Logic Electrical Characteristics

DIGITAL DC CHARACTERISTICS Unless otherwise noted, these specifications apply for V

limits apply for T

Symbol

Parameter

Conditions

Typical

Limits

Units

(Note 6)

(Note 7)

(Limit)

SMBData, SMBCLK INPUTS

V

IN(1)

Logical “1” Input Voltage

2.1

V (min)

V

IN(0)

Logical “0”Input Voltage

0.8

V (max)

V

IN(HYST)

SMBData and SMBCLK Digital

Input Hysteresis

400

mV

I

IN(1)

Logical “1” Input Current

V

0.005

µA (max)

I

IN(0)

Logical “0” Input Current

V

−0.005

µA (max)

C

IN

Input Capacitance

5

pF

ALL DIGITAL OUTPUTS

I

OH

High Level Output Current

V

10

µA (max)

V

OL

SMBus Low Level Output Voltage

I

I

0.4

0.6

V (max)

SMBus Digital Switching Characteristics

Unless otherwise noted, these specifications apply for V

pF. Boldface limits apply for T

ing characteristics of the LM99 fully meet or exceed the published specifications of the SMBus version 2.0. The following pa-

rameters are the timing relationships between SMBCLK and SMBData signals related to the LM99. They adhere to but are not

necessarily the SMBus bus specifications.

Symbol

Parameter

Conditions

Typical

Limits

Units

(Note 6)

(Note 7)

(Limit)

f

SMB

SMBus Clock Frequency

100

10

kHz (max)

kHz (min)

t

LOW

SMBus Clock Low Time

from V

V

4.7

25

µs (min)

ms (max)

t

HIGH

SMBus Clock High Time

from V

4.0

µs (min)

t

R,SMB

SMBus Rise Time

(Note 12)

1

µs (max)

t

F,SMB

SMBus Fall Time

(Note 13)

0.3

µs (max)

t

OF

Output Fall Time

C

I

250

ns (max)

t

TIMEOUT

SMBData and SMBCLK Time Low for

Reset of Serial Interface (Note 14)

25

35

ms (min)

ms (max)

t

SU;DAT

Data In Setup Time to SMBCLK High

250

ns (min)

t

HD;DAT

Data Out Stable after SMBCLK Low

300

900

ns (min)

ns (max)

t

HD;STA

Start Condition SMBData Low to SMBCLK

Low (Start condition hold before the first

clock falling edge)

100

ns (min)

t

SU;STO

Stop Condition SMBCLK High to SMBData

Low (Stop Condition Setup)

100

ns (min)

t

SU;STA

SMBus Repeated Start-Condition Setup

Time, SMBCLK High to SMBData Low

0.6

µs (min)

t

BUF

SMBus Free Time Between Stop and Start

Conditions

1.3

µs (min)

www.national.com

5