2 s ADC with T/H
+5 Volt Operation
4 s Voltage Output DAC
Fast Bus Access Time—75 ns
Digitally Controlled Calibration
Process Control Equipment
8-Bit, 4-Channel Data
FUNCTIONAL BLOCK DIAGRAM
A0 A1 VDD (+5.0V)
DGND RD CLK CS WR DATA I/O
The AD8401 is a complete data acquisition and control system
containing ADC, DAC, 4-channel MUX, and internal voltage
reference. Built using CBCMOS, this monolithic circuit offers
the user a complete system with very high package density and
The converter is a successive approximation ADC with T/H,
and is capable of operating with conversion times as short as
2 µs. Analog input bandwidth is 200 kHz, and DAC output volt-
age settling time is less than 4 µs, making the AD8401 capable
of controlling servo loops with speed and precision.
The 8-bit data interface provides both read and write operation
for parallel bus interfaces to microcontrollers and DSP proces-
sors. An external 5 MHz clock sets the 2 µs conversion rate.
Slower clocks reduce the conversion time and the internal power
dissipation. The standard control lines: Reset, Busy, Interrupt,
Read and Write complete the handshaking signals for micro-
processor communication. A start trigger ST input allows pre-
cise sampling intervals in synchronous sampling applications.
The input multiplexer addressing is designed for direct interface
to the AD899 hard-disk drive, read-channel device with no extra
hardware or special software. Analog input range levels are like-
wise compatible with the AD899.
The AD8401 is designed to operate from a single +5 volt sup-
ply, which will give an ADC input range of 0 V to 3.0 V, and
DAC output range of 0 V to 2.5 V.
The AD8401 is offered in the SOIC-28 surface mount package,
and is guaranteed to operate over the extended industrial tem-
perature range of –40°C to +85°C.
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.