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Figure 1. ADS-117 Functional Block Diagram

DATEL, Inc., 11 Cabot Boulevard, Mansfield, MA 02048-1151 (U.S.A.)

• Tel: (508) 339-3000 Fax: (508) 339-6356 • For immediate assistance: (800) 233-2765

ADS-117

12-Bit, 2MHz, Low-Power

Sampling A/D Converters

FEATURES

• 12-bit resolution

• No missing codes

• 2MHz minimum throughput

• Functionally complete

• Small 24-pin DDIP

• Low-power, 1.6 Watts

• Three-state output buffers

• Samples to Nyquist frequencies

GENERAL DESCRIPTION

DATEL's ADS-117 is a functionally complete, 12-bit, 2MHz,

sampling A/D converter. Its standard, 24-pin, double-width

DIP contains a fast-settling sample-hold amplifier, a 12-bit

subranging (two-step) A/D converter, a precision reference,

three-state output register and all the timing and control logic

necessary to operate from a single start convert pulse. Digital

input and output levels are TTL.

Total harmonic distortion (THD) and signal-to-noise ratio

(including distortion) typically run –78dB and 70dB,

respectively, with full scale inputs up to 100kHz. The ADS-

117 requires ±15V and +5V power supplies and typically

consumes 1.6 Watts. Models are available for use in either

commercial (0 to +70°C) or military (–55 to +125°C) operating

temperature ranges.

INPUT/OUTPUT CONNECTIONS

PIN

FUNCTION

PIN

FUNCTION

1

BIT 12 (LSB)

24

–15V SUPPLY

2

BIT 11

23

ANALOG GROUND

3

BIT 10

22

+15V SUPPLY

4

BIT 9

21

+10V REFERENCE

5

BIT 8

20

BIPOLAR

6

BIT 7

19

ANALOG INPUT

7

BIT 6

18

COMP BIN

8

BIT 5

17

ENABLE (1-12)

9

BIT 4

16

START CONVERT

10

BIT 3

15

EOC

11

BIT 2

14

DIGITAL GROUND

12

BIT 1 (MSB)

13

+5V SUPPLY

REF

12 BIT 1 (MSB)

11 BIT 2

10 BIT 3

9

BIT 4

8

BIT 5

7

BIT 6

6

BIT 7

5

BIT 8

4

BIT 9

3

BIT 10

2

BIT 11

1

BIT 12 (LSB)

TIMING AND

CONTROL LOGIC

BIPOLAR 20

+10V REF. 21

START CONVERT 16

EOC 15

DAC

FLASH

ADC

COMP BIN 18

BUFFER

–

+

S/H

ANALOG INPUT 19

17 ENABLE (1-12)

13

+5V SUPPLY

22

+15V SUPPLY

23

ANALOG GROUND

14

DIGITAL GROUND

24

–15V SUPPLY