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© 2005 Semtech Corp.

www.semtech.com

POWER MANAGEMENT

SC900A

Applications Information (Cont.)

Output Voltage Code Bits:

A 5-bit linear DAC controls the output voltage of each LDO. The DAC and error-amp gain are scaled so that the LSB

size at the output is 50mV. Output voltage can be set by writing the proper code to the desired LDO register. See Table

A for the bitcodes and their corresponding voltages for LDOs A and B, and Table B for the bitcodes and corresponding

voltages for LDOs C, D and E.

BIT 4

BIT 3

BIT 2

BIT 1

BIT 0

LDO Output Voltage

0

0

0

0

0

1.45V

0

0

0

0

1

1.50V

0

0

0

1

0

1.55V

0

0

0

1

1

1.60V

0

0

1

0

0

1.65V

--

-

-

-

-

--

-

-

-

-

1

1

1

1

0

2.95V

1

1

1

1

1

3.00V

Table A - LDO Output Voltage Control Settings for LDOs A and B

Table B - LDO Output Voltage Control Settings for LDOs C, D and E

BIT 4

BIT 3

BIT 2

BIT 1

BIT 0

LDO Output Voltage

0

0

0

0

0

1.75V

0

0

0

0

1

1.80V

0

0

0

1

0

1.85V

0

0

0

1

1

1.90V

0

0

1

0

0

1.95V

--

-

-

-

-

--

-

-

-

-

1

1

1

1

0

3.25V

1

1

1

1

1

3.30V