9 Power Supply Recommendations
The LDC3114 power supply should be bypassed with a 1-µF and a 0.1-µF pair of capacitors in parallel to
ground. The capacitors should be placed as close to the LDC as possible. The smaller value 0.1-µF capacitor
should be placed closer to the VDD pin than the 1-µF capacitor. The capacitors should be a low-ESL, low-ESR
type.
Refer to
Recommended Operating Conditions
for more details.
10 Layout
10.1 Layout Guidelines
The COM pin must be bypassed to ground with an appropriate value capacitor. For details of how to choose the
capacitor value, refer to
. C
COM
should be placed as close as possible to the COM
pin. The COM signal should be tied to a small copper fill placed underneath the IN
n
signals. The IN
n
signals
should stay clear of other high frequency traces.
Each active channel needs to have an LC resonator connected to the corresponding IN
n
pins. The sensor
capacitor should be placed within 10 mm of the corresponding IN
n
pin, and the inductor should be placed at the
appropriate location next to (but not touching) the metal target. The IN
n
traces should be at least 6 mil (0.15 mm)
wide to minimize parasitic inductances.
10.2 Layout Example
Figure 10-1. Layout of LDC3114 (TSSOP-16) With Decoupling Capacitors and Sensor Capacitors
SNOSDD0 – DECEMBER 2021
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