AS1302
5V/30mA Adaptive Inductorless Boost Converter
www.austriamicrosystems.com/DC-DC_Step-Up/AS1302 Revision 1.03 1 - 18
Datasheet
1 General Description
The AS1302 is a 30mA inductorless boost converter
using a double H-bridge charge-pump topology with two
external flying capacitors. The AS1302 charge pump
features 1:2 and 2:3 operation modes as well as a 1:1
operation mode where the input is directly connected to
the output.
The AS1302 runs on a 1.2MHz fixed frequency and is
utilized with a low noise regulati on scheme to allow
usage together with sensitive RF circuitry from the same
battery supply. Additionally to increase efficiency the
AS1302 switches to 49kHz at light loads.
Designed to reside in portable and space limited
equipment the 1.2MHz charge pump converts a 2.9V to
5.15V input to regulated 5V output with 3% accuracy.
The shutdown function reduces the supply current to
<1µA and disconnects the load from the output. The
integrated soft-start circuitry prevents high inrush
currents being drawn from the battery during start-up.
The AS1302 includes built-in under-voltage lockout,
short circuit-, and thermal protect i on circu i try.
The AS1302 is available in TDFN (3x3x0.8mm) 10-pin
and an extremely small 1.2x1.2mm WL-CSP 8-bumps
package with 0.4mm pitch.
2 Key Features
! Up to 90% Efficiency
! 2.9V to 5.15V Input Voltage
! Regulated 5V Outpu t
! Automatic Mode Switching
! <1µA Shutdown Current
! Startup with Full Load (within 1ms)
! Up to 30mA Load Current
! Short Circuit Protection
! Output Disconnected During Shutdown
! Soft-Start
! No Inductor Required
! Small External Components Required
(COUT =2.2µF, CFLY =220nF)
! Low Noise Fixed Frequ ency (1.2MHz, 49kHz)
Charge Pump:
- 1:1 Battery Feed Through Mode
- 2:3 Single Phase Mode
- 1:2 Single Phase Mode
! Package Options:
- TDFN (3x3x0.8mm) 10-pin
- WL-CSP 8-bumps with 0.4mm Pitch
3 Applications
The device is ideal for two or three AA cells or a single
Li-Ion battery cell to 5V conversion, mobile phones,
portable instruments, microprocessor based systems
and remote data-acquisition systems.
Figure 1. AS1302 - Typical Application Diagram
VBATT CBAT AS1302
2.2µF
VBATT
EN GND
VOUT
C1+ C1-
C2+ C2-
VOUT = 5V
COUT
2.2µF
On
Off
CFLY1
CFLY2
2.9V to 5.15V
220nF
220nF
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AS1302
Datasheet - Pin A s s i g n m e n t s
4 Pin Assignments
Figure 2. Pin Assignments (Through View)
Pin Descriptions
Table 1. Pin Descriptions
Pin Name Pin Number Description
C1- A1 Connector 1-. Negative terminal of flying cap 1.
GND A2 Ground.
EN A3 Enable. (operating if EN = 1). Set this digital input to logic high for normal
operation. For shutdown, set to logic low.
C1+ B1 Connector 1+. Positive terminal of flying cap 1.
VBATT B3 +2.9V to 5.15V Input Voltage. Byp ass this pin to GND with a ≥2.2µF low
ESR ceramic capacitor.
VOUT C1 +5V Output Voltage. This pin must be bypassed with a ≥2.2µF low ESR
ceramic capacitor.
C2+ C2 Connector 2+. Positive terminal of flying cap 2.
C2- C3 Connector 2-. Negative terminal of flying cap 2.
A3
B3
C3
A1
B1
C1
EN
VBATT
C1-
C1+
VOUT
C2
C2+
A2
GND
C2-
1
GND
AS1302
2
C1-
3
NC
4
C1+
5
VOUT
10 EN
9VBATT
8C2-
7NC
6C2+
GND
TDFN (3x3x0.8mm) 10-pin WL-CSP 8-bumps
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AS1302
Datasheet - Ab so lu te Ma xi mu m R at in gs
5 Absolute Maximum Ratings
Stresses beyo nd 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 othe r conditions beyond those indicated in Section 6 Electri c al
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 Min Max Units Notes
All pins to GND -0.3 +7.0 V
Operating Temperature Range -40 +85 ºC
Storage Temperature Range -65 +125 ºC
ESD 2kV
HBM MIL-Std. 883E 3015.7 methods
500 V CDM JESD22-C101C methods
Package Body Temperature +260 ºC
The reflow peak soldering temp e r at ure
(body temperature) specified is in
accordance with IPC/JEDEC J-STD-
020D “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).
