IC Peripherals

When protecting against electrostatic discharge (ESD), a sensitive electronic component (Load) is safeguarded by a parallel discharge path (VDR), which becomes conductive when the breakdown voltage of the protective element (VDR) is reached. In this way, the overvoltage (Transient) does not reach the sensitive load (Load), which would exceed the threshold for system failure, but is instead "clamped" to the clamping voltage.

The various data transmission standards such as RS232, CAN, USB, Ethernet, etc., operate at different frequencies and data rates. The table shows the recommended capacitance values for ESD protection for each.

When selecting suitable PCB ferrites, the online simulation platform RedExpert from Würth Elektronik can assist. RedExpert is capable of calculating the impedance required for your application based on frequency, DC bias, system impedance, and required attenuation.

If your application experiences high peak currents, you should use a ferrite from the Multilayer Power Suppression Beads series with very low Rdc and a rated current of up to 10.5 A.

When filtering signals on data transmission lines, the impedance behavior of SMT ferrites over frequency must be considered to attenuate the occurring disturbances and not the useful signal.

The frequency/impedance diagram shows the self-resonant frequencies of the MLCC capacitor types with 100 nF, 10 nF, and 1 nF. The self-resonant frequencies increase as the  capacitances decrease.

The capacitance of a capacitor is typically also dependent on an applied direct current voltage (DC Bias) and can become significantly lower with increasing voltage. From the DC Bias/capacitance diagram, it is clearly visible that with increasing miniaturization of the component, the nominal value of 470 nF decreases (red curve).

For applications with high mechanical stress, it is advisable to use soft termination capacitors. These have a termination with Ag-polymer/Ni/Si and minimize the risk of cracks occurring.

Capacitors should maintain their capacitance as consistently as possible across temperature variations. Three of the materials used, NP0, X7R, and X5R, fulfill this requirement significantly better than Y5V, as can be clearly seen in the diagram. NP0 shows virtually no changes in capacitance over a wide operating temperature range.

A typical oscillator circuit consists of the crystal oscillator and the two load capacitors C1 and C2. To determine the capacitive load, the stray capacitance of the PCB and the IC pins must also be considered.

Considerations for the layout of an oscillator circuit: The ground plane should be under the crystal and connected to its casing. Do not place vias on the trace to the crystal. Critical signals should be placed as far away as possible from the oscillator circuit.

The power modules from the MagI3C series are available as DC/DC converters with fixed or variable output voltage or as LED drivers. The DC/DC converters with integrated voltage regulator IC, power inductance, and sometimes capacitors can be implemented with a maximum of 7 design stages.

The self-heating of the inductor depends on the layout and the environment. Wider traces and greater copper thickness increase the flow of heat dissipated by the inductance. This allows the inductance to be operated with higher currents. The datasheet explains the specific measurement conditions.