computers, PDAs and organizers, handy terminals or any other
portable, battery-powered device.
Figure 1. AS1340 - Typical Application Diagram
L
1
4.7µH
V
IN
= 2.7V to
5.5V
5
LX
V
OUT
= > V
IN
to 50V
VCC
3
L
1
6
V
OUT
LX
3
V
IN
= 2.7V
to 5.5V
C
IN
SWVIN
2
VCC
4
POK
On
Off
1
EN
6
SWOUT
AS1340
R
1
8
FB
7, 9
GND
R
2
C
OUT
V
IN
= 2.7V to
~V
OUT
V
IN
= 2.7V to
5.5V
VCC
3
L
1
6
LX
V
OUT
If not needed the output disconnect switch can be left unconnected which will also increase the efficiency.
Additionally the supply of the chip can be split to allow higher supply voltages for the coil. In this case the output disconnect switch must not be used.
www.ams.com/DC-DC_Step-Up/AS1340
Revision 1.20
1 - 17
AS1340
Datasheet - P i n A s s i g n m e n t s
4 Pin Assignments
Figure 2. Pin Assignments (Top View)
EN 1
VCC
2
8 FB
7 GND
AS1340
SWVIN 3
POK 4
GND 9
6 SWOUT
5 LX
4.1 Pin Descriptions
Table 1. Pin Descriptions
Pin Number
1
2
3
4
5
6
7
8
9
Pin Name
EN
VCC
SWVIN
POK
LX
SWOUT
GND
FB
GND
Description
Active-High Enable Input.
A logic low on this pin shuts down the device and reduces the supply
current to 0.1µA.
Note:
Connect to V
CC
for normal operation.
+2.7V to +5.5V Supply Voltage.
Bypass this pin to GND with a
1µF
capacitor.
Shutdown Disconnect Switch In
Power-OK.
0 = V
OUT
< 90% of V
OUTNOM
.
1 = V
OUT
> 90% of V
OUTNOM
.
Inductor.
The drain of the internal N-channel MOSFET.
Note:
This pin is high impedance in shutdown.
Shutdown Disconnect Switch Out.
Disconnects the input from the output during shutdown.
Ground.
This pin and pin 9 must be connected to GND to ensure normal operation.
Feedback Pin.
Feedback input to the g
m
error amplifier. Connect a resistor divider tap to this pin. The
output voltage can be adjusted from V
IN
to 50V by:
V
OUT
= 1.25V[1 + (R
1
/R
2
)]
Ground.
This pin and pin 7 must be connected to GND to ensure normal operation.
www.ams.com/DC-DC_Step-Up/AS1340
Revision 1.20
2 - 17
AS1340
Datasheet - A b s o l u t e M a x i m u m R a t i n g s
5 Absolute Maximum Ratings
Stresses beyond those listed in
Table 2
may cause permanent damage to the device. These are stress ratings only, and functional operation of
the device at these or any other conditions beyond those indicated in
Electrical Characteristics on page 4
is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
Table 2. Absolute Maximum Ratings
Parameter
Electrical Parameters
VCC, FB, EN to GND
SWVIN, SWOUT to GND
LX to GND
Input Current (latch-up immunity)
Electrostatic Discharge
Electrostatic Discharge HBM
Temperature Ranges and Storage Conditions
Thermal Resistance
JA
Junction Temperature
Storage Temperature Range
-55
36.7
+150
+125
ºC/W
ºC
ºC
The reflow peak soldering temperature (body
temperature) specified is in accordance with
IPC/
JEDEC J-STD-020“Moisture/Reflow Sensitivity
Classification for Non-Hermetic Solid State Surface
Mount Devices”.
The lead finish for Pb-free leaded packages is matte tin
(100% Sn).
Represents a max. floor life time of unlimited
on PCB
1.5
kV
Norm: MIL 883 E method 3015
-100
-0.3
-0.3
7
7
55
100
mA
Norm: JEDEC 78
V
Min
Max
Units
Comments
Package Body Temperature
+260
ºC
Humidity non-condensing
Moisture Sensitive Level
5
1
85
%
www.ams.com/DC-DC_Step-Up/AS1340
Revision 1.20
3 - 17
AS1340
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
6 Electrical Characteristics
V
CC
= EN = 2.7V, T
AMB
= -40 to +85ºC (unless otherwise specified). Typical values are at T
AMB
= +25ºC.
Table 3. Electrical Characteristics
Symbol
T
AMB
V
CC
V
IN
V
OUT
I
CC
Parameter
Operating Temperature Range
Supply Voltage
Inductor Input Voltage Range
Output Voltage Range
Quiescent Supply Current
Enable Supply Current
V
CC
Line Regulation
V
LNR
V
IN
Line Regulation
V
LDR
V
FB
I
FB
DC-DC Switches
V
OUT
max
I
LX(MAX)
R
LX
R
P_ON
I
LX_LEAK
I
P_LEAK
Control Inputs
V
IH
EN Input Threshold
V
IL
I
EN
POK Output
V
OL
POK Output Low Voltage
POK Output High Leakage Current
POK Threshold
Oscillator
f
CLK
Oscillator Frequency
Maximum Duty Cycle
0.85
85
1
90
1.15
95
MHz
%
POK sinking 1mA
POK = 5.5V
Rising edge, referenced to V
OUT(NOM)
87
0.01
100
90
0.2
500
93
V
nA
%
EN Input Bias Current
V
CC
= 5.5V, V
EN
= 0 to 5.5V
-1
2.7V
V
CC
5.5V
0.8 x
V
CC
0.2 x
V
CC
+1
LX Switch Current Limit
LX On-Resistance
Switch On-Resistance
LX Leakage Current
Switch Leakage Current
V
IN
= 5.5V, I
LOAD
= 0mA
V
IN
= 5.5V, I
LOAD
> 20mA
V
CC
= 5.5V, I
LX
= 100mA
V
IN
= 5.5V, PMOS
V
LX
= 50V
V
IN
= 5.5V, PMOS
50
1.41
0.6
0.2
2
0.5
V
A
µA
Load Regulation
Efficiency
Feedback Set Point
Feedback Input Bias Current
V
FB
= 1.3V
V
FB
= 1.3V, V
IN
= 5V
EN = GND
V
OUT
= 18V, I
LOAD
= 1mA, V
IN
= 5.5V,
V
CC
= 2.7 to 5.5V
V
OUT
= 18V, I
LOAD
= 1mA,
V
CC
= 5V, V
IN
= 2.7 to 5.5V
V
OUT
= 18V, V
CC
= V
IN
= 5V, I
LOAD
= 0 to
20mA
L
1
= 10µH, V
IN
= 5.5V, V
OUT
= 20V, I
LOAD
=
100mA
1.225
Condition
Min
-40
2.7
2.7
2.7
30
0.1
0.3
0.25
0.02
88
1.25
5
1.275
100
Typ
Max
+85
5.5
50
50
50
1
Unit
°C
V
V
V
µA
µA
%/V
%/V
%/mA
%
V
nA
V
µA
Note:
All limits are guaranteed. The parameters with min and max values are guaranteed with production tests or SQC (Statistical Quality
Control) methods.
www.ams.com/DC-DC_Step-Up/AS1340
Revision 1.20
4 - 17
AS1340
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
7 Typical Operating Characteristics
Parts used for measurements: 4.7µH (LPS4018-472ML) Inductor, 10µF (GRM32DR71C106KA01) C
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