SP574B Datasheet, PDF (10/15 Pages) Sipex Corporation – 12-Bit Sampling A/D Converters

A₀ may be toggled without damage to the con-
verter at any time. Break–before–make action is
guaranteed between the two data bytes. This as-
sures that the outputs which are strapped together
in Figure 5 will never be enabled at the same time.
In Figure 7, it can be seen that a read operation
usually begins after the conversion is complete and
STS is low. If earlier access is needed, the read can
begin no later than the addition of times t and t
DD
HS
before STS goes low.
"NYQUIST" SAMPLING
Each of the SPx74B analog-to-digital convert-
ers has been designed to provide Nyquist sam-
pling (highest input frequency is 1/2 of the
sampling rate) data conversion with no degra-
dation in DC performance. This is shown in
Figure 10. Note that the Differential Linearity
and Integral Linearity min/max values are well
within the ± 1/2 LSB limits of a K-version
Converter. Also, the Typical FFT at Nyquist
rates shown on Figure 10 reflect the values
listed in the Typical AC Dynamics table.
INPUT BUFFERS
12/8
CS
READ CONTROL
A0
R/C
CE
EOC8
CK
Q
D
Q
A0 LATCH
EOC12
H DQ
CK
R
Figure 4. SPx74B Control Logic
DELAY
NIBBLE B ZERO
OVERRIDE
NIBBLE A, B
NIBBLE C
STS
A0
ADDRESS BUS
2 _12/8
4
A0
28
STS
27
DB11 (MSB)
26
25
24
23
SPx74B
22
21
20
19
18
17
16
DB0 (LSB)
DIG ¹⁵
COM
Figure 5. Interfacing SPx74B to 8–Bit Interface Bus
SP574B/674B/1674B/774B
12–Bit Sampling A/D Converters
10
DATA
BUS
© Copyright 2000 Sipex Corporation