AIC1896
1. 4MHz Thin Package
Current-Mode Step-Up DC/DC Converter
FEATURES
DESCRIPTION
Fixed Frequency 1.4MHz Current-Mode PWM
AIC1896 is a current-mode pulse-width modulation
Operation.
(PWM), step-up DC/DC Converter. The built-in high
Adjustable Output Voltage up to 30V.
voltage N-channel MOSFET allows AIC1896 for
Guaranteed 13V/ 200mA Output with 5V Input.
step-up applications with up to 30V output voltage,
2.5V to 10V Input Range.
as well as for Single Ended Primary Inductance
Maximum 0.1µA Shutdown Current.
Converter (SEPIC) and other low-side switching
Programmable Soft-Start.
DC/DC converter.
Tiny Inductor and Capacitors are allowed.
Space-Saving SOT-23-6 and TSOT-23-6
The high switching frequency (1.4MHz) allows the
Package.
use of small external components. The Soft-Start
function is programmable with an external capacitor,
APPLICATIONS
which sets the input current ramp rate.
White LED Backlight.
OLED Driver.
The AIC1896 is available in a space-saving
LCD Bias
SOT-23-6 and TSOT-23-6 package.
TYPICAL APPLICATION CIRCUIT
L
D1
3.3V or
4.2V
86
CH521S-30
C1
C3
ZD1
4.7µF
AIC1896
6
OFF ON
4
IN
LX
SHDN FB
SS GND
5
1
3
2
R2
ILED
1KΩ
R1
C2
84
1µF
BZV55-B12
11.8V~12.2V
62
0.033µF
82
Efficiency (%)
VIN
80
VIN=4.2V
78
VIN=3.3V
76
74
72
L: GTSK-51-150M (15µH)
L: GTSK-51-100M (10µH)
70
68
2
4
6
8
10
12
14
16
18
20
LED Current (mA)
Fig. 1 Li-Ion Powered Driver for three white LEDs
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-1896G-01
121208
1
AIC1896
L
D1
4.2V
80
CH521S-30
C1
ZD1
4.7µF
23.5V~24.5V
AIC1896
OFF ON
4
LX
IN
SHDN FB
SS GND
1
3
R2
ILED
1KΩ
2
5
76
1µF
BZV55-B24
6
78
C3
R1
C2
62
0.033µF
Efficiency (%)
VIN
3.6V or
74
72
VIN=4.2V
70
VIN=3.6V
68
66
64
L: GTSK-51-150M (15µH)
L: GTSK-51-100M (10µH)
62
60
2
4
6
8
10
12
14
16
18
20
LED Current (mA)
Fig. 2 Li-Ion Powered Driver for six white LEDs
ORDERING INFORMATION
AIC1896XXXX
PIN CONFIGURATION
PACKING TYPE
TR: TAPE & REEL
BG: BAG
PACKAGE TYPE
G: SOT-23-6
K: TSOT-23-6
P: LEAD FREE COMMERCIAL
G: GREEN PACKAGE
Example: AIC1896PKTR
SOT-23-6 / TSOT-23-6
FRONT VIEW
6
5
4
1: LX
2: GND
3: FB
1896/1896P
4: SHDN
5: SS
2
1
3
6: IN
Note: Pin1 is determined by orienting
the package marking as shown.
in Lead Free TSOT-23-6 Package & Tape
& Reel Packing Type
AIC1896PGTR
in Lead Free SOT-23-6 Package & Tape
& Reel Packing Type
TSOT-23-6 Marking
Part No.
Marking
AIC1896PK
896PK
AIC1896GK
896GK
SOT-23-6 Marking
Part No.
