Anachip AP1603WA Step-up dc/dc converter Datasheet

AP1603
Step-Up DC/DC Converter
„ Features
„ General Description
-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.
-Space Saving Pb-Free Packages: SOT23-6
The AP1603 is a high efficiency step-up DC/DC
converter for applications using 1 to 2 NiMH battery
cells. Only three external components are required
to deliver a fixed output voltage of 3.3V. The
AP1603 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 150KHz (max.)
switching rate results in smaller passive
components. The space saving SOT23-6 packages
make the AP1603 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.
„ Pin Assignments
„ Pin Descriptions
Name
FB 1
GND 2
Description
1.2V Reference Voltage. Bypass with a 0.1µF
REF
capacitor.
Power Output. OUT provides bootstrap power
OUT
to the IC.
N-Channel and P-Channel Power MOSFET
LX
Drain
GND Ground
Shutdown Input. Drive high (>80% of VOUT) for
operating mode. Drive low (<20% of VOUT) for
SHDN shutdown mode. Connect to OUT for normal
operation.
FB Feedback
6 SHDN
AP1603
5 OUT
74 LX
REF 3
SOT23-6L
„ Ordering Information
AP1603
X
X
Package
Packing
W: SOT23-6L
Blank : Tube
A : Taping
This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of
this product. No rights under any patent accompany the sale of the product.
Rev.1.0 Jun. 3, 2004
1/8
AP1603
Step-Up DC/DC Converter
„ Block Diagram
OUT
+
EN
0.1uF
+
Zero
Crossing
Amplifier
-
SHDN
Minimum
Off-Time
One-Shot Q TRIG
One-Shot
47uF
P
VIN
LX
+
-
Current-Limit
Amplifier
+
TRIG Q
One-Shot
47uF
GND
-
Maximum
On-Time
One-Shot
N
+
+
22uH
F/F
Q
S
R
FB
FB
+
Error
Amplifier
REF
0.1uF
„ Absolute Maximum Ratings
Symbol
VCC
VREF
VSW
IOUT
ISW
TST
TOT
Parameter
Supply Voltage (OUT to GND)
REF to GND
Switch Voltage (LX to GND)
Output Current (OUT)
Switch Current (LX)
Storage Temperature Range
Operation Temperature Range
Anachip Corp.
www.anachip.com.tw
Rating
Unit
-0.3 to 5.5
-0.3 to VOUT+0.3
-0.3 to VOUT+0.3
-0.8 to 0.2
-0.8 to 0.2
-65 to +150
-40 to +80
V
V
V
A
A
o
C
o
C
Rev.1.0 Jun. 3, 2004
2/8
AP1603
Step-Up DC/DC Converter
„ Electrical Characteristics
(VIN=2V, FB=VOUT, RL = ∞, TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.)
Symbol
VIN
Parameter
Minimum Input Voltage
Operating Voltage
Start-Up Voltage
Conditions
Min.
1.1
Typ.
0.9
-
Max.
5.5
Unit
V
V
-
0.9
1.1
V
2
100
-4
150
5.5
-
mV/°C
V
-
80
-
1.196
3.17
4.8
-
1.22
3.3
5
0.05
1.244
3.43
5.2
-
mV/°C
IREF=0 to 30 μA
-
15
80
mV
VIN=1.1V to 3.6V
-
0.08
1.5
mV/V
ILX=100mA
-
0.6
1.0
Ω
0.3
0.35
0.4
A
3
1.0
0.05
16
0.1
90
4
1.2
1
35
1
7
1.4
μA
µA
µA
%
µs
µs
-
0.07
50
nA
0.8
-
0.2
-
VOUT
TA = +25°C
TA = +25°C,
RL = 3kΩ (Note 1)
Start-Up Voltage Tempco
Output Voltage Range
IOUT
Steady-State Output Current
(Note2)
VREF
Reference Voltage
VOUT
Output Voltage
TEMPCO
VREF_LOAD
VREF_LINE
RDS(ON)
ILIM
ILEAK
tON
tOFF
ISHDN
VIL
VIH
Reference Voltage Tempco
Reference Voltage Load
Regulation
Reference Voltage Line
Regulation
Internal NFET, PFET
On-Resistance
LX Switch Current Limit
(NFET)
LX Leakage Current
Operating Current into OUT
Shutdown Current into OUT
Efficiency
LX Switch On-Time
LX Switch Off-Time
FB=VOUT=3.3V
VIN=2.4V, FB=GND,
VOUT=5V
IREF=0
FB=VOUT
FB=GND
VLX=0, 5.5V; VOUT=5.5V
VOUT=3.3V
SHDN =GND
VOUT=3.3V, ILOAD=100mA
SHDN Input Current
V SHDN =0 or VOUT
SHDN Input Voltage
Based on VOUT Voltage
mA
V
V
Note 1: Start-up voltage operation is guaranteed with the addition of a Schottky 1N5819 external diode between the input and output.
