FN3094 Rev 4.00

Page 1 of 17

August 2002

FN3094

Rev 4.00

August 2002

ADC0803, ADC0804

8-Bit, Microprocessor-Compatible, A/D Converters

DATASHEET

The ADC080X family are CMOS 8-Bit,

successive-approximation A/D converters which use a

modified potentiometric ladder and are designed to operate

with the 8080A control bus via three-state outputs. These

converters appear to the processor as memory locations or

I/O ports, and hence no interfacing logic is required.

The differential analog voltage input has good common-

mode-rejection and permits offsetting the analog zero-input-

voltage value. In addition, the voltage reference input can be

adjusted to allow encoding any smaller analog voltage span

to the full 8 bits of resolution.

Typical Application Schematic

Features

• 80C48 and 80C80/85 Bus Compatible - No Interfacing

Logic Required

• Conversion Time . . . . . . . . . . . . . . . . . . . . . . . . . . <100

s

• Easy Interface to Most Microprocessors

• Will Operate in a “Stand Alone” Mode

• Differential Analog Voltage Inputs

• Works with Bandgap Voltage References

• TTL Compatible Inputs and Outputs

• On-Chip Clock Generator

• Analog Voltage Input Range

(Single + 5V Supply) . . . . . . . . . . . . . . . . . . . . . . 0V to 5V

• No Zero-Adjust Required

• 80C48 and 80C80/85 Bus Compatible - No Interfacing

Logic Required

Pinout

ADC0803, ADC0804

(PDIP)

TOP VIEW

3

2

1

12

11

5

15

14

13

18

17

16

7

6

10

9

8

4

19

20

WR

RD

CS

INTR

CLK IN

CLK R

V+

DGND

AGND

ANY

PROCESSOR

8-BIT RESOLUTION

OVER ANY

DESIRED

ANALOG INPUT

VOLTAGE RANGE

DIFF

INPUTS

10K

150pF

+5V

11

12

13

14

15

16

17

18

20

19

10

9

8

7

6

5

4

3

2

1

WR

RD

CS

CLK IN

INTR

DGND

AGND

CLK R

Ordering Information

PART NUMBER

ERROR

EXTERNAL CONDITIONS

PACKAGE

PKG. NO

ADC0803LCN

1

Reading

0 to 70

20 Ld PDIP

E20.3

ADC0804LCN



1 LSB

0 to 70

20 Ld PDIP

E20.3