Marking
AIC1896PG
1896P
AIC1896GG
1896G
2
AIC1896
ABSOLUTE MAXIMUM RATINGS
LX to GND
-0.3V to +33V
FB to GND
-0.3V to +6V
IN, SHDN
-0.3V to +11V
SS to GND
-0.3V to +6V
0.6A
LX Pin RMS Current
Continuous Power Dissipation
727mW
Operating Temperature Range
-40°C to 85°C
125°C
Junction Temperature
Storage Temperature Range
-65°C to 150°C
Lead Temperature (soldering, 10s)
260°C
Absolute Maximum Ratings are those values beyond which the life of a device may be impaired.
TEST CIRCUIT
D1
L1
VIN
2.5V to 10V +
C1
10µF/16V
VOUT
GTSK-51-100M(10uH)
U1 AIC1896
6
4
SHDN
IN
LX
SHDN
FB
SS
SS14
C3
R1
1
C4
10µF
C5
1µF
3
GND
5
C2
0.033µF
+
2
R2
62
3
AIC1896
ELECTRICAL CHARACTERISTICS
(VIN=V SHDN =3V, FB=GND, SS=Open, TA=25°°C, unless otherwise specified) (Note 1)
PARAMETER
Input Supply Range
SYMBOL
CONDITIONS
VIN
VOUT
VIN Undervoltage Lockout
UVLO VIN rising, 50mV hysteresis
IIN
Shutdown Supply Current
TYP
2.5
Output Voltage Adjust Range
Quiescent Current
MIN
MAX UNITS
10
V
30
V
2.2
VFB = 1.3V, not switching
V
0.1
0.2
1
5
V SHDN = 0, TA = +25°C
0.01
0.5
µA
V SHDN = 0
0.01
10
µA
1.23
1.255
V
21
80
nA
0.05
0.20
%/V
1800
KHz
VFB = 1.0V, switching
mA
ERROR AMPLIFIER
Feedback Regulation Set Point
VFB
FB Input Bias Current
IFB
Line Regulation
1.205
VFB = 1.24V
2.6V < VIN < 5.5V
OSCILLATOR
Frequency
fOSC
1000
1400
Maximum Duty Cycle
DC
82
86
%
POWER SWITCH
Steady State Output Current
Io
Refer to Fig. 13
On-Resistance
RDS(ON) Vin = 5V
Leakage Current
ILX(OFF)
A
VLX = 30V, TA = +25°C
1
1.4
0.1
1
Ω
µA
VLX = 30V
10
Reset Switch Resistance
Guaranteed By Design
100
Ω
Charge Current
VSS = 1.2V
7.0
µA
0.3
V
SOFT-START
1.5
4
CONTROL INPUT
Input Low Voltage
VIL
V SHDN , VIN = 2.5V to 10V
Input High Voltage
VIH
V SHDN , VIN = 2.5V to 10V
SHDN Input Current
I SHDN
V SHDN = 1.8V
V SHDN = 0
1.0
V
25
50
0.01
0.1
µA
Note 1: Specifications are production tested at TA=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).