www.austriamicrosystems.com/DC-DC_Step-Up/AS1302 Revision 1.03 4 - 18
AS1302
Datasheet - Ele 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
VBATT = 2.9V to 5.15V, VOUT = 5V, COUT = CBAT = 2.2µ F, CFLY1 = CFLY2 =220nF, TAMB = -40 to +85ºC. Typical values
are at TAMB = +25ºC and VIN = 3.3V, unless otherwise specified.
Table 3. Electrical Characteristi c s
Symbol Parameter Conditions Min Typ Max Units
VBATT(on) Undervoltage Lockout Rising VBATT 2.8 2.9 V
VBATT(off) Undervoltage Lockout Falling VBATT 2.4 2.5 2.8 V
VBATT Battery Supply Voltage 2.9 5.15 V
VOUT Output V oltage Accurracy IOUT = 0mA, 15mA 4.85 5.0 5.15 V
ΔVO/ΔIO11 Load Regulation in 1:1 Mode VBATT = 5.4V, IOUT = 10~30mA 2
mV/mA
ΔVO/ΔIO23 Load Regulation in 2:3 Mode VBATT = 4.3V, IOUT = 10~30mA 3
ΔVO/ΔIO12 Load Regulation in 1:2 Mode VBATT = 3.3V, IOUT = 10~30mA 3
Vtgr11/23
Mode Switching Voltage
1:1 / 2:3 mode, falling VBATT 5.1 V
Vtgr23/12 2:3 / 1:2 mode, falling VBATT 3.6
Mode switching voltage hysteresis 150 mV
IOUT Load Current1
1. The device is tested in a proprietary test mode.
30 mA
Vripple Output Voltage Ripple VBATT = 3.6V, IOUT = 30mA 22 mVPP
VBATT = 3.6V, IOUT = 2mA 40 mVPP
Iinr Inrush Current2
2. The inrush current is limited by the internal soft-start circuitry.
Note: All limits are guaranteed. The parameters with min and max values are guaranteed with production tests or
SQC (Statistical Quality Control) methods.
150 mA
Ishort Short-Circuit Current 150 mA
η12 Efficiency in Switching Mode
1:2 mode, VBATT = 2.9V,
IOUT = 30mA 85 %
η23 2:3 mode, VBATT = 3.8V,
IOUT = 30mA 85 %
IOP12
Operating Quiescent Current
VBATT = 3.4V (1:2 mode without load) 240 300
µA
IOP23 VBATT = 4.5V (2:3 mode without load) 170 230
IOP11 VBATT = 5.3V (1:1 mode without load) 100 150
IOFF Shutdown Current EN = 0V 0.01 1 µA
Input Levels
VIH Input High Level pin EN 1.1 5.5 V
VIL Input Low Level 0.0 0.4 V
Timing
fOSC Oscillator Frequency VBATT = 3.6V, IOUT = 30mA 0.9 1.2 1.5 MHz
VBATT = 3.6V, IOUT = 2mA 40 49 65 kHz
tSTART Startup Time 0.5 1 ms
Thermal Regulation
TOFF Te mp erature Shutdown Temperature rising 145 ºC
Hysteresis 10
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AS1302
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
VBATT = 3.3V, VOUT = 5V, COUT = CBAT = 2.2µF, CFLY1 = CFLY2 =220nF, TAMB = +25ºC, unless otherwise specified.
