ams AS1345 18v, high efficiency, dc-dc step-up converter Datasheet

AS1345
18V, High Efficiency, DC-DC Step-Up
Converter
The AS1345 high efficiency DC-DC step-up converter contains
an internal N-channel and an internal P-channel output
isolation switch.
General Description
The device operates from a 2.9V to 5.0V supply and can boost
voltages up to 18V.
A hysteretic control scheme is used to provide the highest
operating efficiency over a wide range of input and output load
conditions. The internal MOSFET switches reduce the external
component count and a high switching frequency allows the
use of tiny surface mount components.
The AS1345 employ a factory set current limit to reduce ripple
and external component size in low output current
applications. With a 500mA current limit the AS1345 is capable
of providing 20mA @ 18V output.
Figure 1:
Available Products
Devices
Peak Coil Current
Output
AS1345A
100mA
adjustable or fixed
AS1345B
200mA
adjustable or fixed
AS1345C
350mA
adjustable or fixed
AS1345D
500mA
adjustable or fixed
For order related information, please refer to “Ordering &
Contact Information” on page 26.
Built-in safety features protect the internal switches and output
components from fault conditions. Additional power-saving
attributes include a very low quiescent current and a true
shutdown mode.
For further understanding in regards to the contents of the
datasheet, please refer to the Reference Guide located at the end
of the document.
ams Datasheet, Confidential: 2013-Nov [1-51]
AS1345 – 1
General Description
Key Benefits & Features
The benefits and features of AS1345, 18V, High Efficiency,
DC-DC Step-Up Converter are listed below:
Figure 2:
Added Value of Using AS1345
Benefits
Features
Supports Lithium primary and re-chargeable
batteries
Input Voltage Range: 2.9V to 5.0V
Supports a variety of end applications
Adjustable Output Voltage Range: 5.0V to 18V
Supports a variety of end applications
Output Current up to 40mA
Allows optimization of circuit depending on output
power demands
Inductor Peak Currents: 100, 200, 350 and 500 mA
Battery life improved
90% Efficiency
Battery supply isolated during shutdown
True Shutdown
Fault tolerant
Short Circuit and Thermal Protection
Small chipscale package
Packages:
• 8-pin (2x2mm) TDFN
• 8-bumps (1.570mm x 0.895mm) WL-CSP with
0.4mm pitch
Applications
The AS1345 is ideal for:
• Small and low current demand LCD panels as well as for
polymer LEDs (OLED)
• Cell phones, PDAs
• Readers
• Mobile terminals
• 3D shutter glasses.
AS1345 – 2
ams Datasheet, Confidential: 2013-Nov [1-51]
General Description
Block Diagram
The functional blocks of this device for reference are
shown below:
Figure 3:
AS1345 Block Diagram
Fixed Output Voltage
VDD = 2.9V to 5.0V
SWIN
SWOUT
10uF
Die
Temperature
Monitor
EN
AS1345
10uF
10uH
D1
LX
Vout = 5.0V to 18V
1uF to 10uF
VDD
FB
ILIM
VDD
+
+
100k
-
POK
POK
-
Driver
&
Control
Logic
-
+
+
+
+
1.125V
1.25V
GND
Adjustable Output Voltage
VDD = 2.9V to 5.0V
SWIN
SWOUT
10uF
Die
Temperature
Monitor
EN
AS1345
10uF
10uH
D1
LX
R2
Vout = 5.0V to 18V
47pF
1uF to 10uF
VDD
FB
ILIM
+
VDD
R3
+
100k
POK
-
+
+
1.25V
ams Datasheet, Confidential: 2013-Nov [1-51]
POK
+
1.125V
+
Driver
&
Control
Logic
GND
AS1345 – 3
Pin Assignments
Pin Assignments
Figure 4:
Pin Assignments (Top View)
Pin A1
indicator
VDD
1
8
GND
EN
2
7
LX
FB
3
6
SWOUT
POK
4
5
SWIN
AS1345
TDFN 8-pin
2x2mm
B1
GND
A1
VDD
B2
LX
A2
EN
B3
SWOUT
A3
FB
B4
SWIN
A4
POK
Figure 5:
Pin Descriptions
Pin Number
TDFN
WLP
1
A1
2
A2
Pin Name
Description
VDD
Supply Voltage. Connect to a 2.9V to 5.0V input supply. Bypass this pin
with a 10μF capacitor.
