Philips Semiconductors

Product data

ADC0803/0804

CMOS 8-bit A/D converters

2002 Oct 17

13

20

D GND

A GND

A/D

CS

1

2

3

4

5

6

7

8

17 RD

INTO

WR

D0

D1

D2

D3

D4

D5

D6

D7

+5 V

40

16

12

39

P1.0

P1.1

P1.2

P1.3

P1.4

P1.5

P1.6

P1.7

P0.0

SCN8051

OR

SCN80C51

18

17

16

15

14

13

12

11

2

3

5

1

RD

INTR

WR

19 CLK R

10 k

Ω

4 CLK IN

6

7

ANALOG

INPUTS

12

11

56 pF

SL00028

Figure 13. SCN8051 Interfacing

18

17

16

15

14

13

12

11

D0

D1

D2

D3

D4

D5

D6

D7

A/D

OE

DATA

BUS

8–BIT

BUFFER

N74LS241

N74LS244

N74LS541

SL00029

Figure 14. Buffering the A/D Output to Drive High Capacitance

Loads and for Driving Off-Board Loads

A/D

4.7 k

Ω

1.5 k

Ω

1

µF

0.47

µF

22 k

Ω

470

Ω

Ct

18 k

Ω

+5 V

NE5521

LVDT

IN4148

3.3 k

Ω

2 k

Ω

2 k

Ω

+5 V

100

Ω

FULL SCALE

ADJUST

820

Ω

SL00030

4.7 k

Ω

2 k

Ω

Figure 15. Digitizing a Transducer Interface Output