AMC6821 datasheet(14/54 Pages) TI

14 / 54 page

www.ti.com

Temperature Out-of-Range Detection

AMC6821

SBAS386C – MAY 2006 – REVISED JULY 2007

Table 11. Temperature Data Format

TEMPERATURE (

°C)

BINARY DIGITAL CODE (11 bits)

+127

01111111000

+125

01111101000

+100

01100100000

+75

01001011000

+50

00110010000

+25

00011001000

+10

00001010000

00000001000

00000000000

–1

11111111000

–25

11100111000

–50

11001110000

–75

10110101000

–100

10011100000

–125

10000011000

–128

10000000000

The AMC6821 has the following temperature limitation detections:

1. High and Low Temperature Limit: The value of the High-Temp-Limit and Low-Temp-Limit registers specify

the remote or local temperature ranges of normal operation. When the local or remote temperatures are

equal to or above the value of the corresponding High-Temp-Limit register, the LTH or RTH bits in the status

corresponding Low-Temp-Limit register, the LTL or RTL bits in the status register are set ('1').

When the local temperature is out-of-range (LTH = 1 or LTL = 1), the local temperature out-of-range event

occurs. The LTO bit in the status register is set ('1'), and the LTO interrupt is generated via the SMBALERT

pin if it is enabled (the LTOIE bit of Configuration Register 2 is set). Similarly, when the remote temperature

is out-of range (RTH = 1 or RTL = 1), the remote temperature out-of-range event occurs. The RTO bit in the

status register is set ('1'), and the RTO interrupt is generated via the SMBALERT pin if it is enabled (that is,

the RTOIE bit of Configuration Register 2 is set).

2. Critical Limit: Critical temperature limit is the highest allowed of remote or local temperature. When the

temperature is greater than or equal to the corresponding critical temperature, the LTCT or RTCT bit of the

status register is set ('1'), the output of the OVR pin goes low, and a non-maskable interrupt is generated

through the SMBALERT pin (low).

3. Passive Cooling Temperature (PSV) Limit: This limit defines the passive cooling threshold. In the auto

remote-temperature-fan control mode, the system enters a passive cooling condition when the remote

temperature is equal to or below this limit, and the fan stops. In the maximum fast speed calculated control

mode, the fan stops and the system enters a passive cooling condition when both the remote and local

temperatures are equal to or below this limit. In passive cooling, the LPSV bit of Status Register 2 (0x03) is

set ('1'), and a PSV interrupt is generated on the SMBALERT pin if enabled (PSVIE = 1). Note that reading

the Status Register clears the LPSV bit. After reading, if the active control temperature remains equal to or

below the PSV temperature, this bit reasserts on next monitoring cycle.

Submit Documentation Feedback

Product Folder Link(s): AMC6821

AMC6821 Datasheet(PDF) 14 Page - Texas Instruments

AMC6821 Datasheet(HTML) 14 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54

Datasheet Download

Link URL