THS4012CDGNR Datasheet, PDF (12/35 Pages) Texas Instruments – 290-MHz LOW-DISTORTION HIGH-SPEED AMPLIFIERS

THS4011
THS4012
SLOS216E – JUNE 1999 – REVISED APRIL 2010
www.ti.com
APPLICATION INFORMATION
THEORY OF OPERATION
The THS401x 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 24.
7
V_CC +
2
IN −
6
OUT
3
IN +
1
8
NULL
NULL
Pin numbers are for the D, DGN, and JG packages.
Figure 24. THS4011/4012 Simplified Schematic
4
V_CC −
Noise Calculations and Noise Figure (NF)
Noise can cause errors on very small signals. This is especially true when amplifying small signals. The noise
model for the THS401x is shown in Figure 25. 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)
12
Submit Documentation Feedback
Copyright © 1999–2010, Texas Instruments Incorporated
Product Folder Link(s): THS4011 THS4012