Time-to-Digital-Converters by Acam
Home Acam TDC PICOSTRAIN® PICOCAP® PICOTURN® Quote Sales & Support
spacer
Acam TDC

Time to Digital Converters
TDC - GP1
TDC - GP2
TDC - GPX
Time-to-Digital Applications
spacer
PICOSTRAIN®

Time to Digital Converters for Digital Strain Gage
PICOSTRAIN® PS08
PICOSTRAIN® PS081
PICOSTRAIN® PS021
Strain Gage Applications
spacer
PICOCAP®

Time to Digital Converters for Capacitance Measurement
PICOCAP® PS021
PICOCAP® PSA21
Capacitance Applications
spacer
PICOTURN®

Time to Digital Converters for Speed Sensors
PICOTURN® 2G
PICOTURN® BM/SM
Speed Sensor Applications
spacer

Time-to-Digital - TDC Cookbook

spacerApplications for
time-to-digital converters
TDC - Cookbook
spacer

Acam USA Newsletter

Newsletter Sign Up privacy

PS021 - Averaging and Noise

Precision of a Single Measurement

 

The precision of a single measurement (AVRate = 1) depends on 2 parameters:

  • The measurement range
  • The discharge time

As long as the update rate is not higher than 5 kHz we recommend working with measurement range 2. Setting the discharge time to 50 -100 µs, PSØ21 has the performance shown in the table on the right.

Internal Averaging

PSØ21 internally improves the precision of the measurement results by averaging. The measuring principle guarantees that no significant systematic errors affect the result. The standard deviation is improved by the square root of the averaging rate.

 

 
PS021 Circuits

PS021 Averaging Chart
spacer

PS021 - Temperature Measurement

Temperature Measurement

The K-factor of strain gages depends on temperature and decreases with higher temperature. If the temperature of the strain gage is known, it is easy to correct for the main failure (active temperature compensation).

PSØ21 o-ffers the option of temperature measurement with an external temperature sensitive resistor.

Basically the temperature measurement is nothing more than a simplified SG measurement at separate ports. A measurement takes 2 discharge/recharge cycles and is done once per measurement sequence.

In the first cycle the capacitor is discharged through the temperature sensitive resistor. The nominal value of the resistance should be minimum 500 Ohm. In the second cycle the capacitor is discharged through a temperature stable reference resistor.

PS021 temperature measurement

External circuit of the temperature port

spacer
 
 
spacer