TSH310

Power Supply Considerations

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4 Power Supply Considerations

Correct power supply bypassing is very important for optimizing performance in high-frequency ranges.

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 10nF can be added using the same implementation conditions. Bypass

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

For example: on the SO8_SINGLE_HF board, these capacitors are C6, C7, C8, C9.

Single power supply

In the event that a single supply system is used, new biasing is necessary to assume a positive output

will provide an output dynamic from +0.9V to +4.1V on 1k

Ω load.

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

max.) as the 1% of the current through the resistance divider to keep a stable mid-supply, two resistances

of 470

Ω can be used.

The input provides a high pass filter with a break frequency below 10Hz which is necessary to remove the

Figure 27 illustrates a 5V single power supply configuration for the SO8_SINGLE evaluation board (see

Evaluation Boards on page 9).

Figure 26: Circuit for power supply bypassing

+

10microF

+

10nF

10microF

+

10nF

-

+

10microF

+

10nF

10microF

+

10nF

-