Note 2: Steady-state output current indicates that the device maintains output voltage regulation under load.
Anachip Corp.
www.anachip.com.tw
Rev.1.0 Jun. 3, 2004
3/8
AP1603
Step-Up DC/DC Converter
„ Typical Application Circuit
(1) VOUT=5V
1.1V to 5.5V
VIN
22uH
+
47uF
ON
OFF
LX
OUT
SHDN
REF
GND
0.1uF
+
47uF
FB
Fixed Output
( 5V )
(2) VOUT=3.3V
1.1V to 3.6V
VIN
22uH
+
47uF
ON
OFF
LX
SHDN
OUT
REF
GND
0.1uF
+
47uF
Fixed Output
( 3.3V )
FB
(3) VOUT=Adj
1.1V to 5.5V
VIN
22uH
+
47uF
ON
OFF
LX
OUT
SHDN
REF
GND
0.1uF
FB
+
R2
Output
47uF
R1
VOUT= VREF (1+
R2
R1
)
Anachip Corp.
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Rev.1.0 Jun. 3, 2004
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AP1603
Step-Up DC/DC Converter
„ Typical Performance Characteristics
1.23
400
1.22
STEADY STATE
OUTPUT CURRENT
(mA)
1.21
1.2
1.19
320
240
160
80
0
1.18
-40
-20
0
20
40
60
1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3
80
INPUT VOLTAGE (V)
TEMPERATURE (oC)
175
2
with diode
1N5819
1.8
NO LOAD INPUT
CURRENT (uA)
without diode
1.6
1.4
1.2
NO LOAD INPUT CURRENT v.s.
INPUT VOLTAGE
150
125
100
75
1
99
3
2
2.8
79
2.6
59
2.4
39
2.2
18
1.8
9
LOAD CURRENT (mA)
1.6
3
0.89
0
1.2
50
0.8
1
START-UP VOLTAGE (V)
START-UP VOLTAGE v.s.
LOAD CURRENT
1.4
REFERENCE VOLTAGE (V)
STEADY STATE OUTPUT CURRENT
v.s.
INPUT VOLTAGE
REFERENCE VOLTAGE v.s.
TEMPERATURE
INPUT VOLTAGE (V)
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Rev.1.0 Jun. 3, 2004
5/8
AP1603
Step-Up DC/DC Converter
„ Typical Performance Characteristics (Continued)
SHUTDOWN CURRENT
v.s. SUPPLY VOLTAGE
1
0.8
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1
7.
5
20
8
23
8
26
8
29
8
7.
6
17
14
.6
11
.9
87
INPUT VOLTAGE=2.4 (V)
SHUTDOWN THRESHOLD VOLTAGE
v.s. SUPPLY VOLTAGE
SHUTDOWN
THRESHOLD VOLTAGE
(V)
SHUTDOWN CURRENT
(uA)
INPUT VOLTAGE=1.2 (V)
57
91
2.
.9
92.00
91.00
90.00
89.00
88.00
87.00
86.00
85.00
84.00
83.00
82.00
81.00
80.00
7.
6
EFFICIENCY v.s.
INPUT VOLTAGE=2.4V
27
EFFICIENCY (%)
91.00
90.00
89.00
88.00
87.00
86.00
85.00
84.00
83.00
82.00
2.
89
7.
94
17
.8
6
27
.9
37
.9
47
.9
57
.9
67
.9
77
.6
87
.7
97
.6
EFFICIENCY (%)
EFFICIENCY v.s.
