LTC2309 Linear Technology Corporation, LTC2309 Datasheet - Page 18

• Manufacturer Part Number: LTC2309
• Description: 12-Bit SAR ADC
• Manufacturer: Linear Technology Corporation

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LTC2309
Board Layout and Bypassing
To obtain the best performance, a printed circuit board with
a solid ground plane is required. Layout for the printed
board should ensure digital and analog signal lines are
separated as much as possible. Care should be taken not
to run any digital signals alongside an analog signal. All
analog inputs should be shielded by GND. V
APPLICATIONS INFORMATION
18
Figure 14. Bipolar Transfer Characteristics (2’s Complement)
011...111
011...110
000...001
000...000
111...111
111...110
100...001
100...000
–FS/2
INPUT VOLTAGE (V)
BIPOLAR
LSB
–1
ZERO
0V
LSB
1
FS = 4.096V
1LSB = FS/2
1LSB = 1mV
FS/2 – 1LSB
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REF
, REFCOMP
Figure 16. Suggested Layout
and AV
close to the pin as possible. Maintaining a low impedance
path for the common return of these bypass capacitors
is essential to the low noise operation of the ADC. These
traces should be as wide as possible. See Figure 16 for a
suggested layout.
Figure 15. Unipolar Transfer Characteristics (Straight Binary)
111...111
111...110
100...001
100...000
011...111
011...110
000...001
000...000
DD
should be bypassed to the ground plane as
UNIPOLAR
0V
ZERO
INPUT VOLTAGE (V)
FS = 4.096V
1LSB = FS/2
1LSB = 1mV
FS – 1LSB
2309 F15
12
2309f