AIC1628
High-Efficiency, Step-Up DC/DC Controller
Analog Integrations Corporation 4F, 9 Industry E. 9th Rd, Science-Based Industrial Park, Hsinchu, Taiwan
DS-168-01 012102
TEL: 886-3-5772500
FAX: 886-3-5772510
www.analog.com.tw
1
n
FEATURES
l
4V to 20V Input Voltage Operation.
l
Adjustable Output Voltage.
l
Low Quiescent Current at 100
A.
l
Pulse-Skipping and Pulse-Frequency Modulation
Maintain High Efficiency (max. 95%).
l
90KHz to 250KHz Oscillator Frequency.
l
Power-Saving Shutdown Mode (8
A Typical).
l
Push-Pull Driver Output.
l
V
REF
Pin Available.
l
Current Limit Function Available.
n
APPLICATIONS
l
Flash Memory Programming Power Supply.
l
Positive LCD Contrast Bias for Notebook & Palm-
top Computers.
l
Step-Up DC/DC Converter Module.
l
Telecom Power Supply.
n
DESCRIPTION
The AIC1628 is a high performance step-up
DC/DC controller, designed to drive an external
power switch to generate programmable positive
voltages. In the particularly suitable LCD contrast
bias and flash memory programming power
supply applications, typical full-load efficiencies
are 85% to 95%. 4V to 20V input operation range
allows the AIC1628 to be powered directly by the
battery pack in the most battery-operated appli-
cations for greater efficiency. Output voltage can
be scaled to 40V or greater by two external re-
sistors. A Pulse-Frequency Modulation scheme
is employed to maintain high efficiency conver-
sion under wide input voltage range. Quiescent
current is about 100
A and can be reduced to
8
A in shutdown mode. Switching frequency be-
ing around 90KHz to 250KHz range, small size
switching components are ideal for battery pow-
ered portable equipments, like notebook and
palmtop computers.
n
TYPICAL APPLICATION CIRCUIT
AIC1628
CL
DHI
DLOW
F B
GND
SHDN
VIN
VREF
+36V
>50mA
V
OUT
GS SS14
C5
+
C6
V
IN
+5V ~ 20V
C1
220
F
+
5V
*Buss Fuse MCR-2A
**Sumida CDR105
*Fuse
60m
68
H
0.047
F
C2
R1
470K
R2
16.5K 0.033
F
C3
220
F
0.1
F
D1
CEA3055L
0.01
F
C4
**L1
Q1
Load Current (mA)
Efficiency (%)
80
85
90
95
0
50
100
150
200
V
IN
=18V
V
IN
=9V
V
IN
=5V
V
OUT
=36V
V
IN
=13V
Color LCD Contrast Bias Supply
Efficiency vs. Output Current
AIC1628
2
n
ORDERING INFORMATION
AIC1628 CXXX
PACKING TYPE
TR: TAPE & REEL
TB: TUBE
PACKAGE TYPE
N: PLASTIC DIP
S: SMALL OUTLINE
PIN CONFIGURATION
DIP-8
SO-8
TOP VIEW
DLOW
1
3
4
2
8
6
5
7
CL
VREF
SHDN
FB
DHI
GND
VIN
EX: AIC1628CSTR
in SO8 Package & Tape & Reel Packing Type
(CN is not available in TR packing type.)
n
ABSOLUTE MAXIMUM RATINGS
VIN Supply Voltage (V
IN
Pin) .............................. ... ... ... ... .............................................. 20V
SHDN
Pin Voltage............................................ ... ... ... ... ................................................15V
Operating Temperature Range ............................ ... ... ... ....................................... 0
C~70
C
Storage Temperature Range ............................. ... ... ... .................................. -65
C~ 150
C
n
TEST CIRCUIT
Refer to Typical Application Circuit
n
ELECTRICAL CHARACTERISTICS
(V
IN
= 13V, T
A
=25
C, unless otherwise
specified.)
PARAMETERS
TEST CONDITIONS
MIN.
TYP.
MAX.
