Voltage Controlled Attenuator

This typical circuit uses an external op amp for better performance and an exponential converter to get a control characteristic of -6 dB/V. Trim networks are shown to null out distortion and dc shift, and to fine trim gain to 0 dB with 0 V of control voltage.

Click para ampliar

Seguir leyendo

Variable Attenuator

The PN4391 provides a low Rds(on) (less then 30 ohms). The tee attenuator provides for optimum dynamic linear range for attenuation and if complete turn-off is desired, attenuation of greater then 100 dB can be obtained at 10 MHz providing proper RF construction techniques are employed.

Click para ampliar

Seguir leyendo

Digitally Selectable Precision Attenuator

• Accuracy of better then 0.4% with standard 1% value resistors
• No offset adjustment necessary
• Expandable to any number of stages
• Very high input impedance
  

A1	A2	A3	Vo ATTENUATION
0	0	0	0
0	0	1	-1dB
0	1	0	-2dB
0	1	1	-3dB
1	0	0	-4dB
1	0	1	-5dB
1	1	0	-6dB
1	1	1	-7dB

Click para ampliar

Seguir leyendo