Datasheet

LTC2314-14

231414fa

For more information www.linear.com/LTC2314-14

APPLICATIONS INFORMATION

Figure 16. Top Silkscreen

Figure 17. Layer 1 Top Layer

Figure 18. Layer 2 GND Plane

capacitors are essential to the low noise operation of the

ADC. The analog input traces are screened by ground.

For more details and information refer to DC1563, the

evaluation kit for the LTC2314-14.

Bypassing Considerations

High quality tantalum and ceramic bypass capacitors

should be used at the V

, OV

and REF pins. For opti-

mum performance, a 2.2µF ceramic chip capacitor should

used for the V

and OV

pins. The recommended

bypassing for the REF pin is also a low ESR, 2.2µF ceramic

capacitor. The traces connecting the pins and the bypass

capacitors must be kept as short as possible and should

be made as wide as possible avoiding the use of vias.

The following is an example of a recommended PCB layout.

All analog circuitry grounds should be terminated at the

LTC2314-14. The ground return from the LTC2314-14 to

the power supply should be low impedance for noise free

operation. Digital circuitry grounds must be connected to

the digital supply common.

In applications where the ADC data outputs and control

signals are connected to a continuously active micropro

cessor bus, it is possible to get errors in the conversion

results.

These errors are due to feed-through from the

microprocessor

to the successive approximation com-

parator. The

problem can be eliminated by forcing the

microprocessor

into a “Wait” state during conversion or

by using three-state buffers to isolate the ADC data bus.