The PGA460 device is a highly-integrated system on-chip ultrasonic transducer driver and signal conditioner with an advanced DSP core. The device has a complimentary low-side driver pair that can drive a transducer either in a transformer based topology using a step-up transformer or in a direct-drive topology using external high-side FETs. The device can receive and condition the reflected echo signal for reliable object detection. This feature is accomplished using an analog front-end (AFE) consisting of a low-noise amplifier followed by a programmable time-varying gain stage feeding into an ADC. The digitized signal is processed in the DSP core for both near-field and far-field object detection using time-varying thresholds.
The main communication with an external controller is achieved by either a time-command interface (TCI) or a one-wire USART asynchronous interface on the IO pin, or a CMOS-level USART interface on the RXD and TXD pins. The PGA460 can be put in ultra-low quiescent current low-power mode to reduce power consumption when not in use and can be woken up by commands on the communication interfaces.
The PGA460 also includes on-chip system diagnostics which monitor transducer voltage during burst, frequency and decay time of transducer to provide information about the integrity of the excitation as well as supply-side and transceiver-side diagnostics for overvoltage, undervoltage, overcurrent and short-circuit scenarios.