the IC input
current (VOUT pin)
SW Leakage Current
VSW =10V, VIN=VOUT + 0.5V
SW Switch-On Resistance
0.5
AIC1642-27
2.2
AIC1642-30
2.1
AIC1642-33
Ω
2.0
RON
AIC1642-50
µA
1.9
VIN=VSW x 0.95, VSW =0.4V
VIN=VOUT x 0.95
Oscillator Duty Cycle
Measurement of the SW Pin
Waveform
DUTY
65
75
85
%
FOSC
80
105
130
KHz
VIN=VOUT x 0.95
Max. Oscillator Freq.
Efficiency
Measurement of the SW Pin
Waveform
η
80
%
3
AIC1642
TYPICAL PERFORMANCE CHARACTERISTICS
Capacitor (C1) : 47 µ F (Tantalum Type)
Diode (D1) : 1N5819 Schottky Type
85
2.8
80
VIN=2.0V
2.6
75
Efficiency (%)
Output voltage (V)
2.7
VIN=1.8V
VIN=1.5V
VIN=1.2V
2.5
VIN=2.0V
70
VIN=1.8V
VIN=1.5V
65
2.4
VIN=1.2V
60
VIN=0.9V
2.3
VIN=0.9V
55
2.2 0
20
40
60
80
100
120
140
160
180
0
20
40
60
80
100
120
140
160
Output Current (mA)
Output current (mA)
Fig. 1 AIC1642-27 Load Regulation (L=100µH CD54)
Fig. 2 AIC1642-27 Efficiency (L=100µH CD54)
1.0
180
2.78
0.9
2.76
Start up
0.7
Output Voltage VOUT (V)
Input Voltage (V)
0.8
0.6
0.5
Hold on
0.4
0.3
0.2
2.74
No Load
2.72
2.70
2.68
2.66
2.64
0.1
0.0
0
Fig. 3
2
4
6
8
10
12
14
16
18
2.62
-40
160
82
140
80
120
100
80
60
40
-20
0
20
40
60
80
100
Temperature (°C)
Fig. 4 AIC1642-27 Output Voltage vs. Temperature
Output Current (mA)
AIC1642-27 Start-up & Hold-on Voltage (L=100µH)
Maximum Duty Cycle (%)
Switching Frequency (kHz)
n
78
76
74
72
70
68
20
-40
-20
Fig. 5
Temperature (°C)
AIC1642-27 Switching Frequency vs. Temperature
0
20
40
60
80
100
66
-40
Fig. 6
-20
0
20
40
60
80
100
Temperature (°C)
AIC1642-27 Maximum Duty Cycle vs. Temperature
4
AIC1642
3.2
52
2.8
48
Supply Current IDD1 (µA)
SW Turn On Resistance (Ω)
TYPICAL PERFORMANCE CHARACTERISTICS
2.4
2.0
1.6
1.2
0.8
0.4
(Continued)
44
40
36
32
28
24
0.0
-40
-20
Fig. 7
0
20
40
60
80
20
-40
100
Temperature (°C)
AIC1642-27 SW On Resistance vs. Temperature
-20
0
20
40
60
80
100
Temperature (°C)
AIC1642-27 Supply Current IDD1 vs. Temperature
Fig. 8
85
3.1
3.0
VIN=2.0V
80
2.8
VIN=.8V
VIN=1.5V
75
Efficiency (%)
Output voltage VOUT(V)
2.9
2.7
2.6
2.5
2.4
VIN=1.2V
2.3
VIN=2.0V
70
VIN=1.8V
65
VIN=1.5V
60
2.2
2.0
0
10
20
30
40
VIN=1.2V
55
VIN=0.9
2.1
VIN=0.9V
50
60
70
80
90
50
100 110 120 130 140
0
Output Current (mA)
Fig. 9 AIC1642-30 Load Regulation (L=100µH CD54)
20
Fig. 10
1.0
40
60
80
100
120
140
160
180
Output Current (mA)
AIC1642-30 Efficiency (L=100µH CD54)
3.06
0.9
Start up
3.04
Output Voltage Vout (V)
0.8
Input Voltage (V)
n
0.7
0.6
0.5
Hold on
0.4
0.3
0.2
0.1
0.0
No Load
3.02
3.00
2.98
2.96
2.94
2.92
0
2
4
6
8
10
12
14
16
18
20
Output Current (mA)
Fig. 11 AIC1642-30 Start-up & Hold-on Voltage (L=100µH)
2.90
-40
-20
0
20
40
60
80
100
Temperature (°C)
Fig. 12 AIC1642-30 Output Voltage vs. Temperature
5
AIC1642
160
82
140
80
Maximum Duty Cycle (%)
Switching Frequency (kHz)
TYPICAL PERFORMANCE CHARACTERISTICS
120
100
80
60
40
20
-20
0
20
40
60
80
78
76
74
72
70
66
-40
100
Temperature (°C)
Fig. 13 AIC1642-30 Switching Frequency vs. Temperature
3.2
52
2.8
48
2.4
2.0
1.6
1.2
0.8
-20
0
20
40
60
80
100
Temperature (°C)
Fig. 14 AIC1642-30 Maximum Duty Cycle vs. Temperature
Supply Current IDD1 (µA)
SW Turn On Resistance (Ω)
(Continued)
68
0
-40
44
40
36
32
28
24
0.4
0.0
-40
-20
0
20
40
60
80
100
20-40
-20
0
20
40
60
80
100
Temperature (°C)
Fig. 16 AIC1642-30 Supply Current vs. Temperature
Temperature (°C)
Fig. 15 AIC1642-30 SW On Resistance vs. Temperature
90
3.4
3.3
85
VIN=2.0V
3.2
3.1
VIN=1.5V
80
VIN=1.8
Efficiency (%)
Output Voltage (V)
n
3.0
VIN=1.2
2.9
2.8
2.7
2.6
VIN=2.0V
75
70
VIN=1.8V
VIN=1.5V
65
VIN=1.2V
60
2.5
2.4
55
VIN=0.9
2.3
VIN=0.9V
50
0
25
50
75
100
125
150
175
200
Output Current (mA)
Fig. 17 AIC1642-33 Load Regulation (L=100µH CD54)
0
25
50
75
100
125
150
175
200
Output Current (mA)
Fig. 18 AIC1642-33 Efficiency (L=100µH CD54)
6
AIC1642
TYPICAL PERFORMANCE CHARACTERISTICS
1.1
3.45
0.9
Output Voltage VOUT (V)
Start up
Input Voltage (V)
0.8
0.7
0.6
0.5
0.4
0.3
Hold on
3.40
3.30
3.25
3.20
3.15
3.10
0.1
3.05
0
Fig. 19
2
4
6
8
10
12
14
16
18
20
No Load
3.35
0.2
0.0
3.00
-40
-20
0
20
40
60
80
100
Temperature (°C)
Fig. 20 AIC1642-33 Output Voltage vs. Temperature
Output Current (mA)
AIC1642-33 Start-up & Hold-on Voltage (L=100µH)
150
82
Maximum Duty Cycle (%)
140
Switching Frequency (KHz)
(Continued)
3.50
1.0
130
120
110
100
90
80
70
80
78
76
74
72
70
68
60
50
-40
-20
0
20
40
60
80
66
-40
100
-20
0
20
40
60
80
100
Temperature (°C)
Fig. 21 AIC1642-33 Switching Frequency vs. Temperature
Temperature (°C)
