4

LT1121/LT1121-3.3/LT1121-5

1121fe

impedance sources or logic running on supply voltages greater than 5.5V,

the maximum current driven into the shutdown pin must be limited to less

than 20mA.

Note 3: For junction temperatures greater than 110

°C, a minimum load of

may increase by 1%.

Note 4: Operating conditions are limited by maximum junction

temperature. The regulated output voltage specification will not apply for

all possible combinations of input voltage and output current. When

operating at maximum input voltage, the output current range must be

limited. When operating at maximum output current the input voltage

range must be limited.

Note 5: The LT1121 (adjustable version) is tested and specified with the

adjust pin connected to the output pin.

ELECTRICAL CHARACTERISTICS

Note 6: Dropout voltage is the minimum input/output voltage required to

maintain regulation at the specified output current. In dropout the output

current source load. This means that the device is tested while operating in

its dropout region. This is the worst case ground pin current. The ground

pin current will decrease slightly at higher input voltages.

Note 8: Adjust pin bias current flows into the adjust pin.

Note 10: Quiescent current in shutdown is equal to the sum total of the

shutdown pin current (6

μA) and the ground pin current (9μA).

Note 11: Reverse output current is tested with the input pin grounded and

the output pin forced to the rated output voltage. This current flows into

the output pin and out of the ground pin.

LT1121-3.3

Quiescent Current

Guaranteed Dropout Voltage

Dropout Voltage

Quiescent Current

LT1121

Quiescent Current

LT1121-5

Quiescent Current

OUTPUT CURRENT (mA)

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

40

80

120

1121 G27

20

60

140 160

0

100

= TEST POINTS

TEMPERATURE (

°C)

–50

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

0

50

75

1121 G14

–25

25

100

125

TEMPERATURE (

°C)

–50

50

40

30

20

10

0

0

50

75

1121 G11

–25

25

100

125

INPUT VOLTAGE (V)

0

120

100

80

60

40

20

0

8

1121 G03

2

4

6

10

135

79

INPUT VOLTAGE (V)

0

120

100

80

60

40

20

0

8

1121 G02

2

4

6

10

135

79

INPUT VOLTAGE (V)

0

120

100

80

60

40

20

0

8

1121 G04

2

4

6

10

135

79

TYPICAL PERFOR A CE CHARACTERISTICS