The AD570 is an 8-bit successive approximation A/D converter
consisting of a DAC, voltage reference, clock, comparator, successive
approximation register and output buffers—all fabricated
on a single chip. No external components are required to perform
a full accuracy 8-bit conversion in 25 ms.
The AD570 incorporates the most advanced integrated circuit
design and processing technology available today. I2L (integrated
injection logic) processing in the fabrication of the SAR
function along with laser trimming of the high stability SiCr
thin-film resistor ladder network at the wafer stage (LWT) and a
temperature compensated, subsurface Zener reference insures
full 8-bit accuracy at low cost.
Operating on supplies of +5 V and –15 V, the AD570 accepts
analog inputs of 0 V to +10 V unipolar of ±5 V bipolar, externally
selectable. As the BLANK and CONVERT input is driven
low, the three-state outputs go into the high impedance state
and a conversion commences. Upon completion of the conversion,
the DATA READY line goes low and the data appears at
the output. Pulling the BLANK and CONVERT input high
three states the outputs and readies the device for the next conversion.
The AD570 executes a true 8-bit conversion with no
missing codes in approximately 25 ms.
The AD570 is available in two version; the AD570J is specified
for the 0°C to +70°C temperature range, the AD570S for –55°C
to +125°C. Both guarantee full 8-bit accuracy and no missing
codes over their respective temperature ranges.