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To design a low-noise power supply for the 24-bit ADC device, consider using a combination of a low-dropout regulator (LDO) and passive filtering components. The LDO provides stable voltage regulation, while the passive components help filter out the noise and improve the power supply’s performance.
Here’s a proposed low-noise power supply design for the 24-bit ADC device:
1️⃣ Low-dropout regulator (LDO): Select a low-noise LDO with a suitable input voltage range and an output voltage that matches the 24-bit ADC device’s supply voltage requirements (2.7V to 5.3V). A popular choice is the Texas Instruments LP2985 or TPS7A47. Make sure the LDO can provide sufficient output current for your entire system, including the 24-bit ADC device and any other connected components.
2️⃣ Input capacitor: Place a ceramic capacitor (typically 1µF to 10µF) close to the LDO’s input pin to filter high-frequency noise from the input power source. Choose a capacitor with a voltage rating higher than the maximum input voltage.
3️⃣ Output capacitor: Place a ceramic capacitor (typically 1µF to 10µF) close to the LDO’s output pin to stabilise the regulator’s output and filter high-frequency noise. Choose a capacitor with a voltage rating higher than the maximum output voltage.
4️⃣ Additional filtering: For even better noise performance, you can add a ferrite bead or an LC filter between the LDO’s output and the 24-bit ADC device’s power supply pin. A ferrite bead acts as a high-frequency noise filter, while an LC filter provides more comprehensive noise filtering across a wider frequency range. The values of the inductor and capacitor in the LC filter should be chosen based on the specific noise frequencies you wish to attenuate.
5️⃣ Bypass capacitor: Place a small ceramic capacitor (typically 100nF) close to the 24-bit ADC device’s power supply pin to further suppress high-frequency noise. This capacitor acts as a local energy reservoir to provide a fast transient response.
➕1️⃣ PCB layout: Minimize trace lengths and keep the LDO, capacitors, and 24-bit ADC device as close together as possible to reduce parasitic inductance and capacitance. Use a solid ground plane and avoid ground loops to minimise noise coupling.
With this low-noise power supply design, you can provide clean and stable power to the 24-bit ADC device, ensuring high-performance and accurate measurements from the ADC.