Application Design Center - Portable Navigation Device
Circuit Protection of Headphone Port
Solutions
Design Notes:
- Protection Application:
- For these audio lines, the maximum signal values may be 12 Vp-p, and operate at frequencies less than 30kHz. At this frequency, the capacitance of the suppressor does not need to be taken into account. The electrical threat is ESD.
- Solution Description:
- As shown at the left, discrete multilayer varistors can be used for layout flexibility. Due to the analog nature of the audio signals, uni-polar TVS diode arrays are recommended only if the negative part of this signal is -0.5V or less since they may clip the negative part of the audio signal if the magnitude is larger.
- Companion Solutions:
- Other solutions within the Littelfuse MLV portfolio exist in addition to these recommendations. For example, if the manufacturing process cannot handle 0402-size components, devices with the same characteristics can be found in 0603-size.
- Regulatory Issues:
- The IEC 61000-4-2 will be the most appropriate standard that applies for this port. It supplies a test method for verifying that the end product is not susceptible to ESD events.
- Unique Features:
- Does not apply.
- Application Warnings:
- Does not apply.
