THS6072 Datasheet, PDF (12/31 Pages) Texas Instruments – LOW-POWER ADSL DIFFERENTIAL RECEIVER

THS6072
LOW-POWER ADSL DIFFERENTIAL RECEIVER
SLOS290B – FEBRUARY 2000 – REVISED JUNE 2001
APPLICATION INFORMATION
theory of operation
The THS6072 is a high-speed, operational amplifier configured in a voltage feedback architecture. It is built
using a 30-V, dielectrically isolated, complementary bipolar process with NPN and PNP transistors possessing
f_Ts of several GHz. This results in an exceptionally high performance amplifier that has a wide bandwidth, high
slew rate, fast settling time, and low distortion. A simplified schematic is shown in Figure 39.
(7) VCC +
IN – (2,6)
(1,7) OUT
IN + (3,5)
Figure 39. THS6072 Simplified Schematic
(4) VCC –
noise calculations and noise figure
Noise can cause errors on very small signals. This is especially true when amplifying small signals, where
signal-to-noise ratio (SNR) is very important. The noise model for the THS6072 is shown in Figure 40. This
model includes all of the noise sources as follows:
• e_n = Amplifier internal voltage noise (nV/√Hz)
• IN+ = Noninverting current noise (pA/√Hz)
• IN– = Inverting current noise (pA/√Hz)
• e_Rx = Thermal voltage noise associated with each resistor (e_Rx = 4 kTR_x )
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