Octal SMBus-to-Parallel I/O Expanders

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3

TIMING CHARACTERISTICS

Note 1: Specifications from 0°C to -40°C are guaranteed by design, not production tested.

Note 2: For supply current, SMBus logic inputs driven to 0 or V+.

Note 3: Data hold and set-up times measured from falling edge of 9th clock.

Note 4: Must be driven to GND, V+, or floating. See SMBus Addressing section.

Note 5: The SMBus logic block is a static design and will work with clock frequencies down to DC. While slow operation is possible,

it violates the 10kHz minimum clock frequency and SMBus specifications and may use excessive space on the bus.

90% to 90% points

10% to 10% points

(Note 5)

10% or 90% of SMBDATA to 10% of SMBCLK

90% of SMBCLK to 10% of SMBDATA

10% of SMBDATA to 90% of SMBCLK

SMBCLK, SMBDATA; 10% to 90% points

SMBCLK, SMBDATA; 90% to 10% points

90% to 90% points

Master clocking in data

CONDITIONS

µs

3

SMBCLK Falling Edge to

SMBDATA Valid Time

µs

4

SMBCLK Clock High Time

µs

4.7

kHz

DC

100

SMBus Clock Frequency

SMBCLK Clock Low Time

ns

300

SMBus Data Hold Time

ns

250

SMBus Data Valid to SMBCLK

Rising Edge Time

µs

4

SMBus STOP Condition Setup

Time

µs

4

SMBus START Condition Hold

Time

µs

1

SMBus Rise Time

ns

300

SMBus Fall Time

µs

4.7

SMBus START Condition

Setup Time

ns

500

SMBus Repeated START

Condition Setup Time

UNITS

MIN

TYP

MAX

SYMBOL

PARAMETER

0

5.0

2.5

10.0

7.5

12.5

15.0

2.5

3.5

4.0

3.0

4.5

5.0

5.5

SUPPLY CURRENT vs. SUPPLY VOLTAGE

SUPPLY VOLTAGE (V)

IOs = 1111 1111 PULLED UP TO +28V

IOs = 0000 0000

0

5.0

2.5

10.0

7.5

12.5

15.0

-40

20

40

-20

0

60

80

100

SUPPLY CURRENT vs. TEMPERATURE

TEMPERATURE (°C)

IOs = 1111 1111 PULLED UP TO +28V

IOs = 0000 0000

0

2

4

6

8

10

12

14

16

02

1

3456

IO_ SINK CURRENT

vs. SUPPLY VOLTAGE

SUPPLY VOLTAGE (V)

Typical Operating Characteristics