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ADT7518
Table 30.
Bit
C0
Rev. A | Page 29 of 40
Function
This bit enables/disables conversions in round robin
and single-channel mode. ADT7518 powers up in round
robin mode but monitoring is not initiated until this bit
is set. The default = 0.
0 = Stop monitoring.
1 = Start monitoring.
C2:C1 Selects between the two different analog inputs on Pins
7 and 8. ADT7518 powers up with AIN1 and AIN2
selected.
00 = AIN1 and AIN2 selected.
01 = Undefined.
10 = External TDM selected.
11 = Undefined.
C3
Selects between digital (LDAC) and analog inputs (AIN3)
on Pin 9. When AIN3 is selected, Bit C3 of the Control
Configuration 3 register is masked and has no effect
until LDAC is selected as the input on Pin 9.
0 = LDAC selected.
1 = AIN3 selected.
C4
Reserved. Write 0 only.
C5
0 = Enable INT/INT output.
1 = Disable INT/INT output.
C6
Configures INT/INT output polarity.
0 = Active low.
1 = Active high.
PD
Power-Down Bit. Setting this bit to 1 puts the ADT7518
into standby mode. In this mode, both ADC and DACs
are fully powered down, but the serial interface is still
operational. To power up the part again, just write 0 to
this bit.
Control Configuration 2 Register (Read/Write)
[Address = 19h]
This configuration register is an 8-bit read/write register that is
used to set up some of the operating modes of the ADT7518.
Table 31. Control Configuration 2
D7
D6
D5
C7
C6
C5
0*
0*
0*
D4
C4
0*
D3
C3
0*
D2
C2
0*
D1
C1
0*
D0
C0
0*
*
Default settings at power-up
Table 32.
Bit
Function
C2:0 In single-channel mode, these bits select between V
DD
,
the internal temperature sensor, external temperature
sensor/AIN1, AIN2, AIN3, and AIN4 for conversion. The
default is V
DD
.
000 = V
DD
.
001 = Internal temperature sensor.
010 = External temperature sensor/AIN1. (Bits C1:C2 of
the Control Configuration 1 register affect this selection).
011 = AIN2.
100 = AIN3.
Bit
Function
101 = AIN4.
110–111 = Reserved.
Reserved.
Selects between single-channel and round robin conver-
sion cycle. The default is round robin.
0 = Round robin.
1 = Single channel.
Default condition is to average every measurement on all
channels 16 times. This bit disables this averaging.
Channels affected are temperature, analog inputs, and
V
DD
.
0 = Enable averaging.
1 = Disable averaging.
SMBus timeout on the serial clock puts a 25 ms limit on
the pulse width of the clock, ensuring that a fault on the
master SCL does not lock up the SDA line.
0 = Disable SMBus timeout.
1 = Enable SMBus timeout.
Software Reset. Setting this bit to 1 causes a software
reset. All registers and DAC outputs will reset to their
default settings.
C3
C4
C5
C6
C7
Control Configuration 3 Register (Read/Write)
[Address = 1Ah]
This configuration register is an 8-bit read/write register that is
used to set up some of the operating modes of the ADT7518.
Table 33. Control Configuration 3
D7
D6
D5
C7
C6
C5
0*
0*
0*
D4
C4
0*
D3
C3
0*
D2
C2
0*
D1
C1
0*
D0
C0
0*
*
Default settings at power-up
Table 34.
Bit
Function
C0
Selects between fast and slow ADC conversion speeds.
0 = ADC clock at 1.4 kHz.
1 = ADC clock at 22.5 kHz. D+ and D– analog filters are
disabled.
C2:1
Reserved. Write 0 only.
C3
0 = LDAC pin controls updating of DAC outputs.
1 = DAC configuration register and LDAC configuration
register control updating of DAC outputs.
C4
Selects the ADC reference to be either internal V
REF
or V
DD
for analog inputs.
0 = Internal V
REF.
1 = V
DD
.
C5
Setting this bit selects DAC A voltage output to be
proportional to the internal temperature measurement.
C6
Setting this bit selects DAC B voltage output to be
proportional to the external temperature measurement.
C7
Reserved. Write 0 only.