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AS1330

Datasheet - A p p l i c a t i o n I n f o r m a t i o n

Component Selection

Only three power components are required to complete the design of the boost converter, except the additional two

the use of low value, low profile inductors and tiny external ceramic capacitors.

Inductor Selection

The inductor should have low ESR to reduce the I²R power losses, and must be able to handle the peak inductor

current without saturating. High-frequency ferrite core inductor materials reduce frequency dependent power losses

compared to less expensive powdered iron types, which result in improved converter efficiency.

A 1µH inductor with a >850mA current rating and low DCR is recommended. For applications where radiated noise is

a concern, a toroidal or shielded inductor can be used.

Capacitor Selection

A 4.7µF capacitor is recommended for C1 and for C2. Small-sized ceramic capacitors are recommended. X5R and

X7R ceramic capacitors are recommended as they retain capacitance over wide ranges of voltages and temperatures.

Output Capacitor Selection

they have extremely low ESR and are available in small footprints. Up to 10µF output capacitor is sufficient for most

applications. Larger values up to 22µF may be used to obtain extremely low output voltage ripple and improve tran-

sient response.

An additional phase lead capacitor may be required with output capacitors larger than 10µF to maintain acceptable

phase margin. X5R and X7R dielectric materials are recommended due to their ability to maintain capacitance over

wide voltage and temperature ranges.

Input Capacitor Selection

Low ESR input capacitors reduce input switching noise and reduce the peak current drawn from the battery. Ceramic

capacitors are recommended for input decoupling and should be located as close to the device as is practical. A 4.7µF

input capacitor is sufficient for most applications. Larger values may be used without limitations.

Diode Selection

A Schottky diode should be used to carry the output current for the time it takes the PMOS synchronous rectifier to

≤ 3.0V a it is optional, although using one will

increase device efficiency by 2 to 3%. On one hand the schottky diode reduces the overshoot on the output signal but

on the other hand the output disconnect function is no longer working.

Note:

Do not use ordinary rectifier diodes, since the slow recovery times will compromise efficiency.

Table 4. Recommended External Components

Name

Part Number

Value

Rating

Type

Size

Manufacturer

C1, C2

GRM219R60J106KE19

10µF

6.3V

X5R

0805

Murata

www.murata.com

GRM188R60J475KE19

4.7µF

6.3V

X5R

0603

L1

LQH32PN1R0NN0

1µH

2.05A

45m

Ω

3.2x2.5x1.55mm

LQH32PNR47NN0

470nH

2.55A

30m

Ω

3.2x2.5x1.55mm

EPL2010-102ML

1µH

1.35A

99m

Ω

2.0x2.0x1.0mm Coilcraft

www.coilcraft.com

EPL2010-821ML

820nH

1.6A

68m

Ω

2.0x2.0x1.0mm

EPL2010-471ML

470nH

2.2A

40m

Ω

2.0x2.0x1.0mm