MICROCHIP HV2918/R4X

The HV2818/HV2918 are low harmonic distortion, low charge injection, 16 2:1 multiplexer/demultiplexer, high -voltage analog switches without high-voltage bias supplies. They are intended for use in applications requiring high-voltage switching controlled by lowvoltage control signals, such as medical ultrasound imaging, driving piezoelectric transducers and printers. The HV2818/HV2918 are pin-to-pin compatible to high-voltage bias HV2801/HV2901, except for bias voltage pins. HV2818/HV2918 are available in a 64-pin, 9×9 mm QFN package. HV2818/HV2918 have asymmetric topology to implement a small size in low voltage bias high-voltage switches while keeping performance such as peak current. The SW pin can pass high-voltage pulsed signals when the switch is ON. During the OFF state, high-voltage should not be applied to the SW pin due to its asymmetric topology. In medical ultrasound systems, the Y pin should be connected to the AFE (analog front end) and the SW pin should be connected to a single piezoelectric transducer element to avoid high-voltage in the SW pin during the switch OFF state. HV2818 and HV2918 are identical, except for bleed resistors at SW pins. HV2818 does not have the bleed resistors at SW pins like HV2801. HV2918 has the bleed resistors at SW pins like HV2901. The bleed resistors eliminate possible voltage build-up on capacitive loads such as piezoelectric transducers. The ON/OFF state of the 32 switches is programmed individually through a digital serial interface. The devices only need a +5V low voltage bias supply. However, all of the analog switches can pass up to ±100V high-voltage pulsed signals. Like other low voltage bias switches, the HV2818/HV2918 cannot pass high-voltage DC signals. They can only pass high -voltage pulsed signals up to 2.5 μs pulse width. These devices have typical 6Ω ON resistance and 50 MHz bandwidth for small signals.

• 32-channel (16 2:1 MUX) High-Voltage Analog Switch
• Only +5V Bias Supply Required
• 3.3V and 5V CMOS Input Logic Level
• Asymmetric Switch Topology for Small Size
• 66 MHz Data Shift Clock Frequency
• Low-Parasitic Capacitance
• Low Harmonic Distortion
• DC to 50 MHz Analog Small-Signal Frequency
• 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)

• Medical Ultrasound Imaging
• Non-Destructive Testing (NDT) Metal Flaw Detection
• Piezoelectric Transducer Drivers
• Inkjet Printer Head
• Optical MEMS Modules