iDESYN
iD8603
PFM Step-Up DC-DC Converters with Internal Schottky Diode
General Description
Applications
The iD8603 compact, high-efficiency, PFM step-up DC-

Remote Wireless Transmitters
DC converters are available in SOT-89-3,SOT-23-3 and

Personal Medical Devices
SOT-23-5 packages. They feature an extremely low

Digital Still Cameras
quiescent supply current to ensure the highest possible

Single-Cell Battery-Powered Devices
light-load efficiency. Optimized for operation from one to

Low-Power Hand-Held Instruments
two alkaline or nickel-metal-hydride (NiMH) cells, or a

MP3 Players
single Li+ cell, these devices are ideal for applications

Personal Digital Assistants (PDA)
where extremely low quiescent current and ultra-small
size are critical.
Features
The iD8603 includes an internal Schottky diode that

Internal Schottky Diode
reduces PCB board area and total BOM cost. The family

Up to 80% Efficiency (External Schottky Diode)
offers different combinations of fixed or adjustable outputs,

Ultra Low Input Current (9µA at Switch Off)
and shutdown control.

±2.0% Output Voltage Accuracy

Fixed Output Voltage

Up to 200mA Output Current

0.8V to 5.5V Input Voltage Range

Low Start-up Voltage, 0.9V at 1mA

SOT-23-3,SOT-23-5 and SOT-89-3 Package
Ordering Information
iD8603 - □□ □□□ □
Taping
Package
R: Tape and Reel
Marking Information
A22:SOT-89-3 F Type
For marking information, please contact our sales
A30:SOT-23-3
A31:SOT-23-3
representative directly or through distributor around
A50:SOT-23-5
your location.
Output Voltage Voltage Code
1.8 V
18
1.9 V
19
2.1 V
21
2.5 V
25
2.7 V
27
2.8 V
28
3.0 V
30
3.3 V
33
4.0 V
40
Feb.2013
1
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iDESYN
iD8603
Typical Application Circuit
Recommended Operating Conditions
Absolute Maximum Ratings
Supply Voltage VIN
7V
Input Voltage VIN
Power Dissipation, PD @ TA=25°C
Junction Temperature
SOT-89-3
571mW
SOT-23-3 / SOT-23-5
400mW
Ambient Operating Temperature
0.8V to 5.5V
-40°C to 125°C
-40°C to 85°C
Thermal Resistance, ja
SOT-89-3
175°C/W
SOT-23-3 / SOT-23-5
250°C/W
Lead Temperature
Storage Temperature
ESD Susceptibility
HBM (Human Body Mode)
MM (Machine Mode)
Feb.2013
260 °C
-65°C to 150°C
4kV
300V
2
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iD8603
Pin Configurations
(TOP VIEW)
LX
VOUT
LX
GND
3
3
5
4
1
2
1
2
GND
VOUT
GND
LX
SOT-23-3 (A30)
1
2
3
EN VOUT NC
SOT-23-3 (A31)
SOT-23-5
1
2
3
GND VOUT LX
SOT-89-3
Pin Description
SOT-23-3
SOT-23-5
SOT-89-3
Name
3
5
3
LX
1
4
1
GND
--
1
--
EN
Chip Enable (Active High). Note that this pin is high impedance. There
should be a pull low 100k resistor connected to GND when the control
signal is floating.
--
3
--
NC
No Connecting
2
2
2
VOUT
Output Voltage
Feb.2013
Description
Pin for Switching
Ground
3
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iDESYN
iD8603
Electrical Characteristics
