AMC7836_15 Datasheet, PDF (34/87 Pages) Texas Instruments – AMC7836 High-Density, 12-Bit Analog Monitor and Control Solution With Multichannel ADC, Bipolar DACs, Temperature Sensor, and GPIO Ports

AMC7836
SLAS986B – NOVEMBER 2014 – REVISED FEBRUARY 2015
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7.3.2.4.1 Unipolar Inputs Out-of-Range Alarms
The AMC7836 device provides out-of-range detection for the five external unipolar ADC inputs (LV_ADC16
through LV_ADC20, pins 35 through 39). Figure 55 shows the out-of-range detection block. When the
measurement is out-of-range, the corresponding alarm bit in the alarm status 0 register (address 0x70) is set to 1
to flag the out-of-range condition. The values in the ADC upper and lower Threshold registers (address 0x80
through 0x93) define the upper and lower bound thresholds for all five inputs.
ADCn-Upper-
Threshold Value
±
(upper bound)
+
LV_ADCn
Conversion Value
(n = 16 to 20)
ADCn-ALR
Bit
±
ADCn-Lower-
Threshold Value
+
(lower bound)
Figure 55. Unipolar Inputs Out-of-Range Alarms
7.3.2.4.2 Unipolar Inputs Out-of-Range Alarms
The AMC7836 includes high-limit and low-limit detection for the internal temperature sensor. Figure 56 shows the
temperature detection block. The values in the LT upper and lower threshold registers (address 0x94 through
0x97) set the limits for the temperature sensor. The temperature sensor detector can issue either a high-alarm
(LT-HIGH-ALR bit) or a low-alarm (LT-LOW-ALR bit) in the alarm status 1 register (address 0x71) depending on
whether the high or low thresholds were exceeded. To implement single, upper-bound threshold detection for the
temperature sensor, the host processor can set the upper-bound threshold to the desired value and the lower-
bound threshold to the default value. For lower-bound threshold detection, the host processor can set the lower-
bound threshold to the desired value and the upper-bound threshold to the default value.
In addition to the programmable threshold alarms the temperature sensor detection circuit also includes a die
thermal-alarm flag which continuously monitors the die temperature. When the die temperatures exceeds 150˚C
the die thermal alarm flag (THERM-ALR bit) in the alarm status 1 register (address 0x71) is set. The internal
temperature sensor must be enabled for this alarm to be functional.
Temperature
High Threshold
±
(upper bound)
+
LT-HIGH-ALR Bit
Temperature
Data
150°C _±
+
THERM-ALR Bit
±
Temperature
Low Threshold
+
(lower bound)
LT-LOW-ALR Bit
Figure 56. Internal Temperature Out-of-Range Alarms
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