INPUT VOLTAGE=1.2V
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
1
2
3
4
1
1.5
2
2.5
3
3.5
4
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
„ Marking Information
Identification code
(See Appendix)
5
4
7
6
XX Y M
1
2
3
Month: A~L
Year: 0-9
Appendix
Part Number
Package
AP1603
SOT23-6
Anachip Corp.
www.anachip.com.tw
Identification
Code
EY
Rev.1.0 Jun. 3, 2004
6/8
AP1603
Step-Up DC/DC Converter
„ Function Descriptions
General Description
AP1603 PFM (pulse frequency modulation)
converter IC series combine a switch mode
converter, power MOSFET, and precision voltage
reference in a single monolithic device. They offer
both extreme low quiescent current, high efficiency,
and very low gate threshold voltage to ensure
start-up with low battery voltage (0.9V typ.).
Designed to maximize battery life in portable
products, and minimize switching losses by only
switching as needed service the load. PFM
converters transfer a discrete amount of energy
per cycle and regulate the output voltage by
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 150KHz. The SW on resistance is typically 1
to 1.5 W to minimize switch losses. When the
output voltage drops, the error comparator enables
150KHz oscillator that turns on the MOSFET
around 7.5us and 2.5ms off time. Turning on the
MOSFET allows inductor current to ramp up,
storing energy in a magnetic field and when
MOSFET turns off that force inductor current
through diode to the output capacitor and load. As
the stored energy is depleted, the current ramp
down until the diode turns off. At this point,
inductor may ring due to residual energy and stray
capacitance. The output capacitor stores charge
when current flowing through the diode is high, and
release it when current is low, 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 converter can
operate in either discontinuous mode or
continuous
conduction
mode.
Continuous
conduction mode means that the inductor current
does not ramp to zero during each cycle.
Inductor Selection
To operate as an efficient energy transfer element,
the inductor must fulfill three requirements. First, the
inductance must be low enough for the inductor to
store adequate energy under the worst case condition
of minimum input voltage and switch ON time. Second,
the inductance must also be high enough so
maximum current rating of AP1603 and inductor are
not exceed at the other worst case condition of
maximum input voltage and ON time. Lastly, the
inductor must have sufficiently low DC resistance so
excessive power is not lost as heat in the windings.
But unfortunately this is inversely related to physical
size. Minimum and Maximum input voltage, output
voltage and output current must be established before
and inductor can be selected.
Capacitor Selection
A poor choice for a output capacitor can result in poor
efficiency and high output ripple. Ordinary aluminum
electrolyzers,
while
inexpensive
may
have
unacceptably poor ESR and ESL. There are low ESR
aluminum capacitors for switch mode DC-DC
converters which work much better than general
propose 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.
Most of the input supply is supplied by the input
bypass capacitor. The capacitor voltage rating should
be at least 1.25 times greater than a maximum input
voltage.
Anachip Corp.
www.anachip.com.tw
Rev.1.0 Jun. 3, 2004
7/8
AP1603
Step-Up DC/DC Converter
„ Package Information
H (Ref.)
Package Type: SOT23-6L
A
G
L
5
4
E
C
1
2
B
3
F
D (Typ.)
Symbol
A
I (Ref.)
6
0.20
L
J (Ref.)
Dimensions In Millimeters
K (Ref.)
Dimensions In Inches
Min.
Nom.
Max.
Min.
Nom.
Max.
2.70
2.90
3.10
0.106
0.114
0.122
B
2.60
2.80
3.00
0.102
0.110
0.118
C
1.40
1.60
1.80
0.055
0.063
0.071
D
0.30
0.43
0.55
0.012
0.017
0.022
E
0
0.05
0.10
0.000
0.002
0.004
F
0o
-
10o
0o
-
10o
G
1.90 Ref.
0.075 Ref.
H
1.20 Ref.
0.047 Ref.
I
0.12 Ref.
0.005 Ref.
J
0.37 Ref.
0.015 Ref.
K
0.60 Ref.
0.024 Ref.
L
0.95 Ref.
0.037 Ref.
Anachip Corp.
www.anachip.com.tw
Rev.1.0 Jun. 3, 2004
8/8
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