All of the below electrical characteristics are tested at room temperature (25℃)
Parameter
Symbol
Min
Typ
Max
Units
ΔVOUT
-2
--
+2
%
Input Voltage
VIN
--
--
5.5
V
Start-up Voltage
VST
IOUT = 1mA, VIN: 0 → 2.0V
--
0.9
1
V
VHO
IOUT = 1mA, VIN: 0 ← 2.0V
0.7
--
--
V
IDD1
To be measured at VIN
continuous switching
--
35
--
--
40
--
--
9
--
--
23
--
--
28
--
120
--
--
160
--
--
Output Voltage Accuracy
Hold-on Voltage
Input Current 1
VOUT ≤ 3.5V
(1)
3.5V＜VOUT ≤ 5.0V (2)
Input Current 2 (1)(2)
Input Current 3
LX Switching Current
IDD2
VOUT ≦ 3.5V
(1)
3.5V＜VOUT ≤ 5.0V (2)
VOUT ≦ 3.5V (1)
3.5V＜VOUT ≤ 5.0V (2)
LX Leakage Current
IIN
ISWITCHING
ILEAKAGE
Maximum Oscillator Frequency
FMAX
Oscillator Duty Cycle
DOSC
Test Conditions
To be measured at VOUT in
switch off condition
To be measured at VIN in
no load (guaranteed by I1
and I2)
VLX = 0.4V
VLX = 6.0V
VENH
EN “Low” Voltage
VENL
EN Input Bias Current
Shut-down Current
IBIAS-EN
ISHDN
µA
mA
--
--
1.0
µA
140
190
240
kHz
VOUT = 1.8V to 2.4V
140
190
320
kHz
On (VLX “L”) side
65
75
85
%
--
80
--
%
0.65
0.8
1.0
V
0.9
--
--
V
--
--
0.4
V
--
--
0.5
µA
--
--
2
µA
LX Switch on
EN “High” Voltage
µA
VOUT = 2.5V to 5.0V
Efficiency
VLX Voltage Limit
µA
Same as IDD1, LX Pin
Oscillation Start
Same as IDD1, LX Pin
Oscillation Stop
Same as IDD1,
VEN = 0 2.0V
Same as IDD1,
VEN = 0V
Notes:
(1) VIN = 1.8V, VSS = 0V, IOUT = 1mA, TA = 25° C.
(2) VIN = 3.0V, VSS = 0V, IOUT = 1mA, TA= 25°C.
Feb.2013
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iD8603
Function Block Diagram
EN/NC
*SOT-89-3
Chip Enable
V LX Limiter
LX
V OUT
Buffer
GND
+
PFM Control
OSC 190kHz
_
V REF
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5
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iD8603
Typical Operating Characteristics (V
OUT
= 1.9V, CIN = 10μ F (Ceramic) , COUT = 47μ F (Tantalum), L = 47μ H
(0.62A), without External Schottky Diode, TA = 25℃)
Start-up Voltage vs. Output Current
1.60
1.05
VOUT = 1.9V, COUT = 47μF, L = 47μH
(without External Schottky Diode)
1.40
1.20
1.00
0.80
Start-up (-40℃)
Start-up (-25℃)
Start-up (0℃)
Start-up (25℃)
Start-up (50℃)
Start-up (85℃)
Start-up (100℃)
Start-up (125℃)
0.60
0.40
0.20
(Resistive Load)
0.00
0.01
90
0.1
1
10
0.75
0.60
0.45
Hold-on (2%) (-40℃)
Hold-on (2%) (-25℃)
Hold-on (2%) (0℃)
Hold-on (2%) (25℃)
Hold-on (2%) (50℃)
Hold-on (2%) (85℃)
Hold-on (2%) (100℃)
Hold-on (2%) (125℃)
0.30
0.15
(Resistive Load)
0.00
100
0.01
0.1
1
10
Output Current (mA)
Efficiency vs. Output Current
Output Voltage vs. Output Current
2
VOUT = 1.9V, COUT = 47μF, L = 47μH
(without External Schottky Diode)
VOUT = 1.9V, COUT = 47μF, L = 47μH
(without External Schottky Diode)
1.9
Output Voltage (V)
70
60
VIN=0.9V
VIN=1.0V
50
VIN=1.2V
1.8
1.7
VIN=0.9V
VIN=1.0V
1.6
VIN=1.2V
VIN=1.5V
VIN=1.5V
40
1.5
0
10
20
30
40
50
60
70
80
0
10
Output Ripple vs. Output Current
1.8
Shutdown Current (μA)
Output Ripple (mV)
40
30
20
VIN=0.9V
VIN=1.0V
VIN=1.2V
0
10
20
30
40
50
60
50
