1 second

1 Conversion

~11 ms

Standby

Standby

Average of n-2, n-1, n,

and n+1 conversion

result stored

Standby

Standby

nth conversion

(n+1)th conversion

(n+2)th conversion

(n+3)th conversion

(n+4)th conversion

Average of n-1, n, n+1,

and n+2 conversion

result stored

Average of n, n+1,

n+2, and n+3

conversion result

stored

Average of n-3, n-2,

n-1, and n conversion

result stored

Figure 7-4. Conversion (1Hz Conversion Period) With 4x Running Averaging

Averaging can be used in both the continuous conversion mode and the one-shot mode.

7.3.3 Temperature Comparator and Hysteresis

The TMP118 has a temperature comparator feature that uses the THigh_Limit register for high temperature

comparator threshold and the TLow_limit register for low temperature comparator threshold. The low

temperature comparator threshold is used to program the comparator hysteresis. The comparator thresholds

are programmed in the TMP118 in a 12-bit two's complement format and with a resolution of 62.5m°C. The

Alert_Flag bit in the Configuration register is asserted when the temperature result equals or exceeds the

THigh_Limit for a consecutive number of conversions as set by the Fault bits in the Configuration Register,

which can be programmed to 1, 2, 4, or 6 consecutive conversions. The Alert_Flag clears when the temperature

result drops below the TLow_Limit for the same consecutive number of conversions. The difference between the

two limits acts as a hysteresis on the comparator output, and the fault counter prevents false alerts as a result

of environmental temperature fluctuations. The Alert_Flag can be programmed to active low or active high by

configuring the Polarity bit in the Configuration Register.

As shown in Figure 7-5, the alert status becomes active when the temperature equals or exceeds the value in

THigh_Limit for Fault number of consecutive conversions. The alert status remains active until the temperature

falls below the TLow_Limit for the same number of consecutive conversions. The Alert_Flag can also be cleared

by issuing the General Call Reset command.

THigh_Limit

TLow_Limit

(Hysteresis)

Temperature

Conversions

Alert_Flag

(Polarity = 0b)

Alert_Flag

(Polarity = 1b)

Temperature

Figure 7-5. Alert_Flag Behavior

TMP118

SNIS237 – DECEMBER 2024

www.ti.com

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