Advanced Power
Electronics Corp.
FEATURES
Very Low Supply Current
Regulated Output Voltage
Wide Range of Output Voltage is Available from
2.2V to 5.0V by 0.1V Steps
Output Voltage Accuracy ±5%
Output Current up to 100mA
Low Ripple and Low Noise
Very Low Start-up Voltage
High Efficiency (Vout = 5V TYP. 87%)
Few External Components
Internal Soft-Start
Low Profile: SOT-23, SOT-89 & SOT-23-5L Pb-Free
Preliminary
APE2903
MICROPOWER VFM STEP-UP DC/DC CONVERTER
DESCRIPTION
The APE2903 is a high efficiency VFM Step-up DC/DC
converter for small, low input voltage or battery powered
systems with ultra low quiescent supply current. The
APE2903 accept a positive input voltage from start-up
voltage to VOUT and convert it to a higher output voltage in
the 2.2 to 5V range.
The APE2903 combine ultra low quiescent supply
current and high efficiency to give maximum battery life. The
high switching frequency and the internally limited peak
inductor current permits the use of small, low cost inductors.
Only three external components are needed an inductor a
diode and an output capacitor.
The APE2903 is suitable to be used in battery powered
equipment where low noise, low ripple and ultra low supply
current are required. The APE2903 is available in very small
package: SOT-23, SOT-89 & SOT-23-5L.
Typical applications are pagers, cameras & video
camera, cellular telephones, wireless telephones, palmtop
computer, battery backup supplies, battery powered
equipment.
TYPICAL APPLICATION
L1
VIN
47uH
Vout
D1
B140
C4
SW
GND
NC OUT
APE2903
NC
C1
100uF
C2
0.1uF
0.1uF
C3
47uF
ORDERING INFORMATION
APE2903X - XX
Package Type
Y5 : SOT-23-5L
N : SOT-23
G : SOT-89
VOUT
22 : 2.2V
25 : 2.5V
26 : 2.6V
27 : 2.7V
:
50 : 5.0V
Data and specifications subject to change without notice
1
20110914pre
Advanced Power
Electronics Corp.
ABSOLUTE MAXIMUM RATINGS
(T
A
= 25
VIN Supply Voltage(V
IN
) ----------------------------------- 5.5 V
SW Voltage(V
SW
) -------------------------------------------- 5.5 V
OUT Voltage(V
OUT
) -----------------------------------------
Power Dissipation(P
D
) -------------------------------------
Storage Temperature Range(T
ST
) ----------------------
5.5 V
( T
J
-T
A
) / R
thja
W
-40°C To 150°C
o
APE2903
C)
Operating Junction Temperature Range(T
OP
) ------- -20°C To + 100°C
Note. Rth
JA
is measured with the PCB copper area of approximately 1 in (Multi-layer) that need connect to GND pin of the APE2903.
2
PACKAGE INFORMATION
Top View
NC
NC
5
4
SOT-89
1
2
3
Tab is
Vout
Top View
Vout
SOT-23-5L
1
2
3
SOT-23
SW
GND
VOUT
Rth
jc
=110 C/W
Rth
ja
=250 C/W
o
o
GND Vout SW
GND
o
SW
Rth
jc
=100 C/W
Rth
ja
=160 C/W
o
o
Rth
jc
=110 C/W
Rth
ja
=250
o
C/W
ELECTRICAL SPECIFICATIONS
( V
IN
=1.8V, I
OUT
=10mA, T
A
=25
o
C, unless otherwise specified)
Parameter
OUTPUT VOLTAGE ACCURACY
START-UP VOLTAGE(V
IN
-V
F
)(Note 1)
SYM
△V
OUT
V
START-UP
V
HOLD
I
SUPPLY
R
LX(DSON
I
LX(leak
F
OSC
D
ON
η
TEST CONDITION
I
OUT
=1mA, V
IN
=rising from 0 to 2V
I
OUT
=1mA, V
IN
=falling from 2 to 0V
No Load
I
LX
=150mA
V
LX
=4V, Forced V
OUT
=3.8V
To be measure on SW pin
Vout=2.2V~3.0V, I
OUT
=50mA
Vout=3.1V~4.0V, I
OUT
=50mA
Vout=4.1V~5.0V, I
OUT
=50mA
MIN
-5
-
0.6
-
-
-
-
-
-
-
-
TYP
-
0.65
-
19
850
-
150
77
82
83
87
MAX
5
0.9
-
-
-
0.5
-
-
-
-
-
UNITS
%
V
V
uA
mΩ
uA
KHz
%
%
%
%
HOLD-ON VOLTAGE
SUPPLY CURRENT
INTERNAL SWITCH R
DSON
INTERNAL LEAKAGE CURRNET
MAXIMUM OSCILLATOR FREQUENCY
OSCILLATOR DUTY ON
EFFICIENCY
Note 1: The minimum input voltage for the IC start-up is strictly a function of the VF catch diode.
