Advanced Power
Electronics Corp.
FEATURES
Input Voltage：3V to 13V
Output Voltage：3.3V to 20V
Duty Ratio：0% to 85% PWM Control
Oscillation Frequency：500KHz.
Enable and Thermal Shutdown Function.
Internal Current Limit.
Built-in N-channel MOSFET
ESOP-8 & Pb-Free Package.
Halogen Free Product
APE1912
STEP-UP PWM DC/DC CONVERTER
DESCRIPTION
The APE1912 is high efficient step-up DC/DC
converter. Large output current is possible having a built in
internal N channel MOSFET, and using an external coil and
diode.
The APE1912 can be operated at switching
frequencies of 500 kHz allowing for easy filtering and low
noise, the size of the external components can be reduced.
Output voltage is programmable with 1.0V of standard
voltage supply internal, and using externally connected
components, output voltage (FB) can be set up at will. The
soft-start time can be programmed by outside capacitor; the
function prevents overshoot at startup. Build inside Current
limit, Thermal Shutdown and enable functions.
TYPICAL APPLICATION
L1
2.2uH
U1
R1
100K
EN
Vcc
FB
C1
10uF
C3
0.1uF
C2
0.47uF
SS
APE1912
C8
0.47 uF
SGND
NC
SW
PGND
C4
220uF
C5
22uF
R4
12K
D1
B540A
Vout 5 V
=
VCC= 3.0 ~ 4.5V
R3
3K
R5
470R
C7
0.1uF
V
OUT
< 8V, V
OUT
= V
FB
x (1+R4/R3) , V
FB
= 1.0V, R3 = 1K
20mΩ < Cout ESR < 80mΩ
Data and specifications subject to change without notice
1
20130222V1.1
Advanced Power
Electronics Corp.
ABSOLUTE MAXIMUM RATINGS
VCC Pin Voltage (V
CC
) ----------------------------------- GND - 0.3V to GND + 14V
Feedback Pin Voltage (V
FB
) ----------------------------- GND - 0.3V to 6V
ON/OFF Pin Voltage (V
EN
) ------------------------------- GND - 0.3V to VCC
Switch Pin Voltage (V
SW
) --------------------------------- GND - 0.3V to 22V
SS Pin Voltage (V
SS
) -------------------------------------- GND - 0.3V to 6V
Power Dissipation (P
D
) ----------------------------------- Internally limited
Storage Temperature Range (T
ST
) -------------------- -40°C to +150°C
Operating Junction Temperature (T
OPJ
) -------------- -20°C to +125°C
Thermal Resistance from Junction to Case(Rth
JC
)
15°C/W
Thermal Resistance from Junction to Ambient(Rth
JA
)
40°C/W
Note. Rth
JA
is measured with the PCB copper area (connect to exposed pad) of approximately 1 in
2
(Multi-layer).
APE1912
ELECTRICAL SPECIFICATIONS
(V
IN
=3.3V, V
OUT
=5V, T
A
=25
o
C, unless otherwise specified)
Parameter
Operating Supply Voltage
Output Voltage Range
Feedback Voltage
Feedback Bias Current
Quiescent Current
Shutdown Supply Current
Oscillation Frequency
Line Regulation
Load Regulation
EN Pin Logic input threshold
voltage
EN Pin Input Current
SS pin Current
Switching Current Limit
Internal MOSFET R
DSON
Efficiency
Maximum Duty Cycle
Minimum Duty Cycle
Thermal Shutdown Temp
V
SH
V
SL
I
SH
I
SL
I
SS
I
LIM-sw
R
DSON
EFFI
DC
MAX
DC
MIN
TSD
V
CC
=5V
V
CC
=3.3V
V
CC
=3V, V
OUT
=5V, I
OUT
=0.5A
V
FB
=0V
V
FB
=1.5V
SYM
V
CC
V
OUT
V
FB
I
FB
I
CCQ
I
SD
F
OSC
I
OUT
=0.1A
I
OUT
=0.1A
V
FB
=1.5V force driver off
V
EN
=0V
SW pin
V
CC
=3~0.8 x Vout
I
OUT
=50m~1A
High (regulator ON)
Low (regulator OFF)
V
EN
=2.5V (ON)
V
EN
=0.3V (OFF)
TEST CONDITION
MIN
3
3.3
0.98
-
-
-
400
-
-
2
-
-
-
-
5
-
-
-
-
-
-
TYP
-
-
1
0.1
4
1
500
1
1
-
-
20
-1
8
6
25
35
90
85
0
145
MAX
13
20
1.02
0.5
6
10
600
-
-
-
0.8
-
-
-
-
-
-
-
-
-
-
o
UNITS
V
V
V
uA
mA
uA
KHz
%
%
V
uA
uA
uA
A
mΩ
%
%
C
2
Advanced Power
Electronics Corp.
