LTC4255

3

4255f

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Digital Input Low Voltage

SCL, SDA

q

0.8

V

Digital Input High Voltage

SCL, SDA

q

2.4

V

AD0 to AD4 Pullup Resistors to 5V

30

50

90

k

Ω

AC Characteristics

Current Limit Filter Time

B5 = 0, B4 = 0, Figure 2

q

4.8

6

7.2

ms

B5 = 0, B4 = 1

q

9.6

12

14.4

ms

B5 = 1, B4 = 0

q

19.2

24

28.8

ms

B5 = 1, B4 = 1

q

76.8

96

115.2

ms

Open-Circuit Enable Delay

B7 = 0, B6 = 0

q

50

62

74

ms

After Power_OK

B7 = 0, B6 = 1

q

104

130

156

ms

B7 = 1, B6 = 0

q

213

267

320

ms

B7 = 1, B6 = 1

q

433

541

649

ms

Open-Circuit Filter Time

Figure 3

q

9.6

18

28.8

ms

Turn-On Delay Time

Figure 4

q

9.6

18

28.8

ms

Retry Duty Cycle

B3 = 0

q

0.78

0.83

0.89

%

B3 = 1

q

5.5

6

6.7

%

Clock Frequency

(Note 3)

q

400

kHz

Bus Free Time

Figure 1 (Notes 3, 4)

q

1.3

µs

Start Hold Time

Figure 1 (Notes 3, 4)

q

600

ns

SCL Low Time

Figure 1 (Notes 3, 4)

q

1.3

µs

SCL High Time

Figure 1 (Notes 3, 4)

q

600

ns

Data Hold Time

Figure 1 (Notes 3, 4)

q

150

ns

Data Setup Time

Figure 1 (Notes 3, 4)

q

200

ns

Start Setup Time

Figure 1 (Notes 3, 4)

q

600

ns

Stop Setup Time

Figure 1 (Notes 3, 4)

q

600

ns

Stop to Fault Clear

Figure 1 (Notes 3, 4)

q

300

ns

SCL, SDA Rise Time

Figure 1 (Notes 3, 4)

q

20

300

ns

SCL, SDA Fall Time

Figure 1 (Notes 3, 4)

q

20

150

ns

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

of a device may be impaired.

Note 2: All currents into device pins are positive; all currents out of device

pins are negative. All voltages are referenced to ground unless otherwise

specified.

Note 3: Guaranteed by design, not subject to test.

Note 5: A Zener diode clamps the relay drivers at 18V (RELAY 1-4).