Fig. 22 AIC1642-33 Maximum Duty Cycle vs. Temperature
3.2
60
2.8
56
Supply Current IDD1 (µA)
SW Turn On Resistance (Ω)
n
2.4
2.0
1.6
1.2
0.8
0.4
52
48
44
40
36
32
28
0.0
-40
-20
Fig. 23
0
20
40
60
80
100
Temperature (°C)
AIC1642-33 SW On Resistance vs. Temperature
24
-40
-20
0
20
40
60
80
100
Temperature (°C)
Fig. 24 AIC1642-33 Supply Current vs. Temperature
7
AIC1642
TYPICAL PERFORMANCE CHARACTERISTICS
5.5
85
VIN=3.0V
4.5
80
VIN=2.0V
Efficiency (%)
Output Voltage (V)
(Continued)
90
5.0
4.0
VIN=1.5V
3.5
3.0
VIN=1.2V
75
VIN=3.0V
70
VIN=2.0V
65
VIN=1.5V
60
VIN=0.9V
2.5
55
VIN=0.9
2.0
VIN=1.2
50
1.5
0
50
100
150
200
250
300
350
45
400
0
50
100
150
Output Current (mA)
Fig. 25
AIC1642-50 Load Regulation ( L=100µH CD54)
5.3
1.6
5.2
Output Voltage Vout (V)
Input Voltage (V)
Fig. 26
1.8
1.2
Start up
1.0
0.8
0.6
Hold on
0.4
200
250
300
350
400
Output Current (mA)
1.4
0.2
AIC1642-50 Efficiency (L=100µH, CD54)
No Load
5.1
5.0
4.9
4.8
4.7
4.6
4.5
0.0
0
2
Fig. 27
4
6
8
10
12
14
16
18
4.4
-40
20
Output Current (mA)
AIC1642-50 Start-up & Hold-on Voltage (L=100µH)
150
82
140
80
130
120
110
100
90
80
70
60
-40
-20
20
40
60
80
100
78
76
74
72
70
68
66
-20
0
20
40
60
80
100
64
-40
Temperature (°C)
Fig. 29
0
Temperature (°C)
Fig. 28 AIC1642-50 Output Voltage vs. Temperature
Maximum Duty Cycle (%)
Switching Frequency (KHz)
n
AIC1642-50 Switching Frequency vs. Temperature
-20
0
20
40
60
80
100
Temperature (°C)
Fig. 30
AIC1642-50 Maximum Duty Cycle vs. Temperature
8
AIC1642
TYPICAL PERFORMANCE CHARACTERISTICS
3.2
100
2.8
90
Supply Current IDD1 (µA)
SW Turn On Resistance (Ω)
n
2.4
2.0
1.6
1.2
0.8
0.4
(Continued)
80
70
60
50
40
30
20
0.0
-40
-20
0
20
40
60
80
100
Temperature (°C)
Fig. 31 AIC1642-50 SW On Resistance vs. Temperature
10
-40
-20
0
20
40
60
80
100
Temperature (°C)
Fig. 34 AIC1642-50 Supply Current vs. Temperature
■ BLOCK DIAGRAM
SW
1.25V REF.
VOUT
1M
+
Enable
GND
OSC, 100KHz
■ PIN DESCRIPTIONS
PIN1 : GND - Ground. Must be low impedance; sorer directly to ground
plane.
PIN3 : SW – Internal drain of N-MOSFET
switch.
PIN2 : VOUT - IC supply pin. Connect VOUT
to the regulator output.
9
AIC1642
■ APPLICATION INFORMATION
GENERAL DESCRIPTION
AIC1642 PFM (pulse frequency modulation) control-
tinuous conduction mode. Continuous conduction
mode means that the inductor current does not
ramp to zero during each cycle.
ler ICs combine a switch mode regulator, N-channel
power MOSFET, precision voltage reference, and
VIN
voltage detector in a single monolithic device. They
IIN
offer extreme low quiescient current, high efficiency,
ID
and very low gate threshold voltage to ensure start-
IOUT
SW
up with low battery voltage (0.8V typ.). Designed to
VOUT
+
maximize battery life in portable products, and
minimize switching losses by only switching as
EXT
Isw
Ico
needed service the load.
PFM controllers transfer a discrete amount of energy per cycle and regulate the output voltage by
VEXT
modulating switching frequency with the constant
turn-on time. Switching frequency depends on load,
input voltage, and inductor value, and it can range
up to 100KHz. The SW on-resistance is typically 1.9
IIN
IPK
to 2.2Ω to minimize switch losses.
When the output voltage drops, the error comparator enables 100kHz oscillator that turns on the
ISW
MOSFET around 7.5us and 2.5us off time. Turning
on the MOSFET allows inductor current to ramp up,
storing energy in a magnetic field. When MOSFET
turns off that force inductor current through diode to
Charge Co.
ID
IOUT
the output capacitor and load. As the stored energy
is depleted, the current ramp down until the diode
VSW
TDIS
Discharge Co.
turns off. At this point, inductor may ring due to residual energy and stray capacitance. The output cat
pacitor stores charge when current flowing through
the diode is high, and release it when current is low,
Discontinuous Conduction Mode
thereby maintaining a steady voltage across the
load.
As the load increases, the output capacitor discharges faster and the error comparator initiates cycles sooner, increasing the switching frequency.
The maximum duty cycle ensure adequate time for
energy transfer to output during the second half
each cycle. Depending on circuit, PFM controller
can operate in either discontinuous mode or con-
10
AIC1642
In the continuous mode, the switching frequency is
VEXT
1 (VOUT + VD − VIN )
TON (VOUT + VD − VSW )
x
VIN − VSW
* [1 + (
)]
2 VOUT + VD − VSW
1  VOUT + VD − VIN 
≅