EN
Enable Pin. Logic controlled shutdown input, 1.8V CMOS compatible;
1 = Normal operation
0 = Shutdown
On request a 100kΩ pull-down resistor can be enabled (factory set).
Feedback Pin. Feedback input to the gm error amplifier.
For an adjustable output voltage connect a resistor divider to this pin.
The output can be adjusted from 5.0V to 18V by:
VOUT = VREF x (1 + R2/R3)
If the fixed output voltage version is used, connect this pin to VOUT.
3
A3
FB
4
A4
POK
POK. Open Drain Output. POK remains low while VOUT is less than 90%
of nominal VOUT. Connect a 100kΩ pull-up resistor from this pin to VDD.
5
B4
SWIN
Shutdown Disconnect Switch In. Input pin of the internal P-channel
MOSFET.
AS1345 – 4
ams Datasheet, Confidential: 2013-Nov [1-51]
Pi n A s s i g n m e n t s
Pin Number
Pin Name
TDFN
Description
WLP
6
B3
SWOUT
7
B2
LX
8
B1
GND
Shutdown Disconnect Switch Out. Output pin of the internal
P-channel MOSFET. Connect to power inductor and decouple to GND
with a 10μF low ESR ceramic capacitor.
When the input disconnect feature is not desired, SWOUT should be
connected to SWIN and VDD.
Inductor. The drain of the internal N-channel MOSFET. Connect to
power inductor and to anode of a schottky diode.
Ground
ams Datasheet, Confidential: 2013-Nov [1-51]
AS1345 – 5
Absolute Maximum Ratings
Stresses beyond those listed in the table below 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 7 is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
Absolute Maximum Ratings
Figure 6:
Absolute Maximum Ratings
Parameter
Min
Max
Unit
Comments
Electrical Parameters
VDD, SWIN, SWOUT to GND
-0.3
7
V
LX, FB to GND
-0.3
20
V
Input Current (latch-up
immunity)
-100
100
mA
1
A
SWIN to SWOUT Current Limit
Norm: JEDEC 78
Electrostatic Discharge
Electrostatic Discharge HBM
±2
kV
Norm: MIL 883 E method 3015
Temperature Ranges and Storage Conditions
Junction temperature
+110
ºC
-55
+125
ºC
for WL-CSP
-55
+150
ºC
for TDFN
Storage temperature range
Package thermal
data
Package body
temperature
WL-CSP
60
TDFN
97
ºC/W
WL-CSP
Norm IPC/JEDEC J-STD-020
+260
ºC
TDFN
Humidity non-condensing
Junction-to-ambient thermal resistance is very
dependent on application and board-layout. In
situations where high maximum power
dissipation exists, special attention must be
paid to thermal dissipation during board
design.
Norm IPC/JEDEC J-STD-020
5
85
%
1
Represents a maximum floor life time of 168h
for TDFN
1
Represents a maximum floor life time of
unlimited for WL-CSP
Moisture sensitive level
Note: 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”.
AS1345 – 6
ams Datasheet, Confidential: 2013-Nov [1-51]
Electrical Characteristics
Electrical Characteristics
All limits are guaranteed. The parameters with Min and Max
values are guaranteed by production tests or SQC (Statistical
Quality Control) methods.
