AD7821 Analog Devices, AD7821 Datasheet - Page 13

• Manufacturer Part Number: AD7821
• Manufacturer: Analog Devices

Specifications of AD7821

• Resolution (bits): 8bit
• # Chan: 1
• Sample Rate: 1MSPS
• Interface: Par
• Analog Input Type: SE-Bip,SE-Uni
• Ain Range: Bip (Vref),Uni (Vref)
• Adc Architecture: Pipelined
• Pkg Type: DIP,LCC,SOIC

REV. B
SIMULTANEOUS SAMPLING ADC
The AD7821’s inherent track-and-hold and well defined sampling
instant makes it useful in such applications as sonar, where a num-
ber of input channels are required to be sampled simultaneously.
Figure 22 shows a circuit for such an application.
Figure 21. 16-Channel Telecom ADC System
S
–13–
The actual sampling instant at which V
approximately 50 ns after the falling edge of WR or RD in the
WR-RD or RD modes, respectively, due to internal logic delays.
However, the internal logic delay and, therefore, the sampling
instant can vary from device to device, but is typically within ±5 ns.
This means that a maximum common input sine wave of ± 2.5 V
at 32 kHz, applied to any number of AD7821s in the circuit of
Figure 22, will yield a maximum difference between the converter
outputs of typically ± 1/4 LSB.
Figure 22. Simultaneous Sampling ADCs
IN
is measured occurs
AD7821