Texas Instruments MSC1211 manual 4 J4 Analog Inputs, 5 J7 External Reference Input

I/O Connectors and Signals

3.3.4J4: Analog Inputs

Terminal block J4 is the main analog input to the MSC1211EVM, as is defined in Table 3–8. One terminal is provided for each of the nine MSC1211 differen- tial inputs. Each terminal is connected to the MSC1211 through a 1kΩ resistor.

Table 3–8. J4: Analog Inputs

Terminal	Terminal	MSC1211
Number	Name	Pin Number	Function
1	AN0	18	Analog Input 0
2	AN1	19	Analog Input 1
3	AN2	20	Analog Input 2
4	AN3	21	Analog Input 3
5	AN4	22	Analog Input 4
6	AN5	23	Analog Input 5
7	AN6/EXTD	24	Analog Input 6 and
			Digital Low Voltage Detect
8	AN7/EXTA	25	Analog Input 7 and
			Analog Low Voltage Detect
9	AINCOM	26	Analog Common
10	AGND	17, 27	Analog Ground

3.3.5J7: External Reference Input

The MSC1211EVM has an onboard 2.5V/1.25V bandgap reference. If a lower- noise reference source or a reference with a different voltage is desired, it can be connected to square pin connector J7. The reference source (onboard or external) is selected using pins 1 and 2 of J7. Bypassing for the reference in- puts is provided by C17 and C18. To use the internal REFOUT signal, connect pins 1 and 2 together.

Table 3–9. J7: External Reference Input

Terminal
Number	Function
1	AGND— Analog Ground
2	REF IN–
3	VDAC1/(REF+ for MSC1211)
4	REF IN+/REFOUT
5	Open
6	AVDD

Operation3-9