Figure 7:
VDD = VSHDNN = VSWIN = 3.7V, VOUT = 15V, CIN = COUT = 10μF, typical values @ TAMB = +25ºC
(unless otherwise specified)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
TAMB
Operating temperature range
-40
+85
°C
TJ
Operating junction
temperature range
-40
+110
°C
2.9
5.0
V
Input
VDD
VUVLO
Supply voltage range
SWIN connected to VDD
Minimum startup voltage
VDD = SWIN
2.7
V
VDD undervoltage lockout
VDD decreasing (50mV
Hysteresis)
2.7
V
Regulation
VOUT
Adjustable output voltage
range
External FB divider
5
18
V
Feedback voltage tolerance
Tolerance of FB resistors not
included
-3
+3
%
12
Fixed output voltage
Internal FB divider
15
V
17
VFB
Feedback voltage
1.25
V
For adjustable VOUT only
Feedback input current
η
10
1000
nA
Line regulation
VDD = 3.5V to 3.7V
200
mV
Load regulation
VOUT = 15V, ILOAD = 0mA to
5mA
50
mV
Efficiency
L = 22μH, VDD = VSWIN =
3.7V,
VOUT = 15V, ILOAD = 10mA
90
%
ams Datasheet, Confidential: 2013-Nov [1-51]
AS1345 – 7
Electrical Characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Units
Operating Current
Shutdown current @ VDD
1
VSHDNN = 0V
ISHDN
μA
Shutdown current @ SWIN
1
IQ
Quiescent current
No switching, VFB = 1.5V
25
μA
IDDLOAD
Load current
VOUT = 15V, ILOAD = 5mA
25
mA
AS1345A
100
mA
AS1345B
200
mA
AS1345C
350
mA
AS1345D
500
mA
ILIMIT
Coil peak current limit
Switches
RNMOS
NMOS resistance
0.3
Ω
RPMOS
PMOS resistance
0.15
Ω
POK Output
POK output voltage ‘low’
POK sinking 1mA
0.01
POK output voltage ‘high’
POK leakage 1μA
POK output high leakage
current
POK = 3.7V
POK threshold
Rising edge, referenced to
VOUT(NOM)
VDD
0.2
V
VDD
- 0.1
V
1
μA
90
%
Shutdown
VSHDNH
SHDN input ‘high’
1.26
V
2.9V < VDD < 5.0V, no load
VSHDNL
SHDN input ‘low’
ISHDN
SHDN input current
-1
0.55
V
+1
μA
Soft Start
IPRE
Pre-charge current
100
mA
Thermal shutdown
150
°C
Thermal shutdown hysteresis
10
°C
Thermal Shutdown
AS1345 – 8
ams Datasheet, Confidential: 2013-Nov [1-51]
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
Typical Operating
Characteristics
V OUT = 15V
Figure 8:
Efficiency vs. IOUT; VIN = 2.7V, ILIMIT = 100mA
100
90
Efficiency (%)
80
70
60
50
40
30
- 40°C
20
+ 25°C
10
+ 85°C
0
0.1
1
10
100
Output Current (mA)
Figure 9:
Efficiency vs. IOUT; VIN = 2.7V, ILIMIT = 500mA
100
90
Efficiency (%)
80
70
60
50
40
30
- 40°C
20
+ 25°C
10
+ 85°C
0
0.1
1
10
100
Output Current (mA)
ams Datasheet, Confidential: 2013-Nov [1-51]
AS1345 – 9
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
Figure 10:
Efficiency vs. IOUT; VIN = 4.5V, ILIMIT = 100mA
100
90
Efficiency (%)
80
70
60
50
40
30
- 40°C
20
+ 25°C
10
+ 85°C
0
0.1
1
10
100
Output Current (mA)
Figure 11:
Efficiency vs. IOUT; VIN = 4.5V, ILIMIT = 500mA
100
90
Efficiency (%)
80
70
60
50
40
30
- 40°C
20
+ 25°C
10
+ 85°C
0
0.1
1
10
100
Output Current (mA)
AS1345 – 10
ams Datasheet, Confidential: 2013-Nov [1-51]
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
Figure 12:
Efficiency vs. VIN; ILOAD = 5mA, ILIMIT = 100mA
100
90
Efficiency (%)
80
70
60
50
40
30
20
10
0
2.5
2.75
3
3.25
3.5
3.75
4
4.25
4.5
Input Voltage (V)
Figure 13:
Efficiency vs. VIN; ILOAD = 5mA/20mA, ILIMIT = 500mA
100
90
Efficiency (%)
80
70
60
50
40
30
20
Iout = 5mA
10
Iout = 20mA
0
2.5
2.75
3
3.25
3.5
3.75
4
4.25
4.5
Input Voltage (V)
ams Datasheet, Confidential: 2013-Nov [1-51]
AS1345 – 11
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
Figure 14:
VOUT vs. IOUT; VIN = 2.7V, ILIMIT = 100mA
20
19
Output Voltage (V)
18
17
16
15
14
- 40°C
13
+ 25°C
12
+ 85°C
11
10
0
2
4
6
8
10
12
14
16
18
Output Current (mA)
Figure 15:
VOUT vs. IOUT; VIN = 4.5V, ILIMIT = 100mA
20
19
Output Voltage (V)
18
