Datasheet

Measurement Core
IDRIVE
IN0A
IN0B
Sensor 0
Chan 0
Driver
IN1A
IN1B
Sensor 1
Chan 1
Driver
IN2A
IN2B
Sensor 2
Chan 2
Driver
IN3A
IN3B
Sensor 3
Chan 3
Driver
Sensor Amplitude
Full Current Activation
settle time
Low Power Activation settle
time
Time
41
LDC1612
,
LDC1614
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SNOSCY9A DECEMBER 2014REVISED MARCH 2018
Product Folder Links: LDC1612 LDC1614
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Figure 55. Sensor Full Current Activation vs. Low Power Activation
8.1.5 Sensor Current Drive Configuration
The registers listed in Table 41 are used to control the sensor drive current so that the sensor signal amplitude is
within the optimum range of 1.2 V
P
to 1.8 V
P
(sensor amplitudes outside this optimum range can be reported in
the status register - refer to Device Status Registers ). The device can still convert with sensor amplitudes lower
than 0.6 V
P
, however the conversion noise will increase with lower sensor amplitudes. Below 0.6 V
P
the sensor
oscillations may not be stable or may completely stop and the LDC will stop converting. If the current drive
results in the oscillation amplitude greater than 1.8 V, the internal ESD clamping circuit will become active. This
may cause the sensor frequency to shift so that the output values no longer represent a valid system state.
Figure 56 shows the block diagram of the sensor driver. Each channel has an independent setting for the IDRIVE
current used to set the sensor oscillation amplitude.
Figure 56. LDC1614 Sensor Driver Block Diagram