Texas Instruments ADS8364 Bipolar Input to Channel A0, Typical Analog Input Buffer Circuit Values

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Analog Interface

NOTE: Components marked NI are NOT INSTALLED.

Figure 1. Channel A0 Input Circuit

This configuration allows single-ended signals of ±2.5 V (+5 Vpp) to be applied to either input of channel A0 (J2 pin 1 or 3 referenced to pin 2). The input also can be applied to connector J4 (not shown) pins 2 or 4, referenced to analog ground.

3.2Bipolar Input to Channel A0

By changing components and setting the appropriate jumper, it is possible to configure the input buffer to accept bipolar input voltages. Table 1 is related to the schematic presented in Figure 1 and represents just a few of the possible input configurations.

Table 1. Typical Analog Input Buffer Circuit Values

	Input Voltage		R3	R2	R1	R4	W2
			R28	R25	R24	R29	W1
Refer to Figure 1	Default		open	5kΩ	5kΩ	5 kΩ	1–2
	0 – +5
	0 – 2.5		5 kΩ	5 kΩ	open	5 kΩ	2–3
	– 2.5	– +2.5	20 kΩ	4 kΩ	20 kΩ	4 kΩ	2–3
	– 5	– +5	20 kΩ	4 kΩ	10 kΩ	2 kΩ	2–3
	– 10	– +10	20 kΩ	4 kΩ	5 kΩ	1 kΩ	2–3

SLAU189 –September 2006	ADS8364/65MEVM	3
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