17
16
15
14
13
- 40°C
12
+ 25°C
11
+ 85°C
10
0
2
4
6
8
10
12
14
16
18
20
Output Current (mA)
AS1345 – 12
ams Datasheet, Confidential: 2013-Nov [1-51]
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
Figure 16:
VOUT vs. IOUT; VIN = 4.5V, ILIMIT = 500mA
20
19
Output Voltage (V)
18
17
16
15
14
13
- 40°C
12
+ 25°C
11
+ 85°C
10
0
5
10
15
20
25
30
35
40
Output Current (mA)
ams Datasheet, Confidential: 2013-Nov [1-51]
AS1345 – 13
Detailed Description
The AS1345 is a compact step-up DC-DC converters that
operates from a 2.9V to 5.0V supply. Consuming only 25μA of
Quiescent current. These devices include an internal MOSFET
switch with a low on-resistance. A true shutdown feature
disconnects the battery from the load and reduces the supply
current to 0.05μA (typ). These DC-DC converters are available
with either a fixed output or are adjustable up to 18V. Four
current-limit options are available: 100mA, 200mA, 350mA and
500mA.
Detailed Description
Figure 17:
Typical Application Diagram
10uF
10uH to 22uH
SWIN
VDD = 2.9V to 5.0V
SWOUT
VDD
10uF
100k
ON
POK
EN
LX
AS1345
FB
Vout = 5.0V to 18V
47pF
R2
1uF to 10uF
R3
GND
OFF
Modes of Operation
The AS1345 features an advanced current-limited control
scheme operating in hysteretic mode. An internal P-channel
MOSFET switch connects VDD to SWIN to provide power to the
inductor when the converter is operating. When the converter
is shut down, this switch disconnects the input supply from the
inductor (see Figure 17). To boost the output voltage an
N-channel MOSFET switch turns on and allows current to ramp
up in the inductor. Once this current reaches the current limit,
the switch turns off and the inductor current flows through D1
to supply the output. The switching frequency varies
depending on the load and input voltage and can be up to
10kHz.
AS1345 – 14
ams Datasheet, Confidential: 2013-Nov [1-51]
Detailed Description
Shutdown
Drive EN low to enter shutdown mode. During shutdown the
supply current drops to 0.05μA (typ), the output is
dis-connected from the input, and LX enters a high impedance
state. The capacitance and load at the output set the rate at
which V OUT decays. EN can be pulled as high as 6V regardless
of the input and output voltages.
With a typical step-up converter circuit, the output remains
connected to the input through the inductor and output
rectifier, holding the output voltage to one diode drop below
V DD when the converter is shutdown and allowing the output
to draw power from the input.
The AS1345 features a True-Shutdown mode, disconnecting the
output from the input with an internal P-channel MOSFET
switch when shut down. This eliminates power draw from the
input during shutdown mode.
Start-up and Inrush Limiting
If the ENABLE pin is high, the AS1345 uses a multi-stage start-up
sequence. With increasing supply voltage, first the power-on
circuitry becomes active and some internal blocks are initiated.
If the supply exceeds the under-voltage-lockout threshold
(2.7V typ), the pre-charge-phase is initiated. The capacitor at
the SWOUT pin is charged to V IN, and the capacitor at V OUT is
charged to V IN-VSD. During this phase the current is limited to
100mA typical. After the completion of the pre-charge-phase,
the AS1345 enters into switching mode. Here the specified
current-limit IPEAK is used. The circuit operates at maximum
frequency until the desired V OUT is reached. Then AS1345
switches to normal hysteretic operation mode.
If the load current is too high (>50mA) during the
start-up-phase, the attainment of normal operation mode
might be delayed or not done at all.
