TMP411

SBOS383A − FEBRUARY 2007

www.ti.com

6

APPLICATIONS INFORMATION

The TMP411 is a dual-channel digital temperature sensor

that combines a local die temperature measurement

channel and a remote junction temperature measurement

channel in a single MSOP-8 or SO-8 package. The

TMP411 is Two-Wire- and SMBus interface-compatible

and is specified over a temperature range of −40

°C to

+125

°C. The TMP411 contains multiple registers for

holding

configuration

information,

temperature

measurement

results,

temperature

comparator

maximum/minimum limits, and status information.

User-programmed high and low temperature limits stored

in the TMP401 can be used to monitor local and remote

temperatures to trigger an over/under temperature alarm

(ALERT). Additional thermal limits can be programmed

into the TMP411 and used to trigger another flag (THERM)

that can be used to initiate a system response to rising

temperatures.

The TMP411 requires only a transistor connected between

D+ and D− for proper remote temperature sensing

operation. The SCL and SDA interface pins require pull-up

resistors as part of the communication bus, while ALERT

and THERM are open-drain outputs that also need pull−up

resistors. ALERT and THERM may be shared with other

devices if desired for a wired-OR implementation. A 0.1

µF

power-supply bypass capacitor is recommended for good

local bypassing. Figure 11 shows a typical configuration

for the TMP411.

0.1

µF

10k

Ω

(typ)

10k

Ω

(typ)

10k

Ω

(typ)

10k

Ω

(typ)

TMP411

D+

D

−

V+

1

8

7

6

4

5

3

2

R

S

(2)

R

S

(2)

C

DIFF

(3)

C

DIFF

(3)

R

S

(2)

R

S

(2)

GND

SCL

SDA

ALERT/THERM2

THERM

+5V

SMBus

Controller

Fan Controller

Series Resistance

(1) Diode−connected configuration provides better settling time.

Transistor−connected configuration provides better series resistance cancellation.

(2) R

(3) C

NOTES:

Figure 11. Basic Connections