60
70
80
70
VOUT = 1.9V, EN=GND, COUT = 47μF, L = 47μH
(without External Schottky Diode)
1.5
1.2
0.9
0.6
VIN =0.9V
VIN =1V
0.3
VIN =1.2V
0
80
-50
-25
0
25
50
75
100
125
o
Output Current (mA)
Feb.2013
40
VIN =1.5V
VIN=1.5V
0
30
Shutdown Current vs. Temperature
VOUT = 1.9V, COUT = 47μF, L = 47μH
(without External Schottky Diode)
10
20
Output Current (mA)
Output Current (mA)
50
100
Output Current (mA)
80
Efficiency (%)
VOUT = 1.9V, COUT = 47μF, L = 47μH
(without External Schottky Diode)
0.90
Hold-on Voltage (V)
Start-up Voltage (V)
Hold-on Voltage vs. Output Current
Temperature ( C)
6
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iD8603
Low Start-up Voltage at 1mA
Low Start-up Voltage at 10mA
VIN (DC)
(1.00V/Div)
VIN (DC)
(1.00V/Div)
VOUT (DC)
(1.00V/Div)
VLX (DC)
(2.00V/Div)
VOUT (DC)
(1.00V/Div)
VLX (DC)
(2.00V/Div)
IIN (DC)
(200mA/Div)
IIN (DC)
(500mA/Div)
VIN=1.0V, VOUT=1.9V, IOUT=1mA (Resistive Load)
(without External Schottky Diode)
VIN=1.2V, VOUT=1.9V, IOUT=10mA (Resistive Load)
(without External Schottky Diode)
Time (2.00s/Div)
Time (20.0ms/Div)
Steady State Operation
Steady State Operation
VLX (DC)
(1.00V/Div)
VLX (DC)
(1.00V/Div)
VOUT (AC)
(10.0mV/Div)
VOUT (AC)
(10.0mV/Div)
VIN=0.9V, VOUT=1.9V, IOUT=10mA
VIN=0.9V, VOUT=1.9V, IOUT=30mA
Time (4.00μs/Div)
Time (4.00μs/Div)
Steady State Operation
Steady State Operation
VLX (DC)
(1.00V/Div)
VLX (DC)
(1.00V/Div)
VOUT (AC)
(10.0mV/Div)
VOUT (AC)
(10.0mV/Div)
VIN=1.0V, VOUT=1.9V, IOUT=10mA
VIN=1.0V, VOUT=1.9V, IOUT=40mA
Time (4.00μs/Div)
Feb.2013
Time (4.00μs /Div)
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iD8603
Steady State Operation
Steady State Operation
VLX (DC)
(1.00V/Div)
VLX (DC)
(1.00V/Div)
VOUT (AC)
(10.0mV/Div)
VOUT (AC)
(10.0mV/Div)
VIN=1.2V, VOUT=1.9V, IOUT=10mA
VIN=1.2V, VOUT=1.9V, IOUT=60mA
Time (10.0μs /Div)
Time (4.00μs /Div)
Steady State Operation
Steady State Operation
VLX (DC)
(1.00V/Div)
VLX (DC)
(1.00V/Div)
VOUT (AC)
(10.0mV/Div)
VOUT (AC)
(10.0mV/Div)
VIN=1.5V, VOUT=1.9V, IOUT=10mA
VIN=1.5V, VOUT=1.9V, IOUT=40mA
Time (20.0μs /Div)
Feb.2013
Time (4.00μs /Div)
8
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iD8603
Figure 3: Typical Application Circuit for SOT-89-3
Application Information
Capacitor Selection
A 47μF tantalum (SMT) output filter capacitor typically
provides 50mV to 100mV output ripple when stepping up
L1
from 3.0V to 5.0V at 1mA to 200mA. Smaller capacitors
47µH
(Shield Inductor)
(down to 10μF with higher ESR) are acceptable for light
VIN
loads or in applications that can tolerate higher output
ripple.
Values
in
the
10μF
to
47μF
range
+
are
1
GND
2
VOUT
3
LX
VOUT
+
C2
47µF
(Tantalum)
C1
22µF
recommended for the iD8603. The equivalent series
resistance (ESR) of both bypass and filter capacitors
affects efficiency and output ripple. The output voltage
Inductor Selection
ripple is the product of the peak inductor current and the
