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AS1325

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

Capacitor Selection

Low ESR capacitors (X5R or X7R) should be used to minimize the output voltage ripple.

External Diode (5V Output only)

An external Schottky diode must be connected, in parallel with the on-chip synchronous rectifier, from LX to OUT. Use

diodes such as MBR0520L, EP05Q03L, or the generic 1N5817. The diode should be rated for 500mA, since it carries

current during startup and after the synchronous rectifier turns off. The Schottky diode must be connected as close to

the IC as possible. Ordinary rectifier diodes must not be used, since the slow recovery rate will compromise efficiency.

PC Board Layout and Grounding

Well-designed printed circuit-board layout is important for minimizing ground bounce and noise.

!

!

Keep the lead to pin LX as short as possible.

!

To maximize output power and efficiency and minimize output ripple voltage, use a ground plane and solder the

GND pin directly to the ground plane.

Table 6. Recommended Output Capacitor

Part Number

C

TC Code

Rated Voltage

Dimensions (L/W/T)

Manufacturer

C1210C226K9PAK

22µF ±10%

X5R

6.3V

3.2x2.5x1.5mm

Kemet

www.kemet.com

JMK212BJ226MG-T

22µF ±20%

X5R

6.3V

2x1.3x1.3mm

Taiyo Yuden

www.t-yuden.com

Table 7. Recommended Input Capacitor

Part Number

C

TC Code Rated Voltage

Dimensions (L/W/T)

Manufacturer

C1210C226K9PAK

22µF ±10%

X5R

6.3V

3.2x2.5x1.5mm

Kemet

www.kemet.com

GRM31CR70J106KA01L 10µF ±10%

X7R

6.3V

3.2x1.6x1.6mm

Murata

www.murata.com