When the LDC sequences through the channels in multi-channel mode, the dwell time interval for each channel is the sum of 3 parts: sensor activation time + conversion time + channel switch delay.
The sensor activation time is the amount of settling time required for the sensor oscillation amplitude to stabilize, as shown in Figure 49. The settling wait time is programmable and should be set to a value that is long enough to allow stable oscillation. The settling wait time for channel x is given by:
Table 37 illustrates the registers and values for configuring the settling time for each channel.
|0||SETTLECOUNT0, addr 0x10||SETTLECOUNT0 ['15:0]||(SETTLECOUNT0×16)/fREF0|
|1||SETTLECOUNT1, addr 0x11||SETTLECOUNT1 [15:0]||(SETTLECOUNT1×16)/fREF1|
|2||SETTLECOUNT2, addr 0x12||SETTLECOUNT2 [15:0]||(SETTLECOUNT2×16)/fREF2|
|3||SETTLECOUNT3, addr 0x13||SETTLECOUNT3 [15:0]||(SETTLECOUNT3×16)/fREF3|
The SETTLECOUNTx for any channel x must satisfy:
Round the result to the next highest integer (for example, if Equation 10 recommends a minimum value of 6.08, program the register to 7 or higher).
L, RP and C values can be obtained by using Texas Instrument’s WEBENCH® for the coil design.