Startup

Start of

Conversion

Delay

(1)

27 ms

Start of

Conversion

Delay

(1)

27 ms

27 ms

15

TMP108

www.ti.com

SBOS663A – APRIL 2013 – REVISED SEPTEMBER 2019

Product Folder Links: TMP108

Submit Documentation Feedback

Copyright © 2013–2019, Texas Instruments Incorporated

After power-up or a general-call reset, the TMP108 immediately starts a conversion, as shown in Figure 12. The

first result is available after 27 ms (typical). The active quiescent current during conversion is 40 μA (typical at

+25°C). The quiescent current during delay is 0.7 μA (typical at +25°C).

(1)

Delay is set by the CR1 and CR0 bits in the configuration register.

Figure 12. Conversion Start

7.5.4 High- and Low-Limit Registers

In comparator mode (TM = 0), the ALERT pin becomes active when the temperature exceeds the value in the

THIGH register or drops below the value in the TLOW register. The ALERT pin remains active until the temperature

returns to a value that is within the range set by:

(TLOW + HYS) and (THIGH – HYS)

where

•

HYS is the hysteresis set by the hysteresis control bits (HYS1 and HYS0).

(1)

In interrupt mode (TM = 1), the ALERT pin becomes active when the temperature exceeds the value in the THIGH

register or drops below the value in the TLOW register, and remains active until a read operation of the

configuration register occurs (also clears the values latched in the watchdog flags, FL and FH), or the device

successfully responds to the SMBus alert response address. The ALERT pin is also cleared by resetting the

device with the general call reset command.

Both operational modes are represented in Figure 13 and Figure 14.

Table 11 and Table 12 describe the format for the THIGH and TLOW registers. Note that the most significant byte is

sent first, followed by the least significant byte. Power-up (reset) default values are THIGH = +127.9375°C

(0x7FF8) and TLOW = –128°C (0x8000). These values ensure that upon power-up, the limit window is set to

maximum, and the ALERT pin does not become active until the desired limit values are programmed in the

registers. Other default values for the temperature limits are available by request. The format of the data for

THIGH and TLOW is the same as for the temperature register.

Table 11. Bytes 1 and 2 of THIGH Register

BYTE

D7

D6

D5

D4

D3

D2

D1

D0

1

H11

H10

H9

H8

H7

H6

H5

H4

BYTE

D7

D6

D5

D4

D3

D2

D1

D0

2

H3

H2

H1

H0

0

0

0

0

Table 12. Bytes 1 and 2 of TLOW Register

BYTE

D7

D6

D5

D4

D3

D2

D1

D0

1

L11

L10

L9

L8

L7

L6

L5

L4

BYTE

D7

D6

D5

D4

D3

D2

D1

D0

2

L3

L2

L1

L0

0

0

0

0