AS1334
Datasheet - Application Information
9 Application Information
Inductor Selection
For the external inductor, a 3.3µH inductor is recommended. Minimum inductor size is dependant on the desired effi-
ciency and output current. Inductors with low core losses and small DCR at 2MHz are recommended.
Table 5. Recommended Inductor
Part Number
L
DCR
Current Rating Dimensions (L/W/T)
Manufacturer
Coilcraft
www.coilcraft.com
LPS4018-222ML_
LPS4018-332ML_
LPS4018-472ML_
2.2µH
3.3µH
4.7µH
0.070Ω
0.080Ω
0.125Ω
2.9A
2.4A
1.9A
3.9x3.9x1.7mm
3.9x3.9x1.7mm
3.9x3.9x1.7mm
Capacitor Selection
A 10µF capacitor is recommended for CIN as well as a 10µF for COUT. Small-sized X5R or X7R ceramic capacitors are
recommended as they retain capacitance over wide ranges of voltages and temperatures.
Input and Output Capacitor Selection
Low ESR input capacitors reduce input switching noise and reduce the peak current drawn from the battery. Also 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.
For input decoupling the ceramic capacitor should be located as close to the device as practical. A 4.7µF input capaci-
tor is sufficient for most applications. Larger values may be used without limitations.
A 2.2µF to 10µF output ceramic capacitor is sufficient for most applications. Larger values up to 22µF may be used to
obtain extremely low output voltage ripple and improve transient response.
Table 6. Recommended Input and Output Capacitor
Part Number
C
TC Code Rated Voltage Dimensions (L/W/T)
Manufacturer
Murata
www.murata.com
GRM188R60J475KE19
GRM219R60J475KE19
GRM21BR61C475KA88
GRM31CR71E475KA88
GRM188R60J106ME47
GRM21BR60J106KE19
GRM21BR61A106KE19
GRM32DR71C106KA01
GRM21BR60J226ME39
GRM32ER71A226KE20
4.7µF
4.7µF
4.7µF
4.7µF
10µF
10µF
10µF
10µF
22µF
22µF
X5R
X5R
X5R
X7R
X5R
X5R
X5R
X7R
X5R
X7R
6.3V
6.3V
16V
25V
6.3V
6.3V
10V
16V
6.3V
10V
0603
0805
0805
1206
0603
0805
0805
1210
0805
1210
EN Pin Control
Drive the EN pin using the system controller to turn the AS1334 ON and OFF. Use a comparator, Schmidt trigger or
logic gate to drive the EN pin. Set EN high (>1.2V) for normal operation and low (<0.5V) for a 0.01µA (typ.) shutdown
mode. Set EN low to turn off the AS1334 during power-up and under voltage conditions when the power supply is less
than the 2.7V minimum operating voltage. The part is out of regulation when the input voltage is less than 2.7V.
www.austriamicrosystems.com
Revision 1.04
13 - 17