Figure 3. Efficiency vs. Input Voltage; ILOAD = 1mA Figure 4. Efficiency vs. Input Voltage; ILOAD = 10mA
0
10
20
30
40
50
60
70
80
90
100
2.6 3 3.4 3.8 4.2 4.6 5 5.4
Input Voltage ( V)
Efficiency (%)
1:2
mode 2:3
mode 1:1
mode
0
10
20
30
40
50
60
70
80
90
100
2.6 3 3.4 3.8 4.2 4.6 5 5.4
Input Voltage (V )
Efficiency (%)
1:2
mode 2:3
mode 1:1
mode
Figure 5. Efficiency vs. Input Voltage; ILOAD = 20mA Figure 6. Efficiency vs. Input Voltage; ILOAD = 30mA
0
10
20
30
40
50
60
70
80
90
100
2.6 3 3.4 3.8 4.2 4.6 5 5.4
Input Volt age ( V)
Efficiency (%)
1:2
mode 2:3
mode 1:1
mode
0
10
20
30
40
50
60
70
80
90
100
2.6 3 3.4 3.8 4.2 4.6 5 5.4
Input Volt age ( V)
Efficiency (%)
1:2
mode 2:3
mode 1:1
mode
Figure 7. Quiescent Current vs. Input Voltage Figure 8. Quiescent Current vs. Temperature
50
75
100
125
150
175
200
225
250
275
300
2.4 2.9 3.4 3.9 4.4 4.9 5.4
Input Volt age ( V)
Quiescent Current (µA)
50
75
100
125
150
175
200
225
250
275
300
-45 -30 -15 0 15 30 45 60 75 90
Temperatur e ( ° C)
Quiescent Current (µA)
Vin=3.4V (1:2 Mode)
Vin=4.5V (2:3 Mode)
Vin=5.3V (1:1 Mode)
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AS1302
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
Figure 9. Efficiency vs. Output Current; VBATT = 2.9V Figure 10. Efficiency vs. Output Current; VBATT = 3.3V
0
10
20
30
40
50
60
70
80
90
100
0.1 1 10 100
Output Current (mA)
Efficiency (%)
1.2MHz
49kHz
0
10
20
30
40
50
60
70
80
90
100
0.1 1 10 100
Output Current (mA)
Efficiency (%)
1.2MHz
49kHz
Figure 11. Efficiency vs. Output Current; VBATT = 3.6V Figure 12. Efficiency vs. Output Current; VBATT = 4V
0
10
20
30
40
50
60
70
80
90
100
0.1 1 10 100
Output Current (mA)
Efficiency (%)
1.2MHz
49kHz
0
10
20
30
40
50
60
70
80
90
100
0.1 1 10 100
Output Current (mA)
Efficiency (%)
1.2MHz49kHz
Figure 13. Efficiency vs. Output Current; VBATT = 4.3V Figure 14. Efficiency vs. Output Current; VBATT = 5.4V
0
10
20
30
40
50
60
70
80
90
100
0.1 1 10 100
Output Current (mA)
Ef f iciency (%)
1.2MHz49kHz
0
10
20
30
40
50
60
70
80
90
100
0.1 1 10 100
Output Current (mA)
Ef f iciency (%)
permanent 1:1 Mode
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AS1302
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
Figure 15. Output Voltage vs. Output Current Figure 16. Output Voltage vs. Output Current
4.85
4.9
4.95
5
5.05
5.1
5.15
0.01 0.1 1 10 100
O ut put Current (mA)
Out put Voltage ( V )
Vin = 2.9V
Vin = 3.3V
Vin = 4.3V
1.2MHz
49kHz
4.85
4.9
4.95
5
5.05
5.1
5.15
0.01 0.1 1 10 100
O ut put Current (mA)
Out put Voltage ( V )
Vin = 3.0V
Vin = 3.6V
Vin = 4.0V
1.2MHz
49kHz
Figure 17. Output Voltage vs. Input Voltage Figure 18. Output Voltage vs. Temperature
4.85
4.9
4.95
5
5.05
5.1
5.15
2.9 3.2 3.5 3.8 4.1 4.4 4.7 5 5.3
Input Volt age ( V)
Out put Voltage ( V )
Iout = 4m A
Iout = 10m A
Iout = 20m A
Iout = 30m A
1:2
mode 2:3
mode
1:1
mode
4.85
4.9
4.95
5
5.05
5.1
5.15
-45 -30 -15 0 15 30 45 60 75 90
T emperat ur e ( °C)
Out put Voltage ( V )
Iout = 0.1m A
Iout = 10m A
Iout = 30m A
Figure 19. Startup Time vs. Input Voltage; load=166Ω
0
0.125
0.25
0.375
0.5
0.625
0.75
0.875
1
2.9 3.15 3.4 3.65 3.9 4.15 4.4 4.65 4.9
I n put Voltage ( V)
Startup Time (ms)
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AS1302
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
Figure 20. Turn-ON / Turn-OFF Time @ load = 166ΩFigure 21. Inrush Current; no lo a d
200µs/Div
VOUT
