3

LT1676

ELECTRICAL CHARACTERISTICS

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Timing

f

Switching Frequency

90

100

110

kHz

q

85

115

kHz

Maximum Switch Duty Cycle

q

85

90

%

Minimum Switch On Time

300

ns

Boost Operation

1.35

V

dV/dt Below Threshold

0.2

V/ns

dV/dt Above Threshold

1.6

V/ns

Sync Function

Minimum Sync Amplitude

q

1.5

2.2

V

Synchronization Range

q

130

250

kHz

SYNC Pin Input R

40

k

Ω

SHDN Pin Function

Shutdown Mode Threshold

0.5

V

q

0.2

0.8

V

Upper Lockout Threshold

Switching Action On

1.260

V

Lower Lockout Threshold

Switching Action Off

1.245

V

Shutdown Pin Current

12

20

µA

2.5

10

µA

TEMPERATURE (

°C)

–50

7.4

7.2

7.0

6.8

6.6

6.4

6.2

6.0

25

75

LT1676 G01

–25

0

50

100

125

Minimum Input Voltage vs

Temperature

SWITCH CURRENT (mA)

0

1.50

1.25

1.00

0.75

0.50

0.25

0

300

500

1676 G02

100

200

400

600

700

125

°C

–55

°C

25

°C

DUTY CYCLE (%)

0

1000

800

600

400

200

0

80

1676 G03

20

10

30

50

70

90

40

60

100

Switch Current Limit vs

Duty Cycle

Switch-On Voltage vs

Switch Current

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

of a device may be impaired.

Note 3: Switch current limit is DC trimmed and tested in production.

Inductor dl/dt rate will cause a somewhat higher current limit in actual

application.

Note 4: Minimum switch on time is production tested with a 50

Ω resistive

load to ground.