An inductor value of 47μH performs well in iD8603
output capacitor’s ESR. Use low-ESR capacitors for best
applications. However, the inductance value is not critical,
performance, or connect two or more filter capacitors in
and the iD8603 will work with inductors in the 10μH to
parallel.
100μH range. Smaller inductance values typically offer a
smaller physical size for a given series resistance,
Figure 1: Typical Application Circuit for SOT-23-3
allowing the smallest overall circuit dimensions. However,
due to higher peak inductor currents, the output voltage
ripple also tends to be higher. Circuits using larger
inductance values exhibit higher output current capability
and larger physical dimensions for a given series
resistance. The inductor’s incremental saturation current
rating should be greater than the peak switch-current limit,
which is 240mA for the iD8603. However, it is generally
acceptable to bias the inductor into saturation by as much
as 20%, although this will slightly reduce efficiency. The
inductor’s DC resistance significantly affects efficiency.
Figure 2: Typical Application Circuit for SOT-23-5
Thermal Considerations
For continuous operation, do not exceed the maximum
L1
47µH
(Shield Inductor)
1
EN
2
VOUT
3
NC
LX
+
VOUT
C2
+
operation junction temperature 125℃. The maximum
VIN
5
power dissipation depends on the thermal resistance
C1
22µF
GND
of IC package, PCB layout, the rate of surroundings
airflow and temperature difference between junctions
4
47µF
(Tantalum)
to ambient. The maximum power dissipation can be
calculated by following formula:
Feb.2013
9
PD  MAX  
T 
 TA 
J MAX 
 JA
V1.0
iDESYN
Where TJ
(MAX)
iD8603
is the maximum operation junction
Figure 4: Maximum Power Dissipation
temperature 125℃, TA is the ambient temperature and
Maximum Power Dissipation (W)
the JA is the junction to ambient thermal resistance.
For recommended operating conditions specification of
iD8603 where TJ
(MAX)
is the maximum junction
temperature of the die (125℃) and TA is the maximum
ambient temperature. The junction to ambient thermal
resistance JA is layout dependent. For SOT-89-3
packages, the thermal resistance JA is 175℃/W on
the standard JEDEC 51-7 four-layers thermal test
board. The maximum power dissipation at TA = 25℃
packages.
The
maximum
0.6
0.5
0.4
0.3
0.2
SOT-89-3
0.1
SOT-23-3 / SOT-23-5
0
-25
0
25
50
75
100
125
Ambient Temperature (℃)
PD(MAX) = (125℃ - 25℃) / (175℃/W) = 0.571W
SOT-89-3
0.7
-50
can be calculated by following formula:
for
0.8
power
dissipation depends on operating ambient temperature
for fixed TJ (MAX) and thermal resistance JA. For iD8603
packages, the Figure 4 of de-rating curves allows the
designer
to
see
the
effect
of
rising
ambient
temperature on the maximum power allowed.
Feb.2013
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iD8603
Layout Considerations
Careful PC board layout is important for minimizing ground bounce and noise. Keep the IC’s GND pin and the
