FEATURES

· 5MHz (ADS-235/236) and 9MHz (ADS-237) sampling rates

· Low power

· Outstanding dynamic performance

· Fully differential or single-ended analog input

· 100MHz full power input bandwidth

· Integral sample-and-hold

· Single +5V supply operation

· Internally generated DC bias Voltage

· 3.0/5.0V CMOS compatible digital output

· TTL/CMOS compatible digital inputs/outputs

ADS-235, ADS-236, ADS-237

12-Bit, 5MHz and 9MHz

Sampling A/D Converters

GENERAL DESCRIPTION

The ADS-235, ADS-236 and ADS-237 are monolithic, 12-bit,

sampling analog-to-digital converters fabricated in a CMOS

process. The converters are designed for applications where

high speed, wide bandwidth and low power dissipation are

essential. These characteristics are provided through the use

of a fully differential sampling pipeline A/D architecture with

digital error correction logic.

The ADS-235, ADS-236 and ADS-237 offer excellent dynamic

performance while consuming only 300mW. The digital output

circuit is separate and can be powered from either a 3V or 5V

supply allowing the user to interface with 3V logic, if desired.

The ADS-235, ADS-236 and ADS-237 provide the user with

an internally generated DC bias voltage output. This DC bias

voltage is ideal for AC coupled analog input applications.

The units are available in a 28-lead plastic SOIC package

and operate over the 0°C to 70°C and –40 to +85°C

temperature ranges.

INPUT/OUTPUT CONNECTIONS

Figure 1. ADS-235, ADS-236 and ADS-237 Functional Block Diagram

PIN FUNCTION

PIN FUNCTION

DATEL, Inc., Mansfield, MA 02048 (USA)

· Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356 · Email: sales@datel.com · Internet: www.datel.com

®®

1

CLK, CLOCK

28

BIT 12

2

27

BIT 11

3

DGND1

26

BIT 10

4

25

BIT 9

5

DGND1

24

BIT 8

BIT 7

7

AGND

22

21

DGND2

20

BIT 6

10

19

BIT 5

11

18

BIT 4

12

17

BIT 3

13

AGND

16

BIT 2

14

BIT 1 (MSB)

Reference

4-Bit

Flash A/D

4-Bit

DAC

4-Bit

DAC

Stage 4

2.3 Volt

DC Bias Output

15 Bit 1 (MSB)

16 Bit 2

17 Bit 3

18 Bit 4

19 Bit 5

20 Bit 6

23 Bit 7

24 Bit 8

25 Bit 9

26 Bit 10

27 Bit 11

28 Bit 12 (LSB)

X8

+

–

+

–

Digital Delay

and

Error

Correction

Clock

1 CLK

2, 4

3, 5

DGND 1

6, 14

7, 13

AGND

22

21

DGND 2

9

Stage 3

4-Bit

Flash A/D

Stage 1

X8

S/H

4-Bit

Flash A/D

11

12

8

10