8

®

ADC71

OUTPUT DRIVE

Normally all ADC71 logic outputs will drive two standard

TTL loads; however, if long digital lines must be driver,

external logic buffers are recommended.

HEAT DISSIPATION

The ADC71 dissipates approximately 0.6W (typical) and the

packages have a case-to-ambient thermal resistance (

θ

25

°C/W. For operation above 85°C,

θ

by a heat sink or by forced air over the surface of the

package. See Figure 10 for

θ

the converter is mounted on a PC card, improved thermal

contact with the copper ground plane under the case can be

achieved using a silicone heat sink compound. On a 0.062"

thick PC card with a 16 square in (min) area, this techniques

will allow operation to 85

°C.

Ambient Temperature (°C)

25

10

0

60

70

80

90

100

110

125

FIGURE 10.

θ

RESOLUTION (Bits)

16

14

13

12

Connect Pin 32 to

Open

Pin 15

Pin 14

Pin 13

Maximum Conversion

Speed (

57

50

46.5

43

Maximum Nonlinearity

at 25

°C (% of FSR)

0.006

0.006

NOTES: (1) Max conversion time to maintain specified nonlinearity error.

(2) BH and KH models only.

TABLE III. Short-Cycle Connections and Specifications for

12- to 14-Bit Resolutions.