THS10082_09 Datasheet, PDF (31/37 Pages) Texas Instruments – 10-BIT, TWO ANALOG INPUT, 8-MSPS, SIMULTANAEOUS SAMPLING

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THS10082
SLAS254B − MAY 2002 − REVISED NOVEMBER 2002
INTERFACING THE THS10082 TO THE TMS320C6201 DSP
The following application circuit shows an interface of the THS10082 to the TMS320C6201. The read (using RD,
RD-controlled) and write timings (using WR, WR-controlled) shown before are valid for this specific interface.
THS10082−1
TMS320C6201
CS0
CS1
RD
WR
DATA_AV
DATA
CONV_CLK
THS10082−2
CE1
EA20
ARE
AWE
EXT_INT6
DATA
TOUT1
TOUT2
EA21
EXT_INT7
CS0
CS1
RD
WR
DATA_AV
DATA
CONV_CLK
ANALOG INPUT CONFIGURATION AND REFERENCE VOLTAGE
The THS10082 features two analog input channels. These can be configured for either single-ended or differential
operation. Best performance is achieved in differential mode. Figure 40 shows a simplified model, where a single-ended
configuration for channel AINP is selected. The reference voltages for the ADC itself are V_REFP and V_REFM (either internal
or external reference voltage). The analog input voltage range goes from V_REFM to V_REFP. This means that V_REFM defines
the minimum voltage, which can be applied to the ADC. V_REFP defines the maximum voltage, which can be applied to the
ADC. The internal reference source provides the voltage V_REFM of 1.5 V and the voltage V_REFP of 3.5 V. The resulting
analog input voltage swing of 2 V can be expressed by:
VREFM v AINP v VREFP
(1)
VREFP
AINP
10-Bit
ADC
VREFM
Figure 40. Single-Ended Input Stage
A differential operation is desired for many applications. Figure 41 shows a simplified model for the analog inputs AINM
and AINP, which are configured for differential operation. This configuration has a few advantages, which are discussed
in the following paragraphs.
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