ground leads of the input and output capacitors less than 0.2in (5mm) apart using a ground plane. In addition, keep
all connections to VOUT and LX as short as possible.
Figure5. PCB Layout Guide (SOT-23-3)
C1 must be
near iD8603
V IN
LX should be connected
to Inductor by wide and
short trace, keep
sensitive compontents
away from this trace.
C1
L1
LX
GND
5
4
SOT-23-5
1
EN
2
3
VOUT NC
The output capacitor C2
should be connected
directly from the VOUT
Pin to ground .
C2
Figure6. PCB Layout Guide (SOT-23-5)
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iD8603
The output capacitor C2
should be connected
directly from the VOUT
Pin to ground .
C2
iD8603
C1 must be
near iD8603
SOT-89-3
C1
V IN
LX 3
VOUT 2
GND
1
L1
LX should be connected
to Inductor by wide and
short trace, keep
sensitive compontents
away from this trace.
Figure7. PCB Layout Guide (SOT-89-3)
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iD8603
Packaging
SOT-23-3
SYMBOLS
A
A1
A2
b
C
D
E
e
H
L
Θ1
Feb.2013
DIMENSIONS IN MILLIMETERS
MIN
1.00
0.00
0.70
0.35
0.10
2.70
1.40
--2.60
0.370
1°
NOM
1.10
--0.80
0.40
0.15
2.90
1.60
1.90(TYP)
2.80
--5°
MAX
1.30
0.10
0.90
0.50
0.25
3.10
1.80
--3.00
--9°
13
DIMENSIONS IN INCH
MIN
0.039
0.000
0.027
0.013
0.004
0.106
0.055
--0.102
0.015
1°
NOM
0.043
--0.031
0.016
0.006
0.114
0.063
0.075
0.110
--5°
MAX
0.051
0.004
0.035
0.020
0.001
0.122
0.071
--0.118
--9°
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iDESYN
iD8603
SOT-23-5
SYMBOLS
A
A1
A2
b
C
D
E
e
H
L
Θ1
e1
Feb.2013
DIMENSIONS IN MILLIMETERS
MIN
NOM
MAX
1.00
1.10
1.30
0.00
--0.10
0.70
0.80
0.90
0.35
0.40
0.50
0.10
0.15
0.25
2.70
2.90
3.10
1.50
1.60
1.80
--1.90(TYP)
--2.60
2.80
3.00
0.370
----1°
5°
9°
--0.95(TYP)
---
14
DIMENSIONS IN INCH
MIN
NOM
MAX
0.039
0.043
0.051
0.000
--0.004
0.027
0.031
0.035
0.013
0.016
0.020
0.004
0.006
0.001
0.106
0.114
0.122
0.059
0.063
0.071
--0.075
--0.102
0.110
0.118
0.015
----1°
5°
9°
--0.037
---
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iDESYN
iD8603
SOT-89-3
SYMBOLS
A
A1
b
b1
C
D
D1
HE
E
e
H
S
e1
Feb.2013
DIMENSIONS IN MILLIMETERS
MIN
1.40
0.80
0.36
0.41
0.38
4.40
1.40
--2.40
2.90
0.35
0.65
1.40
NOM
1.50
1.040.42
0.47
0.40
4.50
1.60
--2.50
3.00
0.40
0.75
1.50
MAX
1.60
--0.48
0.53
0.43
4.600
1.75
4.25
2.60
3.10
0.45
0.85
1.60
15
DIMENSIONS IN INCH
MIN
0.055
0.031
0.014
0.016
0.014
0.173
0.055
--0.094
0.114
0.014
0.026
0.054
NOM
0.059
0.041
0.016
0.185
0.016
0.177
0.062
--0.098
0.118
0.016
0.030
0.059
MAX
0.063
--0.018
0.020
0.017
0.181
0.069
0.167
0.102
0.122
0.018
0.034
0.063
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iD8603
Footprint
SOT-23-3
Footprint Dimension (mm)
Package
Number of
PIN
P1
P2
A
B
C
D
M
SOT-23-3
3
0.95
1.90
3.60
1.60
1.00
0.80
2.70
Tolerance
±0.10
SOT-23-5
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iD8603
SOT-89-3
Feb.2013
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