Dear TI-Team!
I've some experience with LDC1000 and have ordered the new LDC1101 now. Studying the datasheet, the following questions came up:
ad 1 Features: What is meant with "Remote Sensor Placement Isolating the LDC from Harsh Environments". Is this a new "Feature" in comparison to LDC1000?
ad 3 Description: "Inductive sensing Technology enables precise measurement of....": If the same tank-configuration is used and the same external clock frequency is used: Is the LDC1000 accurracy for L-measurment (24bit) the same to LDC1101 accurracy in LHR mode? Or does the new LDC1101 incorporate new design features that improve accurracy and resolution? And same question for RP-resolution and accurracy...
ad 8.4.1 Measurement Modes: "Both measurment subsystems can convert simultaneously but at different sample intervals - the completion... is asynchronous...": Is it possible to gather data from both subsystems querying RPL and then LHR at "High Speed" without reconfiguring the chip to the other mode, so that no sleep mode cycle is needed?
What can be done, to get RP with 16BIT AND fres with 24 Bit as with LDC1000?
ad 8.4.4 Reference Count Setting: Are the given values 8,6µs to 87,38ms correct?
The formula for Measurment Time (tconv)=(RCOUNT*16+55)/fclkin. RCOUNT ranges from 512 to 65535 (right?). fclkin max is 16MHz. So tconvmin=515µs and tconvmax=65,5ms...
What is wrong here?
8.6.24 Register LHR_RCOUNT_MSB...: Table 26: Description: Valid range: 2<= RCOUNT[15:8]<=65535. Is this correct?
Shouldn't it say 2<=RCOUNT[15:8]<=255 or so?
8.6.25 and 8.6.26: the LHR_OFFSET_LSB and LHR_OFFSET_MSB Fields: The LHR_OFFSET Register(s) should be set by the user , but there is no description anywhere, what the purpose of these registers is. They are only used in formula 11, but what is their purpose and how should they be set?
8.6.28 Table 30: LHR_DATA_LSB Field Descriptions: Is the formula given for fsensor correct? If yes, how is it related to formula 11?
9.1.9 LHR Sample Rate Configuration with RCOUNT:
What is "really" meant with ENOB (Effecibe number of bits?). It is introduced here without giving a context: is it introduced to be able to calculate the effective resolution with ENOB?
If yes, how can I calculate it?
9.2.3: Application Courves: how can I calculate such courves for my specific application (simple distance measurment)
I thought to understand that LHR Resulution is: 1/(RCOUNT*16) at Target Distance /Sensor Diameter =1. This is true for the black courve. But for the red courve it is not. Can you give the calculus for that? What is the calculus for values <1? (i took one example of your application courve in 9.2.3).
Looking forward to your reply!
Franz