Adjustable Output Voltage
The output voltage of the AS1345 is adjustable from 5.0V to 18V
by using a resistor voltage-divider (see Figure 18 and
Figure 19). Select R1 from 10kΩ to 600kΩ and calculate R2 with
the following equation:
V OUT = V REF (1 + R 2/R 3)
(EQ1)
Where: V REF = 1.25V
V OUT can range from 5.0V to 18V
For best accuracy, ensure that the bias current through the
feedback resistors is at least 2μA.
The AS1345 can also be used with a fixed output voltage. When
using one of these parts, connect FB directly to the output
(see Figure 20 and Figure 21).
ams Datasheet, Confidential: 2013-Nov [1-51]
AS1345 – 15
Detailed Description
For improved regulation speed and lower ripple C3 should be
applied. For best ripple performance always the adjustable
variant of the AS1345 together with C3 should be used. Other
measures to reduce the ripple could be to select a low peak
current I PEAK and increase C4 and to decrease the value of L.
Figure 18:
AS1345 with Adjustable Output Voltage, with Output Disconnect
10uF
10uH to 22uH
SWIN
VDD = 2.9V to 5.0V
SWOUT
VDD
10uF
100k
ON
LX
AS1345
POK
EN
FB
Vout = 5.0V to 18V
47pF
R2
1uF to 10uF
R3
GND
OFF
Figure 19:
AS1345 with Adjustable Output Voltage, without Output Disconnect
10uH to 22uH
SWIN
VDD = 2.9V to 5.0V
SWOUT
VDD
10uF
100k
ON
POK
EN
LX
AS1345
FB
GND
Vout = 5.0V to 18V
47pF
R2
1uF to 10uF
R3
OFF
AS1345 – 16
ams Datasheet, Confidential: 2013-Nov [1-51]
Detailed Description
Figure 20:
AS1345 with Fixed Output Voltage, with Output Disconnect
10uF
10uH to 22uH
SWIN
VDD = 2.9V to 5.0V
SWOUT
VDD
10uF
100k
ON
LX
AS1345
POK
EN
FB
Vout = 5.0V to 18V
1uF to 10uF
GND
OFF
Figure 21:
AS1345 with Fixed Output Voltage, without Output Disconnect
10uH to 22uH
SWIN
VDD = 2.9V to 5.0V
SWOUT
VDD
10uF
100k
ON
POK
LX
AS1345
EN
FB
Vout = 5.0V to 18V
1uF to 10uF
GND
OFF
ams Datasheet, Confidential: 2013-Nov [1-51]
AS1345 – 17
Detailed Description
Power OK Operation
If desired the POK functionality can be used. In this case a
resistor R1 (~100k) has to be applied between the POK pin and
VIN, because the POK output is an open drain type. If the POK
functionality is not used the pin should be unconnected.
During shut-down the POK pin is high impedance to save
current. Therefore it shows VIN if connected to VIN with a
resistor or is floating otherwise. During start-up the POK goes
to LOW. During normal operation it is usually HIGH but it goes
to LOW if for some reason VOUT drops below 90% of the
nominal output voltage.
Thermal Shutdown
To prevent the AS1345 from short-term misuse and overload
conditions the chip includes a thermal overload protection. To
block the normal operation mode all switches will be turned
off. The device is in thermal shutdown when the junction
temperature exceeds 150°C typ. To resume the normal
operation the temperature has to drop below 140°C typ. A good
thermal path should be provided to dissipate the heat
generated within the package, especially at higher output
power. To dissipate as much heat as possible from the package
into a copper plane with as much area as possible, it’s
recommended to use multiple vias in the printed circuit board.
Continuing operation in thermal overload conditions may
damage the device, and therefore, is considered a bad practice.
AS1345 – 18
ams Datasheet, Confidential: 2013-Nov [1-51]
Detailed Description
Inductor Selection
For best efficiency, choose an inductor with high frequency core
material, such as ferrite, to reduce core losses. The inductor
should have low DCR (DC resistance) to reduce the I²R losses,
and must be able to handle the peak inductor current without
saturating. A 10μH to 22μH inductor with greater than 500mA
current rating and less than 500mΩ DCR is recommended.
When smaller peak currents are selected, the inductor current
specification can be reduced accordingly.
