LTC1258 Series

5

1258sfb

TYPICAL PERFORMANCE CHARACTERISTICS

LTC1258-2.5 Output Voltage vs

Input Voltage

LTC1258-2.5 Input Current vs

Input Voltage

LTC1258-2.5 PSRR vs Frequency

LTC1258-2.5 0.1Hz to 10Hz Noise

LTC1258-5 Input Current vs Input

Voltage in Dropout

LTC1258-2.5 Input Current vs

Input Voltage in Dropout

INPUT VOLTAGE (V)

2

2.5010

2.5005

2.5000

2.4995

4

68

10

1258 G07

12

14

INPUT VOLTAGE (V)

2

7

6

5

4

4

68

10

1258 G08

12

14

FREQUENCY (Hz)

60

50

40

30

20

10

0

10

1k

10k

1258 G09

100

5μV/DIV

1258 G10

1SEC/DIV

INPUT VOLTAGE (V)

0123456789

10

1258 G11

1400

1200

1000

800

600

400

200

0

INPUT VOLTAGE (V)

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

1258 G12

250

200

150

100

50

0

PIN FUNCTIONS

OUT (Pin 1): Reference Output. The output can source

up to 10mA and sink up to 2mA. It is stable with output

bypass capacitor ranging from 0μF to 1μF.

IN (Pin 2): Positive Supply. Bypassing with a 0.1μF ca-

pacitor is recommended if the output loading changes.

DNC (Pin 3): (LTC1258-2.5/LTC1258-3/LTC1258-4.1/

LTC1258-5) Do Not Connect. Connected internally for post

package trim. This pin must be left unconnected.

FB (Pin 3): (LT1258) Resistor Divider Feedback Pin. Con-

nect a resistor divider from OUT to GND and the center

tap to FB. This pin sets the output potential.

VV

RR

R

+

⎛

⎝⎜

⎞

⎠⎟

2 385

12

2

FB and R2 from FB to GND.

GND (Pin 4): Negative Supply or Ground Connection.

DNC (Pins 5, 6, 7, 8): Do Not Connect. Connected in-

ternally for post package trim. These pins must be left

unconnected.