ADT7481

http://onsemi.com

3

PIN ASSIGNMENT

Pin No.

Mnemonic

Description

1

Positive Supply, 3.0 V to 3.6 V.

2

D1+

Positive Connection to the Remote 1 Temperature Sensor.

3

D1−

Negative Connection to the Remote 1 Temperature Sensor.

4

THERM

Open−Drain Output. Requires pullup resistor. Signals overtemperature events, could be used to turn a

fan on/off, or throttle a CPU clock.

5

GND

Supply Ground Connection.

6

D2−

Negative Connection to the Remote 2 Temperature Sensor.

7

D2+

Positive Connection to the Remote 2 Temperature Sensor.

8

ALERT/THERM2

Open−Drain Logic Output. Used as interrupt or SMBALERT. This may also be configured as a second

THERM output. Requires pullup resistor.

9

SDATA

Logic Input/Output, SMBus Serial Data. Open−Drain Output. Requires pullup resistor.

10

SCLK

Logic Input, SMBus Serial Clock. Requires pullup resistor.

Parameter

Unit

Description

400

kHz max

4.7

ms min

Clock low period, between 10% points

4.0

ms min

Clock high period, between 90% points

1.0

ms max

Clock/data rise time

300

ns max

Clock/data fall time

4.7

ms min

Start condition setup time

(Note 2)

4.0

ms min

Start condition hold time

(Note 3)

250

ns min

Data setup time

(Note 4)

4.0

ms min

Stop condition setup time

4.7

ms min

Bus free time between stop and start conditions

1. Guaranteed by design, not production tested.

2. Time from 10% of SDATA to 90% of SCLK.

3. Time for 10% or 90% of SDATA to 10% of SCLK.

4. Time for 90% of SCLK to 10% of SDATA.

Figure 2. Serial Bus Timing

SCLK

SDATA

STOP START

STOP

START