ADS-927 ETC [List of Unclassifed Manufacturers], ADS-927 Datasheet - Page 5

• Manufacturer Part Number: ADS-927
• Description: 14-Bit, 1MHz, Low-Power Sampling A/D Converters
• Manufacturer: ETC [List of Unclassifed Manufacturers]

THERMAL REQUIREMENTS
All DATEL sampling A/D converters are fully characterized and
specified over operating temperature (case) ranges of
0 to +70°C and –55 to +125°C. All room-temperature
(T
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.
A
®
= +25°C) production testing is performed without the use of
INTERNAL S/H
CONVERT
OUTPUT
START
DATA
EOC
10ns
typ.
®
Notes: 1. f
Data (N – 1) Valid
200ns
±25ns
2. The ADS-927 is a pulse-triggered device. Its internal operations
N
are triggered by both the rising and falling edges of the start
convert pulse. When sampling at 1MHz, the start pulse must be
between 175 and 225nsec wide. For lower sampling rates, wider
start pulses may be used, however, a minimum pulse width low of
50nsec must be maintained.
s
= 1MHz.
610ns typ.
Conversion Time
Hold
480ns ±20ns
10ns typ.
Figure 4. ADS-927 Timing Diagram
Invalid
Data
Acquisition Time
390ns ±55ns
5
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
information.
70ns ±10ns
35ns max.
150ns max.
N + 1
Data N Valid (850ns min.)
ADS-927