TON  VOUT + VD − VSW 
fSW =
IIN
IPK
ISW
where Vsw = switch drop and proportion to output current.
ID
IOUT
Inductor Selection
To operate as an efficient energy transfer element, the inductor must fulfill three require-
VSW
ments. First, the inductance must be low
enough for the inductor to store adequate ent
ergy under the worst case condition of minimum
input voltage and switch ON time. Second, the
inductance must also be high enough so maxi-
Continuous Conduction Mode
mum current rating of AIC1642 and inductor are
not exceed at the other worst case condition of
maximum input voltage and ON time. Lastly, the
Continuous Conduction Mode
inductor must have sufficiently low DC resis-
At the boundary between continuous and dis-
tance so excessive power is not lost as heat in
continuous mode, output current (IOB) is deter-
the windings. But unfortunately this is inversely
related to physical size.
mined by
Minimum and maximum input voltage, output
 VIN  1 VIN
IOB = 
* TON * (1 − x )
* *
 VOUT  2 L
voltage and output current must be established
in advance and then inductor can be selected.
In discontinuous mode operation, at the end of
where Vd is the diode drop,
the switch ON time, peak current and energy in
TON
x = (RON + RS ) *
L
the inductor build according to
RON= Switch turn on resistance, RS= Inductor
DC resistance
TON = Switch ON time
In the discontinuous mode, the switching frequency (Fsw) is
Fsw =
2 * (L) * (VOUT + VD − VIN) * (IOUT)
VIN 2 × TON 2
(1 + x )
RON + Rs
 VIN  