UNIT
Input Voltage
4
20
V
Quiescent Current
V
FB
= 1.5V
100
200
A
Shutdown Mode Current
V
SHDN
= 0V
8
20
A
V
REF
Voltage
I
SOURCE
= 250
A
1.16
1.22
1.28
V
V
REF
Source Current
250
A
DLOW "ON Resistance"
15
DHI "ON Resistance"
10
CL Threshold
V
IN
- V
CL
50
70
90
mV
Shutdown Threshold
0.8
1.5
2.4
V
Shutdown Input Leakage
Current
V
SHDN
< 15V
1
A
AIC1628
3
n
TYPICAL PERFORMANCE CHARACTERISTICS
Fig. 1 Frequency vs. V
IN
Voltage
V
IN
(V)
4
9
14
19
24
80
130
180
230
280
T
A
= 0
C
T
A
= 25
C
T
A
= 70
C
Frequency (KHz)
Fig. 2 Duty Cycle vs. V
IN
Voltage
100
V
IN
(V)
30
40
50
60
70
80
90
4
9
14
19
24
Duty Cycle (%)
T
A
= 0
C
T
A
= 25
C
T
A
= 70
C
Fig. 3 Quiescent Current vs. V
IN
Voltage
60
70
80
90
100
110
4
9
14
19
24
V
IN
(V)
Quiescent Current (
A)
T
A
= 0
C
T
A
= 25
C
T
A
= 70
C
Fig. 4 Current Limit Threshold vs. Temperature
Temperature (
C)
CL Threshold (mV)
0
20
40
60
80
50
55
60
65
70
75
V
IN
= 5V
V
IN
= 20V
V
IN
= 13V
Fig. 5 Reference Voltage vs. Temperature
0
20
40
60
80
1.1
1.15
1.2
1.25
1.3
Temperature (
C)
Reference Voltage (V)
V
IN
= 5V
AIC1628
4
n
BLOCK DIAGRAM
+
-
+
-
ERROR COMPARATOR
LATCH
CURRENT LIMIT
COMPARATOR
1.22V
REFERENCE
VOLTAGE
PFM
OSCILLATOR
VREF
VIN
SHDN
4
3
2
1
FB
OUTPUT DRIVER
V
IN
VIN
60mV
DHI
DLOW
CL
8
7
6
5
GND
n
PIN DESCRIPTIONS
PIN 1: VIN
- Input supply voltage is from 4V to
20V.
PIN 2: VREF - Reference output is 1.22V. By-
pass with a 0.047
F capacitor to
GND. Sourcing capability is
guaranteed to be greater than
250
A.
PIN 3:
SHDN
- Logical input to shutdown the
chip.
>1.5V = normal operation,
GND = Shutdown,
Can not be floating or forced
greater than 15V. In shutdown
mode DLOW and DHI pins are at
low level.
PIN 4: FB
- Feedback signal input to sense
VREF. Connecting a resistor R1
to V
OUT
and a resistor R2 to GND
yields the output voltage:
V
OUT
= (R1+R2)/R2 x V
REF
(Refer to typical application cir-
cuit)
PIN 5: GND - Power ground.
PIN 6: DLOW- Connected to gate of the external
N-channel MOSFET or base of
the NPN bipolar transistor.
PIN 7: DHI
- Driver sourcing output. Connect-
ed to DLOW when using an ex-
ternal N-channel MOSFET.
When using an external NPN bi-
polar transistor, connect a base
resistor RB from this pin to
DLOW. RB value depends on V
IN
,
inductor and NPN current gain.
PIN 8: CL
- Current-limit input. Threshold
voltage is 60mV from V
IN
. This
pin clamps the switch peak cur-
rent to prevent over-current dam-
age to the external switch, under
abnormal conditions.
AIC1628
5
n
APPLICATION EXAMPLES
* Buss Fuse MCR-2A
** Sumida RCH108
AIC1628
CL
DHI
DLOW
FB
SHDN
VIN
VREF
CEA3055L
Q1
+12V
V
OUT
D1
GS SS14
3
3
0
F
C3
+
*Fuse
60m
**L1
47
H
GND
R1
100K
R2
11.3K
C2
0.047
F
V
IN
+5V ~ 11V
C1
220
F
+
Load Current (mA)
Efficiency (%)
0
50
100
150
200
250
300
350
85
90
95
100
V
IN
=11V
V
IN
=9V
V
IN
=7V
V
IN
=5V
Efficiency vs. Load Current
Fig. 6 Flash memory programming supply
Battery
Powered
220
F
*L1
47
H
V
I N
1
+2V~ 5V
+
C1
150
F
+12V
D1 GS SS14
V
OUT
*Sumida RCH108
+
C4
AIC1628
CL
DHI
DLOW
FB
GND
SHDN
VIN
VREF
+
C2
V
IN
2
5V
0.047
F
C3
33
F
CEA3055L
Q1
R2
11.3K
R 1
100K
Load Current (mA)
Efficiency
(%)
0
50
100
150
75
80
85
90
V
IN
1=2V
Efficiency vs. Load Current
V
IN
1=3V
V
IN
1=4V
Fig. 7 2-cells to +12V Flash memory programmer
C4
C 6
0.033
F
C5
0.1
F
RB
910
R2
20K
470K
C3
220
F
+
C2
0.047
F
0.1
F
*L1
150
H
+30V
D1 GS SS14
V
OUT
*Sumida CD54
AIC1628
CL
DHI
DLOW
FB
GND
SHDN
VIN
VREF
2SC4672
Q1
R 1
+
C 1
150
F
V
IN
+4V~6V
Load Current (mA)
Efficiency(%)
75
80
95
90
0
10
20
30
40
50
V
IN
=4V
Efficiency vs. Load Current
V
IN
=5V
V
IN
=6V
Fig. 8 4-cells to +30V power supply
PDF 
ZIP