RHF310

Power supply considerations

Doc ID 15577 Rev 3

11/22

3

Power supply considerations

Correct power supply bypassing is very important for optimizing the performance of the

device in high-frequency ranges. The bypass capacitors should be placed as close as

possible to the IC pins to improve high-frequency bypassing. A capacitor greater than 1 µF

is necessary to minimize the distortion. For better quality bypassing, a capacitor of 10 nF

can be added, which should also be placed as close as possible to the IC pins. The bypass

capacitors must be incorporated for both the negative and positive supply.

Figure 22.

Circuit for power supply bypassing

3.1

Single power supply

If you use a single-supply system, biasing is necessary to obtain a positive output dynamic

amplifier provides an output swing from +0.9 V to +4.1 V on 1 k

Ω loads.

DC component of the signal at this value. Several options are possible to provide this bias

supply, such as a virtual ground using an operational amplifier or a two-resistance divider

(which is the cheapest solution). A high resistance value is required to limit the current

consumption. On the other hand, the current must be high enough to bias the non-inverting

input of the amplifier. If we consider this bias current (55 µA maximum) as 1% of the current

through the resistance divider, two resistances of 470

Ω can be used to maintain a mid

supply.

The input provides a high-pass filter with a break frequency below 10 Hz, which is

necessary to remove the original 0 V DC component of the input signal and to set it at

Figure 23 on page 12 illustrates a 5 V single power supply configuration.

and its value is calculated with a consideration of the cut-off frequency of this low-pass filter.

+

+V

CC

10 µF

+

10 nF

10 µF

+

10 nF

-

-V

CC

AM00835