TDC1000-TDC7200EVM: TDC1000-TDC7200EVM

manikanta kolisetty

Part Number: TDC1000-TDC7200EVM
Other Parts Discussed in Thread: TDC1000, TDC7200

Respected sir,

I want to test Accuracy TDC1000-TDC7200EVM for flow meter application for this requirement I have studied about the TDC-1000 (AFE ) and TDC-7200(Stop watch Timer) Data sheets.

While studying this TDC-1000 (AFE ) and TDC-7200(Stop watch Timer) Data sheets, I got a some doughts Please clarify my Doughts regarding this Topic.

TDC-1000 (AFE ):

1.what happened if number of transmitted pulses are increased from 5 to 10 pulses ?

2.what happened if number of Stop pulses are increased from 2 to 5 pulses?

3.what happened if Threshold voltage (ECHO_QUAL_THLD) is changed from minimum to maximum ?

4.what happened if the LNA is enabled and LNA is disabled ?

5.what happened if the PGA gain is enabled and PGA gain is disabled ?

6.what happened if the Damping is enabled and Damping is disabled?

7.what happened if transmitting pulse position shifting (TX_PH_SHIFT_POS) is changed from minimum to maximum ?

8.When Short TOF measurement is used And Standard TOF measurement is Used ?

9 what happened if the sensor interfacing circuit is not used between the ultrasonic sensor and TDC-1000 (AFE ) ?

TDC-7200(Stop watch Timer):

1.what happened if the calibration value is changed from 10 to 40 clock cycles ?

2.What happened if the force calibration is not happened per every measurement (Difference between Calibration is not performed after interrupted measurement and Calibration is always performed at the end )?

Please Give Reply As soon as possible.

Thanking you sir.

Regards,

K.manikanta.

over 8 years ago

0 Scott Cummins over 8 years ago

TI__Mastermind 31655 points

Hello,

TDC1000

1. Changing the number of pulses will affect the strength of the ultrasonic signal coming from the transducer. More pulses means greater acoustic energy up until the point where the transducer becomes saturated.

2. The device will detect 5 return echoes instead of 2.

3. Please see the following datasheet section: 8.3.6.1 Threshold Detector and DAC

4. and 5. From section 8.3.2 Receiver Signal Path in the datasheet

"The RX signal path consists of a channel selection multiplexer followed by an LNA. The output of the LNA can
then be sent to the PGA for additional amplification if needed. Finally, the signal is fed into a set of comparators
which generate pulses on the STOP pin based on the programmed threshold levels. The block diagram for the
receiver path can be seen in Figure 15.
If the 20-dB to 41-dB of gain provided by the TDC1000 is insufficient, additional gain can be added prior to the
COMPIN pin. Likewise, with a strong received signal, if the gain from the LNA or PGA is not be needed, they can
be bypassed and the transducer signal could be directly connected to the COMPIN pin"

6. Please see the following datasheet section: 8.4.3.3 Transmitter Damping

7. Please see the following datasheet section: 8.4.3.2 TX 180° Pulse Shift

8. Short TOF is necessary when the total TOF is shorter than the common mode settling time and the minimum autozero period time. Using Short TOF mode switches those periods to be before the START pulse is generated instead of after. Please see the following datasheet section: 8.4.6 Time-of-Flight (TOF) Control

9. The device will work fine. The sensor interface board just provides a more efficient excitation of the transducers. See the following app note: www.ti.com/.../snaa284a.pdf

TDC7200

1. A larger number of calibration measurements will result in a more accurate calibration, but takes more time. Please see the following datasheet section: 8.4.1 Calibration

2. You just described what will happen in your question.

Regards,

Sensors

Sensors forum

TDC1000-TDC7200EVM: TDC1000-TDC7200EVM