Single_chip_low_noise_wideband_amplifier_with_external_gain_AGC

Published:2009/7/24 0:15:00 Author:Jessie | From:SeekIC

The SL550 used in this circuit is a general-purpose wideband linear amplifier with remote gain/AGC control. Figure 2-4B shows the electrical charac-teristics. Figure 2-4C shows frequency response. The input capacitance (typically 12 pF at 60 MHz) is independent of frequency. The input resistance (about 1.5 kΩ at 10 MHz) decreases with frequency and is typically 500Ω at 60 MHz. Typical gain/ACC voltage is 0.6 V (Ic=1μA) to 0.8 v (IC= 2 mA) applied to pins 2 and 3 (Fig. 2-4D). If full output swing is not required, omit R1, as shown in Fig. 2-4B.A high-impedance output current can be obtained by taking the output from pin 6 (with pin 7 open circuit). Maximum output current is 2 mA peak, with an output impedance of 350 Ω. Gain variation with temperature can be reached (at the expense of noise figure) by decoupling pin 13 and leaving pin 12 open circuit, as shown in Figs. 2-4E and 2-4F. A low input impedance (25 Ω) can be obtained by decoupling pin 11 and applying the input to pin 12 (with pin 13 open circuit). R2 eliminates high-frequency instability, and it can be omitted of the IC is soldered directly to a PC board.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Electrical_Equipment_Circuit/Single_chip_low_noise_wideband_amplifier_with_external_gain_AGC.html

Print this Page | Comments | Reading(3)