Figure 22:
Recommended Inductors
Part Number
Value
Current
Resistance
Size (ins)
ELJLA100KF
10μH
600mA
0.71Ω
1210
ELJLA220KF
22μH
420mA
1.9Ω
1210
ELJPA100KF2
10μH
400mA
0.35Ω
1210
ELJPA220KF2
22μH
290mA
0.66Ω
1210
ELJPA100KF
10μH
240mA
0.5Ω
1210
ELJPA150KF
15μH
220mA
0.74Ω
1210
ELJPA220KF
22μH
185mA
1.15Ω
1210
ELJPC100MF3
10μH
140mA
0.58Ω
1008
ELJPC220MF3
22μH
100mA
1.22Ω
1008
LQH32PN100MNO
10μH
750mA
0.38Ω
1210
LQH32PN150MNO
15μH
600mA
0.57Ω
1210
LQH32PN220MNO
22μH
500mA
0.81Ω
1210
LQH3NPN100NGO
10μH
500mA
0.38Ω
1212
LQH3NPN150NGO
15μH
370mA
0.91Ω
1212
LQH3NPN220NGO
22μH
340mA
1.1Ω
1212
LQH2MCN100M52
10μH
200mA
2.27Ω
0806
LQH2MCN150M52
15μH
150mA
3.5Ω
0806
LQH2MCN220M52
22μH
130mA
5.5Ω
0806
ams Datasheet, Confidential: 2013-Nov [1-51]
Supplier
Panasonic
www.panasonic.com
Murata
Manufacturing
Company
www.murata.com
AS1345 – 19
Detailed Description
Capacitor Selection
The convertor requires three capacitors. Ceramic X5R or X7R
types will minimize ESL and ESR while maintaining capacitance
at rated voltage over temperature. The V IN capacitor should be
10μF. The V OUT capacitor should be between 1μF and 10μF. A
larger output capacitor should be used if lower peak to peak
output voltage ripple is desired. A larger output capacitor will
also improve load regulation on V OUT. See table below for a list
of capacitors for input and output capacitor selection.
Figure 23:
Recommended Capacitors
Part Number
Value
Voltage
TC Code
Size (ins)
GRM31CR71E106KA12L
10μF
25V
X7
1206
GRM31CR71C106KAC7L
10μF
16V
X7
1206
GRM31CR71A106KA01L
10μF
10V
X7
1206
GRM21BR70J106KE76L
10μF
6.3V
X7
0805
GRM31CR71E475KA88L
4.7μF
25V
X7
1206
GRM21BR71C475KA73L
4.7μF
16V
X7
0805
GRM188R71E105KA12D
1μF
25V
X7
0603
GRM188R71C105KA12D
1μF
16V
X7
0603
AS1345 – 20
Supplier
Murata
Manufacturing
Company
www.murata.com
ams Datasheet, Confidential: 2013-Nov [1-51]
Detailed Description
Schottky Diode Selection
The selection of the external diode depends on the application.
If I OUT is very low most of the time, and VOUT is high, select a
diode with a low reverse current for best efficiency. For lower
V OUT and higher I OUT, select a diode with a lower V FORWARD and
RFORWARD.
Figure 24:
Recommended Diodes
Part
Number
Reverse
Voltage
Average
Rectified
Current
Forward
Voltage
Reverse
Leakage
Current
Package
Supplier
MBR0540
40V
500mA
460mV @
500mA
1μA @ 20V
SOD123
Fairchild
Semiconductor
www.fairchildsemi.com
B140HW
40V
1000mA
460mV @
500mA
0.35μA @
20V
SOD123
Diodes Inc
www.diodes.com
PMEG2010AEB
20V
1A
200mV @
500mA
320μA @
20V
SOD523
NXP Semiconductors
www.nxp.com
CRS04
40V
1A
450mV @
500mA
40μA @
20V
3-2A1A
(Toshiba)
CRS06
20V
1A
325mV @
500mA
250μA @
20V
3-2A1A
(Toshiba)
ams Datasheet, Confidential: 2013-Nov [1-51]
Toshiba
www.toshiba-compone
nts.com
AS1345 – 21
Detailed Description
PCB Layout
Carefully printed circuit layout is important for minimizing
ground bounce and noise. Keep the GND pin and ground pads
for the input and output capacitors as close together as
possible. Keep the connection to LX as short as possible. Locate
the feedback resistors as close as possible to the FB pin and
keep the feedback traces routed away from noisy areas such as
LX.
