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ADS-942

5

THERMAL REQUIREMENTS

All DATEL sampling A/D converters are fully characterized and

specified over operating temperature (case) ranges of 0 to

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

information.

Figure 4. FFT Analysis of ADS-942

0

–10

–20

–30

–40

–50

–60

–70

–80

–90

–100

–110

–120

–130

–140

–150

Frequency (MHz)

(fs = 2MHz, fin = 490kHz, Vin = –0.5dB, 16,384-point FFT)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1