®
®
ADS-930
Gain Adjust Procedure
1. Apply +4.999771V to the ANALOG INPUT (pin 3) for bipolar
gain adjust or apply –9.999771V to pin 3 for unipolar gain
adjust.
2. For a unipolar input - adjust the gain potentiometer until all
output bits are 1's and the LSB flickers between a 1 and 0
with pin 8 tied high (straight binary) or until all output bits
are 0's and the LSB flickers between a 1 and 0 with pin 8
tied low (complementary binary).
For a bipolar input - adjust the gain potentiometer until all
output bits are 1's and the LSB flickers between a 1 and 0
with pin 8 tied low (complementary offset binary) or until all
output bits are 0's and the LSB flickers between a 1 and 0
with pin 8 tied high (offset binary).
3. Two's complement coding requires using pin 40. With pin 8
tied high, adjust the gain trimpot until the output code
flickers equally between 1000 0000 0000 0000 and 1000
0000 0000 0001.
specified over operating temperature (case) ranges of
0 to +70°C and –55 to +125°C. All room-temperature
(T
A
= +25°C) production testing is performed without the use of
heat sinks or forced-air cooling. Thermal impedance figures
for each device are listed in their respective specification
tables.
These devices do not normally require heat sinks, however,
standard precautionary design and layout procedures should
be used to ensure devices do not overheat. The ground and
power planes beneath the package, as well as all pcb signal
runs to and from the device, should be as heavy as possible to
help conduct heat away from the package. Electrically-
insulating, thermally-conductive "pads" may be installed
underneath the package. Devices should be soldered to
boards rather than "socketed", and of course, minimal air flow
over the surface can greatly help reduce the package
temperature.
In more severe ambient conditions, the package/junction
temperature of a given device can be reduced dramatically
(typically 35%) by using one of DATEL's HS Series heat sinks.
See Ordering Information for the assigned part number. See
page 1-183 of the DATEL Data Acquisition Components
Catalog for more information on the HS Series. Request
DATEL Application Note AN-8, "Heat Sinks for DIP Data
Converters," or contact DATEL directly, for additional data.
N+1
THERMAL REQUIREMENTS
All DATEL sampling A/D converters are fully characterized and
N
START
CONVERT
175ns min., 200ns typ., 215ns max .
10ns min., 25ns max.
Acquisition Time
INTERNAL S/H
Hold 1.54µs typ.
460ns typ. 545ns max.
140ns max.
EOC
780ns ±30ns
Conversion Time
700ns ±30ns
10ns min.
25ns max.
1.39µs min.
OUTPUT
DATA
Data N-1 Valid
Data N Valid
30ns min .
Note: Scale is approximately 50ns per division.
Invalid
Data
Figure 3. ADS-930 Timing Diagram
Figure 4. FFT Analysis of ADS-930
6
MURATA-PS [ MURATA POWER SOLUTIONS INC. ]