2V/Div1V/Div
EN
50µs/Div
VOUT Iinr
2V/Div 50mA/Div2V/Div
EN
Figure 22. Switching Frequency vs. Input Voltage;
IOUT = 2mA Figure 23. Switching Frequency vs. Input Voltage;
IOUT = 20mA
40
45
50
55
60
65
2.9 3.2 3.5 3.8 4.1 4.4 4.7 5
I n put Voltage ( V)
Switching F requency (kHz)
0.9
1
1.1
1.2
1.3
1.4
1.5
2.9 3.2 3.5 3.8 4.1 4.4 4.7 5
I n put Voltage ( V)
Switching F requency (MHz
)
Figure 24. Switching Frequency vs. Temperature;
IOUT = 2mA Figure 25. Switching Frequency vs. Temperature ;
IOUT = 20mA
40
45
50
55
60
65
-45 -30 -15 0 15 30 45 60 75 90
T emperat ur e ( °C)
S witchin g F r eq uenc y ( k Hz )
0.9
1
1.1
1.2
1.3
1.4
1.5
-45 -30 -15 0 15 30 45 60 75 90
Temperatur e ( ° C)
S witchin g F r eq uenc y ( M Hz
)
www.austriamicrosystems.com/DC-DC_Step-Up/AS1302 Revision 1.03 9 - 18
AS1302
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
Figure 26. Load Transient; Mode = 1:1,
IOUT = 30 to 10 to 30 mA Figure 27. Load Tr ansient; Mode = 2:3,
IOUT = 30 to 10 to 30 mA
500µs/Div
VOUT IOUT
50mV/Div 10mA 30mA
500µs/Div
VOUT IOUT
50mV/Div 10mA 30mA
Figure 28. Load Transient; Mode = 1:2,
IOUT = 30 to 10 to 30 mA Figure 29. Load Transient; Mode = 1:2,
IOUT = 20 to 4 to 20 mA
500µs/Div
VOUT IOUT
50mV/Div 10mA 30mA
500µs/Div
VOUT IOUT
4mA
50mV/Div 20mA
Figure 30. Line Transient Figure 31. Output Ripple
5ms/Div
VIN
3.8V
5mV/Div 4.8V
VOUT
10µs/Div
C2- VOUT
1V/Div 20mV/Div - BW=20MHZ
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AS1302
Datasheet - D et a i l e d De s c r i p t i o n
8 Detailed Description
Functional Description
The AS1302 is a high efficiency and low noise switched capacitor DC-DC converter that is capable of boost operation.
It is equipped with two built-in coupled H-bridge type switch configurations. Based on the value of the output voltage
the system automatically initiates mode-switching to achieve the highest possible efficiency. The regulation of the
output voltage is achieved by a regulation loop, which modulates the current drive capability of the power transistors so
that the amount of char ge transferred from the input to th e output at each clock cycle is controlled and is equal to the
charge needed by the load.
Regulation Loop
The AS1302 operates at a constant frequency. For the regulation loop power transistors, a resistor divider and an error
amplifier are used to keep the output voltage within the allowed limits. The error amplif ier takes the feedback and
reference signals as inputs and generates the error voltage signal. The error voltage controls a dr iver that triggers the
gate voltage of the power transistor which modulates the current drive capability of the power amplifier. The modulated
transistor controls the charge transf erred from the input to the output and therefore th e regulation of the output is
realized. This regulati on concept which is based on adjusting the amount of charge transf erred, delivers the smal l est
voltage ripple possible.
Figure 32. AS1302 - Functional Block Diagram
Light/Heavy Load Monitor
To detetect the output current in the 2:3 and in the 1:2 mode, a current sense is used. The device switches to a lower
switching frequency (49kHz typ), due to a detected light-load condition. With this frequency an excellent light-load
efficiency is achieved and no audible noise is generated. If the load is increasing (typically more than 3mA), the device
operates at 1.2MHz.
