Datasheet
LTC2389-18
34
238918f
applicaTions inFormaTion
Partial Top Silkscreen
238918 F21
BOARD LAYOUT
To obtain the best performance from the LTC2389-18, a
printed circuit board (PCB) is recommended. Layout for
the printed circuit board should ensure the digital and
analog signal lines are separated as much as possible. In
particular, care should be taken not to run any digital clocks
or signals alongside analog signals or underneath the ADC.
Pin Compatibility with LTC238x-16
To ensure a board layout intended for use with the
LTC2389-18 is also compatible with 16-bit versions of the
LTC238x family, the design should maintain the ability to
drive Pins 5 (MODE1) and 7 (DO/AO) to logic low levels,
to drive Pin 4 (MODE0) to both logic high and logic low
levels, and to dynamically drive Pin 8 (D1/A1) to both
logic high and logic low levels. Simplifications to these
constraints are possible based on the specific application.
For further details on the operation of LTC238x-16 devices,
please refer the associated data sheets.
Recommended Layout
The following is an example of a recommended PCB layout.
A single solid ground plane is used. Bypass capacitors to
the supplies are placed as close as possible to the supply
pins. Low impedance common returns for these bypass
capacitors
are essential to the low noise operation of the
ADC.
The analog input traces are shielded by ground. For
more details and information refer to DC1826A-A, the
evaluation kit for the LTC2389-18.