EMI and overall performance quality are affected by the PCB
layout. The high speed operation of the AS1345 demands
careful attention to board layout. Stated performance will be
difficult to achieve with careless layout. Figure 25 identifies the
high current paths during an operation cycle involving the
switching of the N-channel and P-channel internal switches.
The current paths between SWIN, VIN, C1, C2, C4, L1, D1 and
GND should be short and wide for lowest intrinsic resistive loss
and lowest stray inductance.
A large ground pin copper area will help to lower the chip
temperature. A multilayer board with a separate ground plane
is ideal, but not absolutely necessary.
Figure 25:
AS1345 - Inductor Current Paths
L1
D1
SWOUT
SWIN
VOUT
LX
AS1345
VDD
VBAT
PDRV
C2
C1
RLOAD
R2
NDRV
FB
FB
ILIM
C3
R3
GND
0V
0V
Inductor Current Path NMOS-ON, D1-OFF
Inductor Current Path NMOS-OFF, D1-ON
Load Current Path NMOS-OFF, D1-OFF
AS1345 – 22
ams Datasheet, Confidential: 2013-Nov [1-51]
Pa c k a g e D r a w i n g s & M a r k i n g s
Package Drawings & Markings
The product is available in a 8-pin (2x2) TDFN and 8-bump
(1.570mm x 0.895mm) WL-CSP package.
Figure 26:
8-bump WL-CSP with 0.4mm Pitch
zz
XXXX
Encoded Date Code
Marking Code
XXXX
zz
Note(s) and/or Footnote(s):
1. ccc Coplanarity.
2. All dimensions in μm.
ams Datasheet, Confidential: 2013-Nov [1-51]
AS1345 – 23
Pack age Drawings & Mark ings
Figure 27:
8-pin (2x2) TDFN Package
zz
XXX
Encoded Date Code
Marking Code
XXX
zz
Note(s) and/or Footnote(s):
1. Dimensions & tolerancing conform to ASME Y14.5M-1994.
2. All dimensions are in millimeters. Angles are in degrees.
3. Coplanarity applies to the exposed heat slug as well as the terminal.
4. Radius on terminal is optional.
5. N is the total number of terminals.
AS1345 – 24
ams Datasheet, Confidential: 2013-Nov [1-51]
Pa c k a g e D r a w i n g s & M a r k i n g s
Figure 28:
Package Dimensions
Symbol
Min
Nom
Max
A
0.51
0.55
0.60
A1
0.00
0.02
0.05
A3
-
-
0.22
L
0.45
0.55
0.65
b
0.15
0.20
0.25
D
2.00 BSC
E
2.00 BSC
e
0.50 BSC
aaa
-
0.15
-
bbb
-
0.10
-
ccc
-
0.10
-
ddd
-
0.05
-
eee
-
0.08
-
N
ams Datasheet, Confidential: 2013-Nov [1-51]
8
AS1345 – 25
Ordering & Contact Information
Ordering & Contact Information
The device is available as the standard products listed in the
table below.
On request, all devices can be factory set to enable a 100kΩ
pull-down resistor for the EN pin.