IPK = 
* TON) 
 * 1 − exp( −
L
 RON + Rs  

x
 VIN 

≅
 * (TON ) * 1 − 
2
 L 

≅
VIN
TON
L
(simple loss equation),
where x = (RON + RS ) *
TON
L
11
AIC1642
EL =
 VOUT+ VD − VSW x 
 VIN− VSW
 x
IPK = 
−  * IOUT+ 
 * TON * 1− 
V
IN
−
V
SW
2
2L




 2
1
L × Ipk 2
2
Power required from the inductor per cycle must
be equal or greater than
PL/fSW = (VOUT + VD − VIN) * (IOUT) * (
Valley current (Iv) is
 VOUT+ VD − VSW x 
 VIN − VSW
 x
IV = 
−  * IOUT− 
 * TON* 1− 
2
2L 
 VIN − VSW

 2
1
)
fsw
In order for the converter to regulate the output.
When loading is over IOB, PFM controller operates in continuous mode. Inductor peak current
can be derived from
Table 1 Indicates resistance and height for each coil.
Power Inductor Type
Coilcraft SMT Type
DS1608
(www.coilcraft.com)
DO3316
Sumida SMT Type CD54
Hold SMT Type PM54
Hold SMT Type PM75
Inductance
( µH )
Resistance ( Ω )
Rated Current
Height
(A)
(mm)
22
0.10
0.7
47
0.18
0.5
100
0.38
0.3
22
0.08
2.7
47
0.14
1.8
47
0.25
0.7
100
0.50
0.5
47
0.25
0.7
100
0.50
0.5
33
0.11
1.2
Capacitor Selection
2.9
5.2
4.5
4.5
5.0
Most of the input supply is supplied by the input
A poor choice for an output capacitor can result in
bypass capacitor, the capacitor voltage rating
poor efficiency and high output ripple. Ordinary
should be at least 1.25 times greater than a
aluminum electrolytic, while inexpensive may
maximum input voltage.
have unacceptably poor ESR and ESL. There are
low ESR aluminum capacitors for switch mode
DC-DC converters which work much well than
general unit. Tantalum capacitors provide still better performance at more expensive. OS-CON capacitors have extremely low ESR in a small size.
If capacitance is reduced, output ripple will increase.
Diode Selection
Speed, forward drop, and leakage current are the
three main considerations in selecting a rectifier
diode. Best performance is obtained with Schottky rectifier diode such 1N5819. Motorola makes
MBR0530 in surface mount. For lower output
power a 1N4148 can be used although efficiency
and start-up voltage will suffer substantially.
12
AIC1642
VD = Diode drop.
Component Power Dissipation
The power dissipated in a switch loss is
Operating in discontinuous mode, power loss in
PDSW =
the winding resistance of inductor can be ap-
2  TON 
 VOUT + VD − VIN 

 * (RON) * 
 * (POUT )
3 L 
VOUT


proximate equal to
PD L =
2  TON 
 VOUT + VF 

 * (RD ) * 
 * (POUT )
3 L 
 VOUT 
The power dissipated in rectifier diode is
 VD 
PDd = 
 * (POUT )
 VOUT 
where POUT=VOUT * IOUT; RS=Inductor DC R;
■ PHYSICAL DIMENSIONS
l
SOT-89 (unit: mm)
D
A
SYMBOL
MIN
MAX
C
A
1.40
1.60
B
0.36
0.48
C
0.35
0.44
D
4.40
4.60
D1
1.62
1.83
E
2.29
2.60
D1
H
E
L
B
e
e1
l
e
1.50 (TYP.)
e1
3.00 (TYP.)
H
3.94
4.25
L
0.89
1.20
SOT-89 MARKING
Part No.
Marking
AIC1642-27
AM27
AIC1642-30
AM30
AIC1642-33
AM33
AIC1642-50
AM50
13
AIC1642
l
TO-92 (unit: mm)
A
E
L
C
SYMBOL
MIN
MAX
A
4.32
5.33
C
e1
D
0.38 (TYP.)
D
4.40
5.20
E
3.17
4.20
e1
1.27 (TYP.)
14