TLC320V343 Datasheet, PDF (16/30 Pages) Texas Instruments – SINGLE-SUPPLY ANALOG INTERFACE CIRCUIT

TLC320V343
SINGLE-SUPPLY ANALOG INTERFACE CIRCUIT
SLAS159 – MARCH 1997
PARAMETER MEASUREMENT INFORMATION
R
IN + or AUX IN +
R
IN – or AUX IN –
Rfb
_
+
_
+
Rfb
To MUX
Rfb = R for DS03 = 0 and DS02 = 1
Rfb = 2R for DS03 = 1 and DS02 = 0
Rfb = 4R for DS03 = 1 and DS02 = 1
R = 100 kΩ nominal
Figure 2. IN + and IN – Gain-Control Circuitry
Table 1. Gain Control (Analog Input Signal Required for
Full-Scale Bipolar A /D Conversion 2s Complement)^†
INPUT CONFIGURATION
CONTROL REGISTER 4
DS03
DS02
ANALOG INPUT‡
A /D CONVERSION
RESULT
0
0
All
Squelch
Differential configuration
Analog input = IN + – IN –
0
1
VID = ± 3 V
= AUX IN + – AUX IN –
1
0
VID = ± 1.5 V
± Full scale
± Full scale
1
1
VID = ± 0.75 V
± Full scale
0
0
All
Squelch
Single-ended configuration§
Analog input = IN + – VMID
= AUX IN + – VMID
0
1
VI = ± 1.5 V
1
0
VI = ± 1.5 V
± Half scale
± Full scale
1
1
VI = ± 0.75 V
± Full scale
† _{VDD = 5 V}
‡ _{VID = differential input voltage, VI = input voltage referenced to ADC VMID with IN – or AUX IN – connected to ADC VMID. In order to minimize}
distortion, it is recommended that the analog input not exceed 0.1 dB below full scale.
§ _{For single-ended inputs, the analog input voltage must not exceed the supply rails. All single-ended inputs must be referenced to the internal}
reference voltage, ADC VMID, for best common-mode performance.
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