Figure 29:
Ordering Information
Ordering Code
Marking
ILIMIT
Output
Description
AS1345A-BWLT-AD
BK
100mA
adjustable
AS1345A-BWLT-12
BS
12V
AS1345A-BWLT-15
CA
15V
18V, High
Efficiency
DCDC Step-up
Converter
AS1345A-BWLT-17
CI
17V
AS1345A-BTDT-AD
BI
100mA
adjustable
AS1345B-BTDT-AD
BJ
200mA
adjustable
AS1345C-BTDT-AD
CD
350mA
adjustable
AS1345D-BTDT-AD
CL
500mA
adjustable
AS1345D-BWLT-15
BG
500mA
15V
AS1345D-BWLT-17
BH
500mA
17V
Delivery
Form
Tape & Reel
Package
8-bumps
(1.570x0.895m
m) WL-CSP
8-pin (2x2mm)
TDFN
8-bumps
(1.570x0.895m
m) WL-CSP
Buy our products or get free samples online at:
www.ams.com/ICdirect
Technical Support is available at:
www.ams.com/Technical-Support
For further information and requests, e-mail us at:
[email protected]
For sales offices, distributors and representatives, please visit:
www.ams.com/contact
Headquarters
ams AG
Tobelbaderstrasse 30
8141 Unterpremstaetten
Austria, Europe
Tel: +43 (0) 3136 500 0
Website: www.ams.com
AS1345 – 26
ams Datasheet, Confidential: 2013-Nov [1-51]
RoHS Compliant & ams Green Statement
RoHS Compliant & ams Green
Statement
RoHS: The term RoHS compliant means that ams products fully
comply with current RoHS directives. Our semiconductor
products do not contain any chemicals for all 6 substance
categories, including the requirement that lead not exceed
0.1% by weight in homogeneous materials. Where designed to
be soldered at high temperatures, RoHS compliant products are
suitable for use in specified lead-free processes.
ams Green (RoHS compliant and no Sb/Br): ams Green
defines that in addition to RoHS compliance, our products are
free of Bromine (Br) and Antimony (Sb) based flame retardants
(Br or Sb do not exceed 0.1% by weight in homogeneous
material).
Important Information: The information provided in this
statement represents ams knowledge and belief as of the date
that it is provided. ams bases its knowledge and belief on
information provided by third parties, and makes no
representation or warranty as to the accuracy of such
information. Efforts are underway to better integrate
information from third parties. ams has taken and continues to
take reasonable steps to provide representative and accurate
information but may not have conducted destructive testing or
chemical analysis on incoming materials and chemicals. ams
and ams suppliers consider certain information to be
proprietary, and thus CAS numbers and other limited
information may not be available for release.
ams Datasheet, Confidential: 2013-Nov [1-51]
AS1345 – 27
Copyrights & Disclaimer
Copyrights & Disclaimer
Copyright ams AG, Tobelbader Strasse 30, 8141
Unterpremstaetten, Austria-Europe. Trademarks Registered. All
rights reserved. The material herein may not be reproduced,
adapted, merged, translated, stored, or used without the prior
written consent of the copyright owner.
Devices sold by ams AG are covered by the warranty and patent
indemnification provisions appearing in its Term of Sale. ams
AG makes no warranty, express, statutory, implied, or by
description regarding the information set forth herein. ams AG
reserves the right to change specifications and prices at any
time and without notice. Therefore, prior to designing this
product into a system, it is necessary to check with ams AG for
current information. This product is intended for use in
commercial applications. Applications requiring extended
temperature range, unusual environmental requirements, or
high reliability applications, such as military, medical
life-support or life-sustaining equipment are specifically not
recommended without additional processing by ams AG for
each application. This Product is provided by ams “AS IS” and
any express or implied warranties, including, but not limited to
the implied warranties of merchantability and fitness for a
particular purpose are disclaimed.
ams AG shall not be liable to recipient or any third party for any
damages, including but not limited to personal injury, property
damage, loss of profits, loss of use, interruption of business or
indirect, special, incidental or consequential damages, of any
kind, in connection with or arising out of the furnishing,
performance or use of the technical data herein. No obligation
or liability to recipient or any third party shall arise or flow out
of ams AG rendering of technical or other services.
AS1345 – 28
ams Datasheet, Confidential: 2013-Nov [1-51]
Reference Guide
Reference Guide
ams Datasheet, Confidential: 2013-Nov [1-51]
1
2
2
3
General Description
Key Benefits & Features
Applications
Block Diagram
4
6
7
9
Pin Assignments
Absolute Maximum Ratings
Electrical Characteristics
Typical Operating Characteristics
14
14
15
15
15
18
18
19
20
21
22
Detailed Description
Modes of Operation
Shutdown
Start-up and Inrush Limiting
Adjustable Output Voltage
Power OK Operation
Thermal Shutdown
Inductor Selection
Capacitor Selection
Schottky Diode Selection
PCB Layout
23
26
27
28
Package Drawings & Markings
Ordering & Contact Information
RoHS Compliant & ams Green Statement
Copyrights & Disclaimer
AS1345 – 29