Datasheet

LTC2977
91
2977fa
For more information www.linear.com/LTC2977
APPLICATIONS INFORMATION
Figure 32. Suggested Screen Pattern for Die Attach Pad
Figure 33. Connecting Unused Inputs to GND
2977 F32
QFN PACKAGE
APERATURE DESIGN 50% TO 80% REDUCTION GROUND PLANE
100k
100k
V
SENSEP
V
SENSEM
LTC2977
2977 F33
PC Board Layout
Mechanical stress on a PC board and soldering-induced
stress can cause the LTC2977’s reference voltage and
voltage drift to shift. A simple way to reduce these stress-
related shifts is to mount the IC near the short edge of the
PC board, or in a corner. The board edge acts as a stress
boundary, or a region where the flexure of the board is
minimal.
Unused ADC Sense Inputs
Connect all unused ADC sense inputs (V
SENSEPn
or
V
SENSEMn
) to GND. In a system where the inputs are
connected to removable cards and may be left floating
in certain situations, connect the inputs to GND using
100k resistors. Place the 100k resistors before any filter
components, as shown in Figure 33, to prevent loading
of the filter.