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THS4131 Datasheet, PDF (14/37 Pages) National Semiconductor (TI) – HIGH-SPEED, LOW-NOISE, FULLY-DIFFERENTIAL I/O AMPLIFIERS | |||
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THS4130
THS4131
SLOS318H â MAY 2000 â REVISED MAY 2011
www.ti.com
DATA CONVERTERS
Data converters are one of the most popular applications for the fully-differential amplifiers. Figure 30 shows a
typical configuration of a fully-differential amplifier attached to a differential analog-to-digital converter (ADC).
0.1 µF
VCC
5V
VIN
+â
VOCM
â+
â5 V
VCCâ
VDD
AVDD DVDD
AIN1
AIN2 AVSS
Vref
Figure 30. Fully-Differential Amplifier Attached to a Differential ADC
Fully-differential amplifiers can operate with a single supply. VOCM defaults to the midrail voltage, VCC/2. The
differential output may be fed into a data converter. This method eliminates the use of a transformer in the circuit.
If the ADC has a reference voltage output (Vref), then it is recommended to connect it directly to the VOCM of the
amplifier using a bypass capacitor for stability. For proper operation, the input common-mode voltage to the input
terminal of the amplifier should not exceed the common-mode input voltage range.
0.1 µF
VCC
5V
VIN
+â
VOCM
â+
VDD
AVDD DVDD
AIN1
AIN2 AVSS
Vref
Figure 31. Fully-Differential Amplifier Using a Single Supply
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Copyright © 2000â2011, Texas Instruments Incorporated
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