+VBATT
CBAT
VOUT
COUT
C1+ C1- C2+ C2-
EN
CFLY1 CFLY2
Double-H Bridge
Topology
Vmode Vctrl
Ref POR
Temp
State Machine
&
Control Logic
Mode
Select
GND
CLK
AS1302
On
Off
Bias
it()td
∫
Soft-
start
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AS1302
Datasheet - D et a i l e d De s c r i p t i o n
Switch Configuration
The AS1302 has nine built-in power swit ches in the shape of two coupled H-bridge topologies. The system features
1:2 and 2:3 operation modes as well as a 1:1 operation where the input is directly connected to t he output.
In 2:3 operation mo de two flying capacitors are placed in series and each capacitor is charged to the half of the input
voltage. In pumping phase the flying capacitors are placed in paralle l. The bottom-plates of the parallel flying
capacitors CFLY1 and CFLY2 are connected to the input voltage so that the voltage at the top-plates of the flying
capacitors is boosted to a voltage equal to VBATT + VBATT/ 2. By connecting the top-plates of the capacitors to the
output, the output voltage in the 2:3 mode can be up to one and a half of VBATT. If the top-plate voltage is higher than
5V, the regulation loop adapts the power transistor’s on-resistance to drop some voltage.
In 1:2 operation both flying capacitors are placed in parallel to the input voltage, and therefore charged to the input
voltage. During pumping phase th e input voltage is connected to the bottom of th e charged flying capacitors. The
voltage at the top-plates of the parallel capacitors is now boosted to 2VBATT. By connecting the top-plates of the
capacitors to the output, the output can be charged to twice the voltage of VBATT. If the top-plate voltage is higher than
5V the regulation loop limits the charge transf er to t he output.
Figure 33. 2:3 Operating Mode
VBATT
+2.9V to 5.15V
SW1
CFLY1 CFLY2
SW3
SW2
SW4
Charging Phase
VOUT
+5V
VBATT
+2.9V to 5.15V
SW1
CFLY1 CFLY2
SW3
SW2
SW4
Pumping Phase
VOUT
+5V
Figure 34. 1:2 Operating Mode
VBATT
+2.9V to 5.15V
SW1
CFLY1 CFLY2
SW3
SW2
SW4
VOUT
+5V
Charging Phase
VBATT
+2.9V to 5.15V
SW1
CFLY1 CFLY2
SW3
SW2
SW4
Pumping Phase
VOUT
+5V
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AS1302
Datasheet - D et a i l e d De s c r i p t i o n
Soft-start
The soft-start circuit prevents the supply from high inrush currents caused by the converter’s power-up sequence.
During the soft-start (0.5ms typ) the device limits the inrush current. The device is capable to power-up at the minimum
specified battery voltage and with the maximum load (ohmic equivalent) applie d to the output.
Undervoltage Lockout, UVLO
The AS1302 is equipped with an undervoltage lockout functionality. If the battery voltage drops below 2.5V (typ) the
device enters the undervol tage locko ut condition. The device remains in this conditio n until the battery voltage is high
enough to enter the soft start sequence. An internal hysteresis of 300mV prevents ringing during startup. If the input
voltage increases to 2.8V (typ) again after such a condit ion the device turns-on aut omatically.
Shutdown Mode
The AS1302 enters low-power shutdown mode when EN is set to logic low. In shutdown the charge-pump action is
halted, the output is completely disconnected from the input and VOUT will drop to 0V.
Note: For a stable operation trigger at least a rising edge on the EN pin to set the internal settings of the device after
VBATT power-up.
Short-Circuit Protection
Short-circuit protection prevents damage to the device if the output is shorted to ground. Whenever the output voltage
is pulled significantly below VBATT, short-circuit protection is triggered and limits the current. As soon as VOUT recovers
the protection is released and the device enters soft-start mode.
Thermal Shutdown
The AS1302 offers thermal shutdown, which prevents damage due to an over-temperature condition. Thermal
shutdown will be initiated if the junction temperature exceeds 145°C. If the temperature drops below this value, the
thermal shutdown will be released automatically and the device resumes operation. A hysteresis prevents the thermal
shutdown from oscillating.
Efficiency Consideration
In the 2:3 operatio n mode the input current of the charge pump is approximately 1.5x the load current. In an ideal
charge pump the efficiency can be calculated by:
The same works for the 1:2 operation mode. The input current of the cha rg e pump is approximately 2x the load
current. The efficiency of a charge pump in 1:2 operation mode can be calculated by:
For typical and high out put power conditions the quiescent current and the switching losses are negligible and (EQ 1)
and (EQ 2) are valid. Hence, with the same input V oltage the 2:3 operation mode will result into a higher efficiency than
the 1:2 operation mode.
