Texas Instruments AFE4490 Evaluation Module AFE4490SPO2EVM AFE4490SPO2EVM Datenbogen
Produktcode
AFE4490SPO2EVM
AFE44x0SPO2EVM FAQs
9.4
Using an external ADC (Bypass ADC mode) (Available only for AFE4490 device)
AFE4490 has a mode where the front-end analog output voltage becomes available on two pins
(RX_OUTP, RX_OUTN), around a common-mode voltage of ~ 0.9 V. In this mode, the internal ADC of
AFE4490 is disabled, one of the internal ADC_RESET clocks is brought out on the PD_ALM pin (PD_ALM
is monitored at series jumper resistor R37). This signal is used to convert each of the four phases (with
every pulse repetition period). Additionally the ADC_RDY signal (ADC_RDY is monitored at series jumper
resistor R26) is used to synchronize the external ADC with the AFE.
(RX_OUTP, RX_OUTN), around a common-mode voltage of ~ 0.9 V. In this mode, the internal ADC of
AFE4490 is disabled, one of the internal ADC_RESET clocks is brought out on the PD_ALM pin (PD_ALM
is monitored at series jumper resistor R37). This signal is used to convert each of the four phases (with
every pulse repetition period). Additionally the ADC_RDY signal (ADC_RDY is monitored at series jumper
resistor R26) is used to synchronize the external ADC with the AFE.
9.5
Diagnostics
The device includes diagnostics to detect open or short conditions of the LED and photo-sensor, LED
current profile feedback, and cable on or off detection. The EVM supports the diagnostic feature of the
device.
current profile feedback, and cable on or off detection. The EVM supports the diagnostic feature of the
device.
The diagnostic feature is enabled from the Global Settings under the Device Configuration tab. Clicking
the Diagnostic Enable button enables the diagnostic function and once the diagnostic function is
completed, the status of the fault flags are updated on the Global Settings tab.
the Diagnostic Enable button enables the diagnostic function and once the diagnostic function is
completed, the status of the fault flags are updated on the Global Settings tab.
shows the
diagnostic mode fault flags when no finger pulse oximeter sensor was connected to the EVM.
Figure 42. Diagnostic Feature Fault Flags with No Finger Sensor Connected to the EVM
9.6
Automation of Register Read and Write Operations
Refer to the Scripting document located in the Documentation directory for detailed instruction on how to
use automation functions for register read and write operations.
use automation functions for register read and write operations.
Documentation directory is located at the following location:
•
On a Windows XP machine – C:\Program Files\Texas Instruments\AFE44x0SPO2EVM
GUI\Documentation
GUI\Documentation
•
On a Windows 7 machine – C:\Program Files(x86)\Texas Instruments\AFE44x0SPO2EVM
GUI\Documentation
GUI\Documentation
37
SLAU480A – January 2013 – Revised February 2013
AFE4400 and AFE4490 Development Guide
Copyright © 2013, Texas Instruments Incorporated