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AS1344

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

Diode Selection

A Schottky diode must be used to carry the output current into the Cout and load during the NMOS switch-off time.

Note:

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

The MBR0520 is a good choice because of the very low forward voltage and the extremely fast switching. If the output

voltage exceeds 20V the use of the PMEG4005 or the MBR0540 (40V Schottky diodes) is recommended. These

diodes are designed to handle an average forward current of 500mA. In applications with higher loads, the PMEG4010

or the MBRM140 should be used, due to the rated average forward current of 1A.

Table 8. Recommended Diodes

Part Number

Reverse Voltage

Forward Current

Package

Manufacturer

MBR0540

40V

0.5A

SOD123

MCC

www.mccsemi.com

MBR0520

20V

0.5A

SOD123

PMEG4005

40V

0.5A

SOD123

Philips

www.nxp.com

PMEG4010

40V

1A

SOD123

MBRM140

40V

1A

SOD123

ON Semiconductor

www.onsemi.com

Figure 39. Efficiency Comparison of different Diodes;

Figure 40. Efficiency Comparison of different Diodes;

0

10

20

30

40

50

60

70

80

90

0.1

1

10

100

Output Current (mA)

PMEG4010

MBR0540

MBR0520

PMEG4005

0

10

20

30

40

50

60

70

80

90

0.1

1

10

100

Output Current (mA)

PMEG4010

MBR0540

MBR0520

PMEG4005