Application Design Center - Medical Imaging Devices
Circuit Protection of Transducer Input
Solutions
Design Notes:
- Protection Application:
- The sensor input provides an interface between the patient and the measurement circuits. The electrical threat will be ESD.
- Solution Description:
- As shown at the left, a single multilayer varistor can be used to protect the sensor input.
- Companion Solutions:
- For applications with multiple transducer and sensor circuits, the SP7x series of rail clamp arrays can be used.
- Regulatory Issues:
- The IEC 61000-4-2 will be the most appropriate standard that applies for this circuit. It supplies a test method for verifying that the end product is not susceptible to ESD events.
- Unique Features:
- Does not apply.
- Application Warnings:
- The signal frequency of the transducer input should be taken into account. For frequencies greater than 150MHz, the PulseGuard technology should be considered.