(EQ 1)
ηPOUT
PIN
------------- VOUT IOUT
×
VBATT 15IOUT
,×
------------------------------------------- VOUT
15V,BATT
-------------------------
== =
(EQ 2)
ηPOUT
PIN
------------- VOUT IOUT
×
VBATT 2IOUT
×
------------------------------------- VOUT
2VBATT
-------------------
== =
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AS1302
Datasheet - App l i c a t i o n I n f o r m a t i o n
9 Application Information
External Component Selection
The high internal oscillator frequency of 1.2MHz permits the use of small capacitors for both, the flying capacitors and
the output capacitors. For any given load the value of the flying- and output capacitors as well as their ESR are
affecting the output voltage performance.
In general, the capacitor’s ESR is inversely proportional to its physical size. Larger capacitances and higher voltage
ratings tend to reduce ESR . The ESR is a function of the frequency too, so it must be rated at the devices operating
frequency. Another factor affecting capacitor ESR is temperature.
Note: Many capacitors have a huge capacity variation over temperature. This can be compensated by choosing a
capacitor with a better thermal coefficient or by choosing a larger nominal value to ensure proper operation
over temperature.
It is not critical which type of input bypass capacitor CBAT and output filter capacitor COUT is used, but it will affect the
performance of the charge pump. Low ESR capacitors should be used to minimize VOUT ripple. Multi-layer ceramic
capacitors are recommended since they have extremely low ESR and are available in small footprints.
Input Capacitor
A 2.2µF input bypass low ESR capacitor such as tantalum or ceramic is recommended to reduce noise and supply
transients. During startup and mode change it supplies a part of the peak input current drawn by the device.
Output Capacitor
The output capacitor is charged to VOUT during the pumping phase. The ESR of the output capacitor introduces spikes
in the output voltage waveform whenever the charge pump charges COUT. These spikes contribute to the ripple volt-
age of VOUT. Therefore, ceramic or tantalum low ESR capacitors are recommended for COUT to minimize the outpu t
voltage ripple.
Table 4. Recommended Input and Output Capacitors
Part Number CTC Code Rated Voltage Dimensions Manufacturer
GRM188R61C225KE15 2.2µF X5R 16V 0603 Murata
www.murata.com
GRM21BR71E225KA73 2.2µF X7R 25V 0805
GRM188R60J475KE19 4.7µF X5R 6.3V 0603
GRM188R60J106ME47 10µF X5R 6.3V 0603
Figure 35. Load Regulation Comparision with different
Capacitors Figure 36. Output Ripple vs. Output Current
Comparision with different Capacitors
4.85
4.9
4.95
5
5.05
5.1
5.15
0 5 10 15 20 25 30
Load Current (mA)
Out put Voltage ( V )
2.2µF 16V 0603
2.2µF 25V 0805
4.7µF 6.3V 0603
10µF 6.3V 0603 0
20
40
60
80
100
0 5 10 15 20 25 30
Load Cur rent (mA)
Output Ripple (mV)
2.2µF 16V 0603
2.2µF 25V 0805
4.7µF 6.3V 0603
10µF 6.3V 0603
1.2MHz
49kHz
www.austriamicrosystems.com/DC-DC_Step-Up/AS1302 Revision 1.03 14 - 18
AS1302
Datasheet - App l i c a t i o n I n f o r m a t i o n
Flying Capacitor Selection
To ensure the required output current and avoid high peak currents the values of the flying capacitors CFLY1 and CFLY2
are very critical. A 220nF capacitor is sufficient for most applications. Dependent on the operation mode the AS1302
alternately charges and discharges the CFLY1/2 . Whil e the ESR of the output capacitor produces a part of the output
voltage ripple, the ESR of the flying capacitors directly adds to the charge pump’s output source resistance. Therefore
low ESR capacitors, e.g. tantalum or ceramic, are recommended for the flying capacitors as well.
