IN N O VA T IO N a n d E X C ELL E N C E

®

®

GENERAL DESCRIPTION

DATEL's ADS-325A is a low power, 10-bit, 20MHz, CMOS

sampling A/D converter. Its small 48 pin plastic LQFP package

contains a S/H amplifier, a 3-state output register, linearity

calibration circuitry, and all necessary control logic. Only two

external reference voltages, an A/D clock and a few digital

inputs are required. The A/D clock may be applied with 50%

duty cycle.

The excellent dynamic performance includes a spurious free

dynamic range of 65dB and a signal-to-noise ratio with

distortion of 54dB with a 3MHz input. ADS-325A is capable of

operating from a single +5V power supply and typically

consumes only 150mW. It can also operate from a +5V analog

circuitry. The ADS-325A is ideally suited for high quality video/

CCD imaging applications.

FEATURES

• 10-bit, 20MHz sampling

• ±1LSB max. differential nonlinearity

• Internal calibration circuit

• Internal S/H amplifier

• 70MHz input bandwidth

• TTL/CMOS compatible in-out logic

• Latched three-state output data

• Single +5V supply

• Low 150mW power dissipation

• Small 48 pin LQFP package

• Low cost

Figure 1. ADS-325A Functional Block Diagram

INPUT/OUTPUT CONNECTIONS

PIN

FUNCTION

1

BIT 10 (LSB)

2

BIT 9

3

BIT 8

4

BIT 7

5

BIT 6

6

DIGITAL GROUND (DGND)

7

8

BIT 5

9

BIT 4

10

BIT 3

11

BIT 2

12

BIT 1 (MSB)

13

TEST PIN

14

TEST SIGNAL IN

15

RESET

16

DIGITAL GROUND (DGND)

17

SELECT (SEL)

18

+AVS (Analog)

19

TEST MODE

20

LINV

21

MINV

22

A/D CLOCK

23

OUTPUT ENABLE (OE)

24

CHIP ENABLE (CE)

PIN

FUNCTION

48

DIGITAL GROUND (DGND)

47

NO CONNECTION

46

NO CONNECTION

45

44

ANALOG GROUND (AGND)

43

ANALOG GROUND (AGND)

42

TEST SIGNAL IN

41

CALIBRATION (CAL)

40

NO CONNECTION

39

38

TEST SIGNAL OUT

37

TEST SIGNAL IN

36

ANALOG GROUND (AGND)

35

34

33

NO CONNECTION

32

NO CONNECTION

31

NO CONNECTION

30

29

28

ANALOG GROUND (AGND)

27

ANALOG GROUND (AGND)

26

+AVS (Analog)

25

+AVS (Analog)

ADS-325A

10-Bit, 20MHz

Sampling A/D Converter

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 BIT 10 (LSB)

2 BIT 9

3 BIT 8

4 BIT 7

5 BIT 6

8 BIT 5

9 BIT 4

10 BIT 3

11 BIT 2

12 BIT 1 (MSB)

35

34

29

30

39

23

24

22

21 MINV

20 LINV

19 TEST MODE

17 SEL

15 RESET

A/D CLOCK

CE

OE

S/H AMP

COARSE

COMPARISON

AND

ENCODE

DAC

CALIBRATION

UNIT

TIMING GEN.

FINE

LATCH

COARSE

CORRECTION

AND

LATCH

FINE

COMPARISON

AND

ENCODE

41 CAL

x8

+

AGND

44

25

43

27

28

36

18

26

SENSE

AMP

#1

AUTOCALIBRATION

PULSE

GENERATOR

SENSE

AMP

#2