Datasheet Analog Devices AD7821TQ — 数据表

a LC2MOS High Speed, ␮P Compatible
8-Bit ADC with Track/Hold Function
AD7821 FEATURES
Fast Conversion Time: 660 ns Max
100 kHz Track-and-Hold Function
1 MHz Sample Rate
Unipolar and Bipolar Input Ranges
Ratiometric Reference Inputs
No External Clock
Extended Temperature Range Operation
Skinny 20-Lead DlPs, SOIC, and 20-Terminal
Surface-Mount Packages FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION PRODUCT HIGHLIGHTS The AD7821 is a high speed, 8-bit, sampling, analog-to-digital
converter that offers improved performance over the popular
AD7820. It offers a conversion time of 660 ns (versus 1.36 µs
for the AD7820) and 100 kHz signal bandwidth (versus 6.4
kHz). The sampling instant is better defined and occurs on the
falling edge of WR or RD. The provision of a VSS pin (Pin 19)
allows the part to operate from ± 5 V supplies and to digitize
bipolar input signals. Alternatively, for unipolar inputs, the VSS pin
can be grounded and the AD7821 will operate from a single +5 V
supply, like the AD7820. 1. Fast Conversion Time
The half-flash conversion technique, coupled with fabrication
on Analog Devices’ LC2MOS process, enables a very fast conversion time. The conversion time for the WR-RD mode is …