PIN DESCRIPTIONS
PIN SYMBOL
SW
GND
OUT
PIN DESCRIPTION
Switch Pin. Connect External Inductor & Diode here.
GND Pin
Output Voltage
2
Advanced Power
Electronics Corp.
BLOCK DIAGRAM
OUT
APE2903
-
V
REF
LIMITER AMP.
VFM
CONTROL
ERROR AMP.
Driver
GND
OPERATION
The APE2903 architecture is built around a VFM CONTROL logic core, switching
frequency is set through a built in oscillator. T
ON
time is fixed (Typ. 5uS) while T
OFF
time is
determined by the error amplifier output, a logic signal coming from the comparison made
by the Error Amplifier Stage between the signal coming from the output voltage divider
network and the internal Band-Gap voltage reference (Vref). T
OFF
reaches a minimum
(Typ. 1.7uS) when heavy load conditions are met (Clock frequency 150KHz). An over
current conditions, through the internal power switch, causes a voltage drop V
LX
=R
DSON
x
I
SW
and the V
LX
limiter block forces the internal switch to be off, so narrowing TON time
and limiting internal power dissipation. In this case the switching frequency may be higher
than the 150KHz set by the internal clock generator.
VFM control ensures very low quiescent current and high conversion efficiency even
with very light loads. Since the Output Voltage pin is also used as the device Supply
Voltage, the versions with higher output voltage present an higher internal supply voltage
that results in lower power switch R
DSON
, slightly greater output power and higher
efficiency. Moreover, bootstrapping allows the input voltage to sag to 0.6V (at I
OUT
=1mA)
once the system is started. If the input voltage exceeds the output voltage, the output will
follow the input, however, the input or output voltage must not be forced above 5.5V.
APPLICATION INFORMATION
INPUT/OUTPUT CAPACITOR SELECTION
The Output Ripple Voltage, as well as the Efficiency, is strictly related to the behavior
of these elements. The output ripple voltage is the product of the peak inductor current
and the output capacitor Equivalent Series Resistance (ESR). Best performances are
obtained with good high frequency characteristics capacitors and low ESR. The best
compromise for the value of the Output Capacitance is 47µF Tantalum Capacitor; Lower
values may cause higher Output Ripple Voltage and lower Efficiency without
compromising the functionality of the device.
An Input Capacitor is required to compensate, if present, the series impedance between
the Supply Voltage Source and the Input Voltage of the Application.
INDUCTOR SELECTION
A 47
µ
H inductor is recommended for most APE2903 applications. However, the
inductance value isnot critical, and the APE2903 will work with inductors in the 33 µ H to
120µH.
+
SW
-
+
3
Advanced Power
Electronics Corp.
APPLICATION INFORMATION
DIODE SELECTION
APE2903
Schottky diodes with higher current ratings usually have lower forward voltage drop,
larger diode capacitance and fast reverse recovery, it is the ideal choices for APE2903
applications. The forward voltage drop of a Schottky diode represents the conduction
losses in the system, while the diode capacitance (C
T
or C
D
) represents the switching
losses. For diode selection, both forward voltage drop and diode capacitance need to be
considered.
PCB LAYOUT GUIDE
When laying out the PC board, the following suggestions should be taken to ensure
proper operation of the APE2903. These items are also illustrated graphically in below.
