SAPHBCTL.
EXCBIAS
SAPHBCTL.
PGABIAS
TxBias
0
1
SAPHBCTL.
CH0EBSW
SAPHMCNF.LPBE
from ASQ
TxBias
SAPHBCTL.
PGABSW
from ASQ
RxBias
to
SDHS
SDHSCTL6.
PGA_GAIN[5:0]
from
ASQ
SAPHICTL.
MUXCTL
SAPHICTL.
MUXSEL
1
0
TxBias
RxBias
SAPHICTL.
DUMEN
ASQ_acquisition
ASQ_adc_arming
SDHS_adc_arming
SDHS_acquisition
SAPHBCTL.CPDA
Charge
Pump
en
PGA
CH1_IN
CH0_IN
Tx
Bias
PPG or
PPG_A
ASQ
PHY
PVSS
PVCC
CH1_OUT
CH0_OUT
TR0
TR1
0
0
1
1
from ASQ
SAPHBCTL.
ASQBSW
0
1
from ASQ
0
0
1
1
SAPHMCNF.LPBE
SAPHBCTL.
ASQBSW
SAPHBCTL.
CH1EBSW
from ASQ
0
1
from ASQ
0
0
1
1
SAPHMCNF.LPBE
SAPHBCTL.
ASQBSW
0
1
0
0
1
1
from
ASQ
SAPHMCNF.LPBE
SAPHMCNF.
BIMP
Rx
Bias
SAPHMCNF.
BIMP
Ground centric signal
TxBias centric signal
RxBias centric signal
PVcc/4 centric signal
PVcc/2 centric signal
PVcc/4 + Bias centric
Dummy
Input
SAPHMCNF.CPEO
Physical Interface (PHY) Block
508
SLAU367P – October 2012 – Revised April 2020
Copyright © 2012–2020, Texas Instruments Incorporated
Sequencer for Acquisition, Programmable Pulse Generator, and Physical
Interface (SAPH, SAPH_A)
NOTE: Excitation pulses are driven on CH0_OUT, and CH0_IN is connected to the PGA dummy input.
Figure 21-15. Excitation
3. Wait for almost the complete estimated time of flight (TOF) between the transducer 0 (TR0) and the
transducer 1 (TR1). The delay must be less than TOF to capture the beginning of the arriving pulse
train.
4. Before the signal arrives at the transducer 1 (TR1), power on the SDHS ADC so that the SDHS is fully
settled before sampling data.
5. Before the signal arrives at the transducer 1 (TR1), apply the Rx bias to CH1_IN while CH1_OUT is
connected to GND through the SWG1 switch (see
and