9

 2006 Semtech Corp.

www.semtech.com

SC1417B

POWER MANAGEMENT

Figure 1 - Constant Brightness LED driver with 12V compliance from 2-cells (constant current output)

Inductor:

Falco P/N SDIP0302-156 (305) 622-9076

or

Coilcraft P/N DT1608C-153 (847) 639-6400

25 mA out (12V compliant)

LBO OUT

GND

LED,3.5V

R2

1M

R6

130k

GND

R5

33k

R4

L1

15uH

C3

2.2nF

C1

22uF,6.3V

C2

4.7uF,16V

VIN

R3

1M

C6

10nF

LED,3.5V

VOUT

D1

SMB5819

U1

SC1417B

8

1

2

3

4

5

6

7

LBO

COMP

FB

EN

GND

LX

IN

LBI

LED,3.5V

Figure 2 - Minimum Capacitance Boost Converter

VIN = 2V to 5V

C2

1uF,16V

R6

130k

LBO OUT

GND

C3

2.2nF

D1

SMB5819

R3

1M

R1

1.00M

GND

L1

15uH

C6

10nF

VOUT = 12V, 75mA

R2

1M

U1

SC1417B

8

1

2

3

4

5

6

7

LBO

COMP

FB

EN

GND

LX

IN

LBI

ENABLE

R4

115k

C1

10uF,6.3V

R5

33k

Note:

(1) Value of C1 depends on proximity of input source voltage and source impedance (use C1 > 47µF if the input

supply is greater than two inches from the SC1417B).

4

R

V

22

.

1

I