4
AIC1896
TYPICAL PERFORMANCE CHARACTERISTICS
1.50
TA=25°C
1.45
VIN=3.6V
Frequency (MHz)
Switching Frequency (MHz)
1.50
1.40
1.35
1.30
1.45
1.40
1.35
1.25
1.20
1.30
-40
-20
0
20
40
60
80
100
2
3
4
5
6
7
8
Temperature (°C)
10
11
10
11
Fig. 4 Frequency vs. Supply Voltage
5.50
1.7
1.6
VIN=3.6V
Output Voltage (V)
1.5
RDS(ON) (Ω)
9
Supply Voltage (V)
Fig. 3 Switching Frequency vs. Temperature
1.4
1.3
1.2
1.1
1.0
5.25
5.00
4.75
0.9
0.8
4.50
2
3
4
5
6
7
8
9
10
11
1
10
100
Output Current (mA)
Supply Voltage (V)
Fig. 6 Load Regulation (L1=10
Fig. 5 RDSON vs. Supply Voltage
μH)
12.5
2.4
VIN=3.6V
12.0
11.5
11.0
FB=1.0V
SHDN=1.0V
2.2
Supply Current (mA)
Output Voltage (V)
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
10.5
1
10
Output Current (mA)
100
μ
Fig. 7 Load Regulation (L1=22 H)
2
3
4
5
6
7
8
9
Supply Voltage (V)
Fig. 8 Switching Current
5
AIC1896
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
1.25
Supply Current (
μ
Feedback Voltage (V)
A)
90
85
FB=1.3V
SHDN=1.0V
80
75
70
65
2
3
4
5
6
7
8
9
10
1.24
1.23
1.22
1.21
VIN=3.6V
1.20
-50
11
-25
Supply Voltage (V)
Fig. 9 Non-Switching Current
25
50
75
100
90
VIN=4.2V
VIN=3.6V
VIN=3.3V
VIN=2.7V
VIN=2.5V
80
85
Efficiency (%)
85
Efficiency (%)
0
Temperature (°C)
Fig. 10 Feedback Pin Voltage
90
75
70
VOUT=5.0V
L1: GTSK-51-100M
65
VIN=4.2V
80
VIN=5.0V
VIN=3.6V
75
VIN=3.3V
70
VOUT=12V
L1: SLF6025-220MR
65
60
60
0
100
200
300
400
500
600
0
Output Current (mA)
Fig. 11 Efficiency vs. Output Current
(L1=10µH, test circuit refer to p.3)
50
100
150
200
Output Current (mA)
Fig. 12 Efficiency vs. output current
(L1=22µH, test circuit refer to p.3)
350
Maximum Output Current (mA)
800
Maximum Output Current (mA)
700
VOUT=13V
VOUT=5V
600
VOUT=9V
500
VOUT=15V
400
300
200
Maximum output current
defined at 90% of no load
output voltage
100
2
3
4
5
6
7
8
9
10
Supply Voltage (V)
Fig. 13(a) Maximum Output current vs. Supply Voltage
(L1: 10µH, test circuit refer to p.3)
300
VOUT=20V
250
VOUT=25V
200
150
VOUT=30V
100
Maximum output current
50
defined at 90% of no load
output voltage
0
3
4
5
6
7
8
9
10
11
Supply Voltage (V)
Fig. 13(b) Maximum Output Current vs. Supply Voltage
(L1:22µH, test circuit refer to p.3)
6
AIC1896
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
VLX
VSW
VOUT
VOUT
ILX
ILX
Fig. 14 Operation Wave Form
(VIN=5V; VOUT=12V, L1=22µH; R1=105K;
R2=12K;C3=1nF;IOUT=200mA, test circuit refer to p.3)
Fig. 15 Operation Wave Form
(VIN=3V;VOUT=5V;L1=10µH;R1=36K;R2=12K;
C3=39pF;IOUT=200mA, test circuit refer to p.3)
VOUT
VOUT
ILX
ILX
Fig. 16 Load Step Response
(VIN=3.3V; VOUT=5V;L1=10µH;IOUT=5mA to 200mA,
test circuit refer to p.3)
Fig. 17 Load Step Response
(VIN=5V ; VOUT=12V ;L1=22µH;IOUT=5mA to 150mA,
test circuit refer to p.3)
SHDN
VOUT
ILX
Fig. 18 Start-Up from Shutdown
(VIN=3.3V ;VOUT=13V ;RLOAD=300Ω,
test circuit refer to p.3)
7
AIC1896
BLOCK DIAGRAM
VIN
Control
PWM/PFM
I9
R3
Soft Start
R4
Error Amp
-
+
-
+
Q1
Q2
FB
1
8
R1
Control
Logic
SHDN
Driver
RC
CC
1.4MHz
Oscillator
R2
LX
x1
Slope Compensation
Current AMP x 5
+
x20
RS
-
SS
4µA
PWM
Comparator
GND
PIN DESCRIPTIONS
PIN 1: LX
-
Power Switching Connection.
