LTC2225 LINER [Linear Technology], LTC2225 Datasheet - Page 15

• Manufacturer Part Number: LTC2225
• Description: 12-Bit, 10Msps Low Power 3V ADC
• Manufacturer: LINER [Linear Technology]

APPLICATIO S I FOR ATIO
and nap modes, all digital outputs are disabled and enter
the Hi-Z state.
Grounding and Bypassing
The LTC2225 requires a printed circuit board with a clean,
unbroken ground plane. A multilayer board with an inter-
nal ground plane is recommended. Layout for the printed
circuit board should ensure that digital and analog signal
lines are separated as much as possible. In particular, care
should be taken not to run any digital track alongside an
analog signal track or underneath the ADC.
High quality ceramic bypass capacitors should be used at
the V
tors must be located as close to the pins as possible. Of
particular importance is the 0.1µF capacitor between
REFH and REFL. This capacitor should be placed as close
to the device as possible (1.5mm or less). A size 0402
ceramic capacitor is recommended. The large 2.2µF
DD
, OV
DD
, V
CM
, REFH, and REFL pins. Bypass capaci-
U
U
W
U
capacitor between REFH and REFL can be somewhat
further away. The traces connecting the pins and bypass
capacitors must be kept short and should be made as wide
as possible.
The LTC2225 differential inputs should run parallel and
close to each other. The input traces should be as short as
possible to minimize capacitance and to minimize noise
pickup.
Heat Transfer
Most of the heat generated by the LTC2225 is transferred
from the die through the bottom-side exposed pad and
package leads onto the printed circuit board. For good
electrical and thermal performance, the exposed pad
should be soldered to a large grounded pad on the PC
board. It is critical that all ground pins are connected to a
ground plane of sufficient area.
LTC2225
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