Logic Electrical Characteristics

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

its apply for T

Symbol

Parameter

Conditions

Typical

Limits

Units

(Note 6)

(Note 7)

(Limit)

SMBDAT, 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)

SMBDAT 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

SMBDAT OUTPUT

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

+3.6 Vdc, C

=T

cations of the SMBus version 2.0. The following parameters are the timing relationships between SMBCLK and SMBDAT sig-

nals related to the LM95221. 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

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

SMBDAT 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 SMBDAT Low to SMBCLK

Low (Start condition hold before the first clock

falling edge)

100

ns (min)

t

SU;STO

Stop Condition SMBCLK High to SMBDAT

Low (Stop Condition Setup)

100

ns (min)

t

SU;STA

SMBus Repeated Start-Condition Setup Time,

SMBCLK High to SMBDAT Low

0.6

µs (min)

t

BUF

SMBus Free Time Between Stop and Start

Conditions

1.3

µs (min)

www.national.com

5