1. The power traces, including the GND trace, the SW trace and the V
CC
trace should be
kept short, direct and wide to allow large current flow. Put enough multiply-layer pads
when they need to change the trace layer.
2. Do not trace signal line under inductor.
4
Advanced Power
Electronics Corp.
MARKING INFORMATION
SOT-23-5L
APE2903
Part Number : T&3 (see Identification Code)
T&3SS
Date Code : SS
SS:2004,2008,2012…
SS:2003,2007,2011…
SS:2002,2006,2010…
SS:2001,2005,2009…
Part Number
APE2903Y5-2.2V
APE2903Y5-2.5V
APE2903Y5-2.6V
APE2903Y5-2.7V
APE2903Y5-2.8V
APE2903Y5-2.9V
APE2903Y5-3.0V
APE2903Y5-3.1V
APE2903Y5-3.2V
APE2903Y5-3.3V
APE2903Y5-3.4V
APE2903Y5-3.5V
APE2903Y5-3.6V
Identification
Code
To3
TA3
TB3
TC3
TD3
TE3
TH3
TG3
TF3
TI3
TJ3
TK3
TL3
TM3
Part Number
APE2903Y5-3.8V
APE2903Y5-3.9V
APE2903Y5-4.0V
APE2903Y5-4.1V
APE2903Y5-4.2V
APE2903Y5-4.3V
APE2903Y5-4.4V
APE2903Y5-4.5V
APE2903Y5-4.6V
APE2903Y5-4.7V
APE2903Y5-4.8V
APE2903Y5-4.9V
APE2903Y5-5.0V
Identification
Code
TN3
TO3
TP3
TQ3
TR3
TS3
TT3
TU3
TV3
TW3
TX3
TY3
TZ3
SOT-89
Part Number
APE2903Y5-3.7V
2903&
YWWS
Output Voltage : (see
Identification Code)
Date Code (YWWS)
Y : Year
WW : Week
S : Sequence
Part Number
APE2903G-2.2V
APE2903G-2.5V
APE2903G-2.6V
APE2903G-2.7V
APE2903G-2.8V
APE2903G-2.9V
APE2903G-3.0V
APE2903G-3.1V
APE2903G-3.2V
APE2903G-3.3V
APE2903G-3.4V
APE2903G-3.5V
APE2903G-3.6V
Identification
Code
o
A
B
C
D
E
H
G
F
I
J
K
L
M
Part Number
APE2903G-3.8V
APE2903G-3.9V
APE2903G-4.0V
APE2903G-4.1V
APE2903G-4.2V
APE2903G-4.3V
APE2903G-4.4V
APE2903G-4.5V
APE2903G-4.6V
APE2903G-4.7V
APE2903G-4.8V
APE2903G-4.9V
APE2903G-5.0V
Identification
Code
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
SOT-23
APE2903G-3.7V
Part Number : T&3 (see Identification Code)
T&3SS
Date Code : SS
SS:2004,2008,2012…
SS:2003,2007,2011…
SS:2002,2006,2010…
SS:2001,2005,2009…
Part Number
APE2903N-2.2V
APE2903N-2.5V
APE2903N-2.6V
APE2903N-2.7V
APE2903N-2.8V
APE2903N-2.9V
APE2903N-3.0V
APE2903N-3.1V
APE2903N-3.2V
APE2903N-3.3V
APE2903N-3.4V
APE2903N-3.5V
APE2903N-3.6V
APE2903N-3.7V
Identification
Code
To3
TA3
TB3
TC3
TD3
TE3
TH3
TG3
TF3
TI3
TJ3
TK3
TL3
TM3
Part Number
APE2903N-3.8V
APE2903N-3.9V
APE2903N-4.0V
APE2903N-4.1V
APE2903N-4.2V
APE2903N-4.3V
APE2903N-4.4V
APE2903N-4.5V
APE2903N-4.6V
APE2903N-4.7V
APE2903N-4.8V
APE2903N-4.9V
APE2903N-5.0V
Identification
Code
TN3
TO3
TP3
TQ3
TR3
TS3
TT3
TU3
TV3
TW3
TX3
TY3
TZ3
5
Embedded System
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