Texas Instruments ADS1x9xECG-FE, User Manual

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ADS1x9xECG-FE Hardware Introduction
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Sl NO Test Point Description
1 TP25 3.3 V
2 TP32 ADS_AVDD, 3.0 V
5.2 Clock
The ADS1x9x includes an on-chip circuit which generates a 512 kHz clock, ±2% over temperature. For
application requiring higher accuracy the ADS1x9x can also use an external clock signal. The
demonstration kit provides the firmware option to select either an internal or external clock for testing. The
demonstration kit also provides the option to generate an external clock for the ADC from the MSP430 or
onboard oscillator.
Oscillators O2 (24MHz) and O3 (32.768 KHz) are used by the micro-controller.
Clock Type R21 R24 Clock SEL
Mount R77 to Drive “high” on ADC_CLK_SCL
Internal Clock Not Installed Not Installed OR
Set P2.3 of MSP430 to Drive “high” on ADC_CLK_SCL.
Mount R76 to Drive “low” on ADC_CLK_SCL
External Clock Not Installed Installed OR
Clear P2.3 of MSP430 to Drive “low” on ADC_CLK_SCL.
5.3 Memory
ADS1x9xECG-FE has 8GB NAND Flash memory (U14) installed for data storage.
5.4 Accessing ADS1x9x Digital Signals
ADS1x9x SPI interface with MSP430 can be accessed through the test points given in the table below:
Sl NO. Signal Test Points
1 ADC_CS TP24
2 ADC_START TP56
3 ADC_DOUT TP47
4 ADC_SCLK TP11
5 ADC_DIN TP46
6 ADC_DRDY TP52
7 ADC_RESET TP53
8 CLK TP42
5.5 GPIO Test Points
There are two GPIO connections between the ADS1x9x and the MSP430 micro-controller, which are
accessible through the test points given in the table below:
Sl NO. Signal Test Points
1 ADC_GPIO1 TP15
2 ADC_GPIO2 TP16
5.6 Analog Inputs
The ADS1x9xECG-FE gives the user the option to feed in the standard ECG/Respiration signals from a
patient simulator to the DB9 connector (P5).
The output from any typical patient simulator can be directly fed into the DB9 connector. For all
measurements in this user guide a Fluke medSim 300B simulator was used as shown in
Figure 33 .
28 ADS1x9xECG-FE Demonstration Kit SLAU384A – December 2011 – Revised April 2012
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