MIC4685

Micrel

September 2002

13

MIC4685

V

OUT

I

R2

V

IN

C1

D1

L1

C5

5.0V

2.0A

3.01k

976

Ω

8V–30V

33

µF, 35V

3A, 40V

39

µH

330

µF, 6.3V

Vishay-Dale

Schottky

Sumida

Vishay-Dale

595D336X0035R2T

B340A

CDRH127-390MC

594D337X06R3D2T

3.3V

2.4A

3.01k

1.78k

8V–26V

33

µF, 35V

3A, 40V

39

µH

330

µF, 6.3V

Vishay-Dale

Schottky

Sumida

Vishay-Dale

595D336X0035R2T

B340A

CDRH127-390MC

594D337X06R3D2T

2.5V

2.35A

3.01k

2.94k

7V–23V

33

µF, 35V

3A, 40V

39

µH

330

µF, 6.3V

Vishay-Dale

Schottky

Sumida

Vishay-Dale

595D336X0035R2T

B340A

CDRH127-390MC

594D337X06R3D2T

1.8V

2.0A

3.01k

6.49k

6V–16V

47

µF, 25V

3A, 40V

39

µH

330

µF, 6.3V

Vishay-Dale

Schottky

Sumida

Vishay-Dale

595D476X0025D2T

B340A

CDRH127-390MC

594D337X06R3D2T

*

Maximum output current at minimum input voltage. See SOA curves for maximum output current vs. input voltage.

Table 2. Recommended Components for Common Ouput Voltages

Recommended Components for a Given Output Voltage (Standard Configuration)

SW

L1

39

µH

IN

FB

GND

EN

D1

B340A

J2

2A

J4

GND

U1 MIC4685BR

C2

0.1

µF

50V

C1

33

µF

35V

J1

(34V transient)

J3

GND

3

BS

1

6

2

5

ON

OFF

C5

330

µF

6.3V

C4*

optional

C7

0.1

µF

50V

C3

0.33

µF

50V

R1

3.01k

R2

6.49k

JP1a

1.8V

R3

2.94k

R4

1.78k

R5

976

Ω

C6**

JP1b

2.5V

JP1c

3.3V

JP1d

5.0V

1

2

3

4

5

6

7

8

*

C4 can be used to provide additional stability

and improved transient response.

** C6 Optional

*** D2 is not used for standard configuration and JP3 is open.

D2***

B340

JP3

4, Tab

Figure 4. Evaluation Board Schematic Diagram