PACKAGE & ORDERING INFORMATION
( Top View )
APE1912
APE1912X
Package Type
MP : ESOP-8
EN
V
CC
FB
SS
1
2
3
4
Exposed
pad
8
7
6
5
ESOP-8
( EP is connect to SW)
SGND
NC
SW
PGND
PIN DESCRIPTIONS
PIN SYMBOL
VCC
SW
FB
EN
SS
PGND
SGND
PIN DESCRIPITON
IC Power Supply Pin
Switch pin. Connect external inductor & diode here
Feedback Pin
Shutdown Pin
H : Normal operation
L : Shutdown
Soft-Start Pin.
Power Ground pin
Signal Ground pin.
BLOCK DIAGRAM
Vcc
Phase
Compensation
+
-
Vref=1.0V
FB
Regulator
+
-
Buffer
Driver
SW
PWM
Controller
EN
V
EN
8uA
Thermal
Shutdown
Oscillator
0.06V
SGND
PGND
SS
3
Advanced Power
Electronics Corp.
FUNCTION DESCRIPTION
PWM Control
APE1912
The APE1912 consists of DC/DC converters that employ a pulse-width modulation
(PWM) system. In converters of the APE1912, the pulse width varies in a range from 0 to
85%, according to the load current. The ripple voltage produced by the switching can
easily be removed through a filter because the switching frequency remains constant.
Therefore, these converters provide a low-ripple power over broad ranges of input
voltage and load current.
Setting the Output Voltage
Application circuit item shows the basic application circuit with APE1912 adjustable
output version. The external resistor sets the output voltage according to the following
equation:
V
OUT
= 1.0V x (1+R4/R3)
Table 1 Resistor select for output voltage setting
V
OUT
5V
12V
15V
R3
3K
1K
1.3K
R4
12K
11K
18K
Input Capacitor Selection
The input capacitor reduces the surge current drawn from the input and switching
noise from the device. The input capacitor impedance at the switching frequency shall be
less than input source impedance to prevent high frequency switching current passing to
the input. A low ESR input capacitor sized for maximum RMS current must be used.
The capacitor voltage rating should be at least 1.5 times greater than the input
voltage, and often much higher voltage ratings are needed to satisfy.
FUNCTION DESCRIPTION
Output Capacitor Selection
The output capacitor is required to keep the output voltage ripple small and to
ensure regulation loop stability. The output capacitor must have low impedance at the
switching frequency. A low ESR capacitor sized for maximum RMS current must be
used. The low ESR requirements needed for low output ripple voltage.
The capacitor voltage rating should be at least 1.5 times greater than the input
voltage, and often much higher voltage ratings are needed to satisfy.
4
Advanced Power
Electronics Corp.
FUNCTION DESCRIPTION
Output Capacitor Selection
APE1912
When laying out the PC board, the following suggestions should be taken to ensure
proper operation of the APE1912. These items are also illustrated graphically in below.
1. The power traces, including the Source trace, the Schottky and the C1 trace should
be kept short, direct and wide to allow large current flow.
2. The power ground & R
FB
ground is keep C4 ’ s ground closed and far away signal
ground.
3. The signal ground trance is distant from power ground trance.
4. The exposed pad is connecting to SW trace closely and widely. (Reduce IC
temperature)
5. Do not trace signal line under inductor.
5
Microchip MCU
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