SNAS648C October 2014 – February 2023 TDC1000
PRODUCTION DATA
Single Echo mode is suitable for concentration measurements and flow metering applications. The device can be configured for Single Echo mode by setting the RECEIVE_MODE bit to 0 in the CONFIG_4 register. In Single Echo mode, the device will generate STOP pulses for every zero-cross qualified by the threshold comparator, up to the number of expected STOP events configured in the NUM_RX field in the CONFIG_1 register.
The threshold comparator qualifies the next zero-cross after an RX amplitude smaller than the programmed threshold voltage is detected. The zero-cross detector will provide output pulses corresponding to the rising edge of the received signal crossing the VCOM level, as shown in #SNAS6486370. The threshold voltage can be set in the ECHO_QUAL_THDL field in the CONFIG_3 register.
If the number of expected pulses programmed in NUM_RX is not received or the time-of-flight operation times out, the TDC1000 will indicate an error condition in the ERROR_FLAGS register and will set the ERRB pin low.