ADC121C021_14 Datasheet, PDF (20/44 Pages) Texas Instruments – I2C-Compatible, 12-Bit Analog-to-Digital Converter with Alert Function

ADC121C021, ADC121C021Q, ADC121C027
SNAS415F – JANUARY 2008 – REVISED MARCH 2013
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Bits
Name
7:5
Cycle Time
4
Alert Hold
3
Alert Flag Enable
2
Alert Pin Enable
1
Reserved
0
Polarity
Description
Configures Automatic Conversion mode. When these bits are set to zeros, the automatic conversion
mode is disabled. This is the case at power-up.
When these bits are set to a non-zero value, the ADC will begin operating in automatic conversion
mode (see Automatic Conversion Mode). The Cycle Time table shows how different values provide
various conversion intervals.
0: Alerts will self-clear when the measured voltage moves within the limits by more than the hysteresis
register value.
1: Alerts will not self-clear and are only cleared when a one is written to the alert high flag or the alert
low flag in the Alert Status register.
0: Disables alert status bit [D15] in the Conversion Result register.
1: Enables alert status bit [D15] in the Conversion Result register.
0: Disables the ALERT output pin. The ALERT output will be high impedance when the pin is disabled.
1: Enables the ALERT output pin.
*This bit does not apply to and is a "don't care" for the ADC121C027.
Always reads zeros. Zeros must be written to this bit.
This bit configures the active level polarity of the ALERT output pin.
0: Sets the ALERT pin to active low.
1: Sets the ALERT pin to active high.
*This bit does not apply to and is a "don't care" for the ADC121C027.
V_LOW -- Alert Limit Register - Under Range
This register holds the lower limit threshold used to determine the alert condition. If the conversion moves lower
than this limit, a V_LOW alert is generated.
Pointer Address 03h (Read/Write)
Default Value: 0000h
D15
D14
D13
D12
D11
D10
D9
D8
Reserved
V_LOW Limit [11:8]
D7
D6
D5
D4
D3
D2
D1
D0
V_LOW Limit [7:0]
Bits
15:12
11:0
Name
Reserved
V_LOW Limit
Description
Always reads zeros. Zeros must be written to these bits.
Lower limit threshold. D11 is MSB.
20
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