AD7864 Analog Devices, AD7864 Datasheet - Page 26

• Manufacturer Part Number: AD7864
• Description: High Speed, Low Power, 4-channel Simultaneous Sampling, 12-Bit ADC
• Manufacturer: Analog Devices

Specifications of AD7864

• Resolution (bits): 12bit
• # Chan: 4
• Sample Rate: 520kSPS
• Interface: Par
• Analog Input Type: SE-Bip,SE-Uni
• Ain Range: Bip 10V,Bip 2.5V,Bip 5.0V,Uni 2.5V,Uni 5.0V
• Adc Architecture: SAR
• Pkg Type: QFP

AD7864
MULTIPLE AD7864S IN A SYSTEM
Figure 27 shows a system where a number of AD7864s are
configured to handle multiple input channels. This type of
configuration is common in applications such as sonar and
radar. The AD7864 is specified with maximum limits on
aperture delay match. This means that the user knows the
difference in the sampling instant between all channels. This
allows the user to maintain relative phase information between
REF193
5MHz
Figure 27. Multiple AD7864s in Multichannel System
V
V
V
V
V
CLKIN
V
V
V
V
V
CLKIN
IN1
IN2
IN3
IN4
REF
IN1
IN2
IN3
IN4
REF
AD7864
AD7864
Rev. D | Page 26 of 28
EOC
CS
RD
RD
CS
12
12
the different channels. The AD7864 has a maximum aperture
delay matching of 4 ns.
All AD7864s use the same external SAR clock (5 MHz).
Therefore, the conversion time for all devices is identical;
consequently, all devices can be read simultaneously. In the
example shown in Figure 27, the data outputs of two AD7864s
are enabled onto a 32-bit wide data bus when EOC goes low.
32
RD
ADSP-2106x
ADDRESS
DECODE