Datasheet

CS
SCLK
DOUT
DIN
1 16
InvalidData
CS
SCLK
DOUT
DIN
1 16 1 16
1 16 1 16
1
16
111111111111
NoWritetothe
ControlRegister
Command:SelectChannelAIN1,
STANDBY=0
NoWritetothe
ControlRegister
Command:EnterStandbyMode,
STANDBY=1
111111111111
InvalidData InvalidData
ConversionResultfor
ChannelAIN1
WaitingforConfiguration InStandbyMode
ConvertingforChannelAIN1
ConvertingforChannelAIN4
InStandbyMode
Command:ExitStandbyMode,
STANDBY=0
WaitingforConfiguration
Command:
SelectChannelAIN4
DeviceEnters
StandbyMode
DeviceExits
StandbyMode
DeviceStartstoExit
StandbyMode
¼
¼
¼
¼
ADS8028
www.ti.com SBAS549B –MAY 2011–REVISED MARCH 2012
It takes four serial transfer cycles for the ADS8028 to exit STANDBY mode and transmit the first valid conversion
data, as shown in Figure 38. The first cycle updates the STANDBY bit to '0'; the second cycle selects the
channels and operation mode; the third cycle converts the selected channel; and the result of this conversion can
be clocked out in the fourth cycle.
Figure 38. STANDBY Mode of Operation
Power-Down Mode
In power-down mode, all internal ADS8028 circuitry (including the internal reference) is powered down and the
Control Register is reset to the default values. The temperature sensor averaging feature is reset and disabled.
The ADS8028 can be placed into power-down mode by pulling the PD/RST pin to a logic low state for at least 90
ns. The PD/RST pin is asynchronous to the clock; thus, it can be triggered at any time regardless of the status of
other ADS8028 pins (including the analog input channels). When the device is in power-down mode, any activity
on the digital input pins (apart from the PD/RST pin) is ignored and the device does not take input-dependent
current from the analog input pins.
The ADS8028 powers up in default condition when the PD/RST pin is pulled back to a logic high level.
Conversions can begin when t
POWER_UP
has elapsed.
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Product Folder Link(s): ADS8028