Connect LX to inductor and
output
rectifier.
Keep
the
distance
between
the
components as close to LX as
possible.
PIN 2: GND -
Ground.
PIN 3: FB
Feedback Input. Connect a
resistive voltage-divider from the
output to FB to set the output
voltage.
-
PIN 4: SHDN - Shutdown Input. Drive SHDN
low to turn off the converter. To
automatically start the converter,
connect SHDN to IN. Drive
SHDN with a slew rate of
0.1V/µs or greater. Do not leave
SHDN unconnected. SHDN
draws up to 50µA.
PIN 5: SS
-
Soft-Start Input. Connect a
soft-start capacitor from SS to
GND in order to soft-start the
converter. Leave SS open to
disable the soft-start function.
PIN 6: IN
-
Internal Bias Voltage Input.
Connect IN to the input voltage
source. Bypass IN to GND with
a capacitor sitting as close to IN
as possible.
8
AIC1896
APPLICATION INFORMATION
Inductor Selection
accurate LED current, precision resistors are
A 15µH inductor is recommended for most
preferred (1% recommended). The formula for R1
AIC1896 applications. Although small size and
selection is shown below.
high efficiency are major concerns, the inductor
(1)
R1 = 1.23V/ILED
should have low core losses at 1.4MHz and low
Open-Circuit Protection
DCR (copper wire resistance).
In the cases of output open circuit, when the LEDs
Capacitor Selection
are disconnected from the circuit or the LEDs fail,
The small size of ceramic capacitors makes them
the feedback voltage will be zero. AIC1896 will
ideal for AIC1896 applications. X5R and X7R
then switch to a high duty cycle resulting in a high
types are recommended because they retain their
output voltage, which may cause SW pin voltage
capacitance over wider ranges of voltage and
to exceed its maximum 30V rating. A zener diode
temperature than other types, such as Y5V or
can be used at the output to limit the voltage on
Z5U. A 4.7µF input capacitor and a 1µF output
SW pin (Fig. 20). The zener voltage should be
capacitor
larger than the maximum forward voltage of the
are
sufficient
for
most
AIC1896
applications.
LED string. The current rating of the zener should
be larger than 0.1mA.
Diode Selection
Schottky diodes, with their low forward voltage
Dimming Control
drop and fast reverse recovery, are the ideal
There are three different types of dimming control
choices for AIC1896 applications. The forward
circuits as follows:
voltage drop of a Schottky diode represents the
1. Using a PWM signal
conduction losses in the diode, while the diode
PWM brightness control provides the widest
capacitance (CT or CD) represents the switching
dimming range by pulsing LEDs on and off at full
losses. For diode selection, both forward voltage
and zero current, repectively. The change of
drop
be
average LED current depends on the duty cycle of
considered. Schottky diodes with higher current
the PWM signal. Typically, a 0.1kHz to 10kHz
ratings usually have lower forward voltage drop
PWM signal is used. Two applications of PWM
and larger diode capacitance, which can cause
dimming with AIC 1896 are shown in Fig 21.
significant
1.4MHz
as fig. 21(a), uses PWM signal to drive SHDN
switching frequency of AIC1896. A Schottky diode
pin directly for dimming control. The other, as fig.
rated at 100mA to 200mA is sufficient for most
21(b), employs PWM signal
AIC1896 applications.
resistor to drive FB pin. If the SHDN pin is used,
and
diode
capacitance
switching
losses
at
need
the
to
One,
going through a
the increase of duty cycle results in LED
LED Current Control
brightness enhancement. If the FB pin is used, on
LED current is controlled by feedback resistor (R1
the contrary, the increase of duty cycle will
in Fig. 1). The feedback reference is 1.23V. The
decrease its brightness. In this application, LEDs
LED current is 1.23V/R1. In order to have
9
AIC1896
are dimmed by FB pin and turned off completely by
the FB pin bias current. With a VDC ranging from
SHDN .
