Datasheet

AD8366
Rev. A | Page 17 of 28
APPLICATIONS INFORMATION
BASIC CONNECTIONS
Figure 50 shows the basic connections for operating the AD8366.
A voltage from 4.75 V to 5.25 V should be applied to the supply
pins. Each supply pin should be decoupled with at least one low
inductance, surface-mount ceramic capacitor of 0.1 µF placed as
close as possible to the device.
The differential input impedance is 200 Ω and sits at a nominal
common-mode voltage of V
POS
/2. The inputs can be dc-coupled
or ac-coupled. If using direct dc coupling, the common-mode
voltage, V
CM
, can range from 1.5 V to V
POS
/2.
The output buffers of the AD8366 are low impedance around
25 Ω designed to drive ADC inputs. The output common-mode
voltage defaults to V
POS
/2; however, it can be adjusted by applying a
desired external voltage to VCMA/VCMB. The common-mode
voltage can be adjusted from 1.6 V to 3.0 V without significant
harmonic distortion degradation.
To enable the AD8366, the ENBL pin must be pulled high. Taking
ENBL low disables the device, reducing current consumption to
approximately 3 mA at ambient temperature.
VPSIA
IPPA
IPMA
ENBL
ICOM
IPMB
IPPB
VPSIB
BIT0/CS
BIT1/SDAT
BIT2/SCLK
BIT3
OCOM
BIT4
BIT5
DENA
D
ECB
OFSB
CCMB
VCMB
VPSOB
OPPB
OPMB
DENB
DECA
OFSA
CCM
A
VCMA
VPSOA
O
PPA
OPMA
SENB
VPOS
AD8366
VPOS
0.01µF
0.01µF
0.01µF
8200pF
8200pF
0.01µF
0.01µF
0.01µF
0.01µF
VPOS
0.1µF 0.1µF
VPOS
0.1µF 0.1µF
VPOS
0.1µF 0.1µF
PARALLEL/SERIAL
CONTROL INTERFACE (PCI)
CHANNEL A
OUTPUT
CHANNEL B
OUTPUT
CHANNEL A
INPUT
CHANNEL B
INPUT
07584-046
Figure 50. Basic Connections