3

LT1111

1111fd

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Feedback Pin Bias Current

q

70

120

nA

Set Pin Bias Current

q

70

300

nA

Gain Block Output Low

q

0.15

0.4

V

Reference Line Regulation

5V

q

0.02

0.075

%/V

2V

0.20

0.400

%/V

Gain Block Gain

q

1000

6000

V/V

Current Limit

220

400

mA

Current Limit Temperature Coefficient

q

– 0.3

%/

°C

Switch OFF Leakage Current

1

10

µA

Maximum Excursion Below GND

– 400

– 350

mV

ELECTRICAL C

C

HARA TERISTICS

LT1111C

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Quiescent Current

Switch OFF

q

300

450

µA

Oscillator Frequency

q

54

72

95

kH

DC

Duty Cycle: Step-Up Mode

Full Load

q

43

50

59

%

Step-Down Mode

q

24

34

50

%

Switch ON Time: Step-Up Mode

q

5.0

7

9.0

µs

Step-Down Mode

q

3.3

5

7.8

µs

Reference Line Regulation

2V

q

0.2

0.7

%/V

SW Saturation Voltage, Step-Up Mode

q

0.5

0.65

V

SW Saturation Voltage, Step-Down Mode

q

1.1

1.50

V

Note 1: Absolute Maximum Ratings are those values beyond which the life

of a device may be impaired.

Note 2: This specification guarantees that both the high and low trip points

of the comparator fall within the 1.20V to 1.30V range.

Note 3: The output voltage waveform will exhibit a sawtooth shape due to

the comparator hysteresis. The output voltage on the fixed output versions

will always be within the specified range.

Note 4: 100k resistor connected between a 5V source and the A0 pin.