0V to 5V, the selection of resistors in Fig. 22
results in dimming control of LED current from
2. Using a DC Voltage
20mA to 0mA, respectively.
For some applications, the preferred method of a
dimming control uses a variable DC voltage to
3. Using a Filtered PWM Signal
adjust LED current. A dimming control using a DC
Filtered PWM signal can be considered as an
voltage is shown as Fig. 22. As DC voltage
adjustable DC voltage. It can be used to replace
increases, the voltage drop over R2 increases and
the variable DC voltage source in dimming control.
the voltage drop over R1 decreases.
The circuit is shown in Fig. 23.
Cautiously selecting R2 and R3 is essential so that
the current from the variable DC source is much
smaller than the LED current and much larger than
L1
10µH
VIN
3.3V to 4.2V
D1
SS0540
SLF6025-100M1R0
C3
C1
4.7µF
ZD1
1µF
BZV55-B24
U1
OFF
AIC1896
23.5V~24.5V
6
IN
LX
1
4
SHDN
FB
3
ON
SS
GND
5
2
R2
IOUT=ILED=20mA
1KΩ
R1
62Ω
C2
0.033µF
Fig. 19 White LED Driver with Open-Circuit Protection
ZD1
AIC1896
IN
LX
IN
LX
R2
PWM
SHDN
FB
R2
GND
Ω
SHDN
ON
1K
SS
ZD1
AIC1896
R1
62
FB
1K
OFF
SS
Ω
GND
R1
R3
30K
C2
C2
0.033µF
0.033µF
62
PWM
(a)
(b)
Fig. 20 Dimming Control Using a PWM Signal
10
AIC1896
ZD1
AIC1896
ZD1
AIC1896
IN
IN
SHDN
R2
SHDN
FB
OFF ON
GND
R3
20mA~0mA
Ω
Ω
C2
0.033µF
0.033µF
R1
Ω
82
3.3K
Ω
Ω
R4 4K
C1
0.1µF
VDC 0V~5V
Fig. 21 Dimming Control Using a DC Voltage
GND
R3
R1
82
Ω
1K
SS
3.3K
C2
FB
OFF ON
Ω
1K
SS
LX
R2
LX
PWM
Fig. 22 Dimming Control Using a Filtered PWM Signal
APPLICATION EXAMPLES
L1
VIN
3V to 4.2V
C1
4.7µF
10µH
D1
SLF6025-100M1R0
SS0504
C3
BZV55-B24
23.5V~24.5V
U1 AIC1896
OFF ON
1µF
ZD1
6
IN
LX
1
4
SHDN
FB
3
GND
SS
5
2
R2
1KΩ
IOUT=ILED=20mA
C2
0.033µF
Fig. 23
R1
62Ω
R3
62Ω
1-Cell Li-Ion Powered Driver for eight White LEDs with Open-Circuit Protection
11
AIC1896
* L1
AIC1896
Vin
C1
33uF
IN
+
D1
LX
SS14
Vout
+
/SHDN FB
* R2
C4
10u/25V
SS GND
C3 100p
R1
12k
C2
0.033uF
C5
0.1uF
Vout
*R2
*L1
5V
9V
36K
10uH
75k
10uH
12V
105k
18V
160k
10uH
22uH
24V
220k
22uH
Fig. 24 Typical Step up Application Circuit
VOUT2
D2
BAT54S
-15V/5mA
C2
L1
VIN
3V to 4.2V
C1
1µF
22uH
1µF/16V
SLF6025-220MR73
C4
4.7µF/6.3V
AIC1896
6
LX
IN
4
SHDN FB
SS GND
OFF ON
5
2
SS0540
D1
1
+15V/5mA
R2
3
135k
R1
12k
C6
VOUT1
C3
1µF/16V
100pF
C5
0.033µF
Fig. 25 1-Cell Li-Ion to
±15V/5mA Dual Output Converter for LCD Bias
VOUT=40V/10mA
D2
BAT54S
C4
0.1uF
C3
0.01u
L1
5VIN
C1
4.7uF
D1
SS054
U1 22uH
IN
SW
SHDN
FB
GND
SS
C5
0.01u
R1
3M
R2
AIC1896
C2
10nF
91k
