4

LT1308A/LT1308B

1308abfa

LT1308B

3.3V Output Efficiency

LT1308A

5V Output Efficiency

LT1308A

3.3V Output Efficiency

Note 4: Switch current limit guaranteed by design and/or correlation to

static tests. Duty cycle affects current limit due to ramp generator (see

Block Diagram).

Note 5: Bias current flows out of LBI pin.

Note 6: Connect the four GND pins (Pins 4–7) together at the device.

pins (Pins 11, 12) together at the device.

Note 1: Stresses beyond those listed under Absolute Maximum Ratings

may cause permanent damage to the device. Exposure to any Absolute

Maximum Rating condition for extended periods may affect device

reliability and lifetime.

Note 2: The LT1308ACS8, LT1308ACF, LT1308BCS8 and LT1308BCF are

designed, characterized and expected to meet the industrial temperature

limits, but are not tested at – 40

°C and 85°C. I grade devices are

guaranteed over the –40

°C to 85°C operating temperature range.

Note 3: Bias current flows into FB pin.

LOAD CURRENT (mA)

95

90

85

80

75

70

65

60

55

50

1

100

1000

1308A/B G01

10

LOAD CURRENT (mA)

95

90

85

80

75

70

65

60

55

50

1

100

1000

1308A/B G02

10

LOAD CURRENT (mA)

1

95

90

85

80

75

70

65

60

55

50

10

100

1000

1308A/B G03

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Switching Frequency

●

500

600

750

kHz

Maximum Duty Cycle

●

82

90

%

Switch Current Limit

Duty Cyle = 30% (Note 4)

2

3

4.5

A

290

350

mV

330

400

mV

Burst Mode Operation Switch Current Limit

400

mA

(LT1308A)

Shutdown Pin Current

●

2

5

μA

●

20

35

μA

0.01

0.1

μA

LBI Threshold Voltage

196

200

204

mV

●

193

200

207

mV

LBO Output Low

●

0.1

0.25

V

LBO Leakage Current

●

0.01

0.1

μA

LBI Input Bias Current (Note 5)

33

100

nA

Low-Battery Detector Gain

3000

V/V

Switch Leakage Current

●

0.01

10

μA