Due to different materials for ceramic capacitors the on the material depending temperature and voltage coefficients
have to be considered. The capacitance of a X7R ceramic capacitor is more stable than a Z5U or Y5V ceramic
capacitor over the whole temperature range from -40°C to +85°C. As an additional effect a Z5U or Y5V ceramic
capacitor will loose about the half of his nominal capacitance when the rated voltage is applied.
It is important to choose the ceramic capacitor according to the minimum available capacitance over the operating
voltage and the bias voltage. This information is stated in the datasheets of the capacitor manufacturer.
Layout Consideration
To achieve the best performance of the AS1302 a careful board layout is necessary to reduce the impact of the high
switching frequency and the high transient currents which are produced by the device. For a proper regulation under all
conditions a true ground plane and short connections to all external capacitors are needed.
Table 5. Recommended Flying Capacitors
Part Number CTC Code Rated Voltage Dimensions Manufacturer
GRM188R71E224KA88 220nF X7R 25V 0603 Murata
www.murata.com
GRM155R61A224KE19 220nF X5R 10V 0402
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AS1302
Datasheet - Pa ck ag e D ra wi ngs an d M ar ki ng s
10 Package Drawings and Markings
The device is available in a TDFN (3x3x0.8mm) 10-pin and WL-CSP 8-bumps p ackage.
Figure 37. TDFN (3x3x0.8mm) 10-pin Package Diagram
Note:
1. Figure 37 is shown for illustration only.
2. N is the total number of terminals.
3. All dimensions are in millimeters, angle is in degrees.
4. Dimensioning and toleran c ing conform to ASME Y14.5M-1994.
Table 6. TDFN (3x3x0.8mm) 10-pin Package Dimensions
Symbol Min Typ Max Symbol Min Typ Max
A 0.70 0.75 0.80 D BSC 3.00
A1 0.00 0.02 0.05 E BSC 3.00
A3 0.20 REF D2 2.20 2.70
L1 0.03 0.15 E2 1.40 1.75
L2 0.13 L 0.30 0.40 0.50
aaa 0.15
θ
0º
bbb 0.10 k 0.20
ccc 0.10 b 0.18 0.25 0.30
ddd 0.05 e 0.50
eee 0.08 N 10
ggg 0.10 ND 5
SEE
DETAIL B
PIN 1 INDEX AREA
(D/2 xE/2)
BTM VIEW
N-1N
b
bb
ddd
D2
D2/2
b
(D/2 xE/2)
2x
2x
TOP VIEW
aaa C
aaa C
E
PIN 1 INDEX AREA
D
ccc C
A
SIDE VIEW
(ND-1) X e
e
0.08 C
A1
A
B
L
C A B
C
E2
E2/2
SEATING
PLANE
A3
K
C
DETAIL B
Datum A or B
Terminal Tip
e
ODD TER MINAL SIDE
www.austriamicrosystems.com/DC-DC_Step-Up/AS1302 Revision 1.03 16 - 18
AS1302
Datasheet - Pa ck ag e D ra wi ngs an d M ar ki ng s
Figure 38. WL-CSP 8-bumps Package Diagram
1210±20.00
1210±20.00
400
40 typ.
200 typ.
600±30
350 typ.
270±10
Notes:
ccc Coplanarity
All dimensions in µm
20µm
CCC
Top through view
Bottom view
Ball side
20
205±20
205±20
www.austriamicrosystems.com/DC-DC_Step-Up/AS1302 Revision 1.03 17 - 18
AS1302
Datasheet - O r d e r i n g I n f o r m a t i o n
11 Ordering Information
The device is available as the standard products shown in Table 7.
Note: All products are RoHS compliant and Pb-free.
Buy our products or get free samples online at ICdirect: http://www.austriamicrosystems.com/ICdirect
For further info rmation and requests, please contact us mailto:sales@austriamicrosystems.com
or find your local distribu tor at http://www.austriamicrosystems.com/distributor
Table 7. Ordering Information
Ordering Code Marking Description Delivery Form Package
AS1302-BWLT ASQ7 5V/30mA Adaptive Inductorles s Boost
Converter Tape and Reel WL-CSP 8-bumps
AS1302-BTDT ASQ7 5V/30mA Adaptive Inductorle s s Boost
Converter Tape and Reel TDFN (3x3x0.8mm)
10-pin
www.austriamicrosystems.com/DC-DC_Step-Up/AS1302 Revision 1.03 18 - 18
AS1302
Datasheet
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