Fig. 26 High 40V Output Voltage for Electrophoretic Display (EPD) Application
12
AIC1896
Q2
MMBT2907A
D3
C6
C7
1uF
1uF
BAT54WS
C11
1uF
R3
2.2K
Vout3=-7V
D5
7.7V
D2
C8
Vout2=20V
C9
1uF
1uF
L1
Vin
BAT54WS
22uH
C1
4.7uF
D1 SS14
AIC1896
IN
SW
LX
/SHDN FB
SS
GND
R2
12K
Vout1=10V
R1
85K
C3
100pF
C4
10uF/25V
+
C5
0.1uF
C2
0.033uF
Fig. 27 Three output voltage for LCD
13
AIC1896
PHYSICAL DIMENSIONS (unit: mm)
TSOT-23-6
D
S
Y
M
B
O
L
1
E
A
A
e1
E
e
SEE VIEW B
b
WITH PLATING
2
A
c
A
BASE METAL
1
A
SECTION A-A
L1
MILLIMETERS
MIN.
MAX.
A
-
1.00
A1
0
0.10
A2
0.70
0.90
b
0.30
0.50
c
0.08
0.22
D
2.80
3.00
E
2.60
3.00
E1
1.50
1.70
e
0.95 BSC
e1
1.90 BSC
L
0.60
0.30
L1
5
2
.
0
L
TSOT-23-6
θ
0.60 REF
0°
8°
GAUGE PLANE
SEATING PLANE
θ
VIEW B
Note : 1. Refer to JEDEC MO-193AA.
2. Dimension "D" does not include mold flash, protrusions
or gate burrs. Mold flash, protrusion or gate burrs shall not
exceed 6 mil per side.
3. Dimension "E1" does not include inter-lead flash or protrusions.
4. Controlling dimension is millimeter, converted inch
dimensions are not necessarily exact.
14
AIC1896
SOT-23-6
D
1
E
A
A
e1
S
Y
M
B
O
L
E
e
SEE VIEW B
b
WITH PLATING
2
A
c
A
BASE METAL
1
A
SECTION A-A
L1
MILLIMETERS
MIN.
MAX.
A
0.95
1.45
A1
0.05
0.15
A2
0.90
1.30
b
0.30
0.50
c
0.08
0.22
D
2.80
3.00
E
2.60
3.00
E1
1.50
1.70
e
0.95 BSC
e1
L
1.90 BSC
θ
0.60
0.30
L1
5
2
.
0
L
SOT-23-6
0.42 REF
0°
8°
GAUGE PLANE
SEATING PLANE
θ
VIEW B
Note : 1. Refer to JEDEC MO-178AB.
2. Dimension "D" does not include mold flash, protrusions
or gate burrs. Mold flash, protrusion or gate burrs shall not
exceed 10 mil per side.
3. Dimension "E1" does not include inter-lead flash or protrusions.
4. Controlling dimension is millimeter, converted inch
dimensions are not necessarily exact.
Note:
Information provided by AIC is believed to be accurate and reliable. However, we cannot assume responsibility for use of any
circuitry other than circuitry entirely embodied in an AIC product; nor for any infringement of patents or other rights of third
parties that may result from its use. We reserve the right to change the circuitry and specifications without notice.
Life Support Policy: AIC does not authorize any AIC product for use in life support devices and/or systems. Life support devices
or systems are devices or systems which, (I) are intended for surgical implant into the body or (ii) support or sustain life, and
whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably
expected to result in a significant injury to the user.
15
工商网监
湘ICP备2023018690号
