HV2818 from Microchip
- Braemac
- Jul 24, 2020
- 2 min read
The current ultrasound imaging market is trending towards higher image quality (IQ) and system miniaturisation. To enable an ergonomic design of high-element count (256+) probes and handheld scanners, the High Voltage (HV) Multiplexers (MUX) need higher channel integration and are often placed in the probe handle close to the sensors.
HV2818/2918 are Microchip’s next generation 32ch HV MUXes with superior performance for ultrasound applications. These devices need only a single +5V bias supply which is readily available in most systems. The use of only low voltage bias significantly reduces the dynamic power dissipation when operating the switches at a high frequency. It reduces the size of the power supply, simplifies system design, and eliminates concerns of high voltage rails into the probe that contacts human skin. Despite not needing HV bias supply, Microchip’s unique asymmetrical architecture IP utilized in HV2818/HV2918 maintains high performance, such as +/-100V signal capability, 2.7A switch-on peak current rating and 32 channels in a 9mmX9mm QFN package. The 2.53mm^2/ch channel density makes this family particularly attractive for MUX-on-probe and handheld scanner applications where space is constrained. In addition, the superior off-isolation performance enables high-quality images for medical ultrasound diagnoses.
For customers with a new design, the QFN package makes it easier to evaluate these MUXes at R&D phase whereas for existing customers, the HV2818/HV2918 are designed to be pin-to-pin compatible to previous widely adopted devices, HV2801/2901, except for bias pins. This feature enables a much faster and easier development route for customers to migrate from previous generation to the newer one.
Key features
• 32-channel (16 X 2:1 MUX) High-Voltage Analog Switch
• Only +5V Bias Supply Required
• +/-100V Peak-to-Peak Analog Signal Voltage
• 2.7A Switch-On Peak Current
• 3.3V and 5V CMOS Input Logic Level
• 66 MHz Data Shift Clock Frequency
• Low-Parasitic Capacitance and Low Harmonic Distortion
• 200 KHz to 50 MHz Large Signal Frequency
• -70 dB Typical Off Isolation at 5.0 MHz
• Excellent Noise Immunity
• Cascadable Serial Data Register with Latches
• Integrated Bleed Resistors on the SW Outputs (HV2918 only)
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