|
Harris |
www.DataSheet4U.com
Semiconductor
August 1997
ADC0802, ADC0803
ADC0804
8-Bit, Microprocessor-
Compatible, A/D Converters
Features
Description
• 80C48 and 80C80/85 Bus Compatible - No Interfacing
Logic Required
• Conversion Time < 100µs
• 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
• 0V to 5V Analog Voltage Input Range (Single + 5V Supply)
• No Zero-Adjust Required
The ADC0802 family are CMOS 8-Bit, successive-approxi-
mation 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.
Ordering Information
PART NUMBER
ADC0802LCN
ADC0802LCD
ADC0802LD
ADC0803LCN
ADC0803LCD
ADC0803LCWM
ADC0803LD
ADC0804LCN
ADC0804LCD
ADC0804LCWM
ERROR
±1/2 LSB
±3/4 LSB
±1 LSB
±1/2 LSB
±3/4 LSB
±1 LSB
±1 LSB
±1 LSB
±1 LSB
±1 LSB
EXTERNAL CONDITIONS
VREF/2 = 2.500VDC (No Adjustments)
VREF/2 Adjusted for Correct Full Scale
Reading
VREF/2 = 2.500VDC (No Adjustments)
TEMP. RANGE (oC)
PACKAGE
0 to 70
20 Ld PDIP
-40 to 85
20 Ld CERDIP
-55 to 125
20 Ld CERDIP
0 to 70
20 Ld PDIP
-40 to 85
20 Ld CERDIP
-40 to 85
20 Ld SOIC
-55 to 125
20 Ld CERDIP
0 to 70
20 Ld PDIP
-40 to 85
20 Ld CERDIP
-40 to 85
20 Ld SOIC
PKG. NO
E20.3
F20.3
F20.3
E20.3
F20.3
M20.3
F20.3
E20.3
F20.3
M20.3
Pinout
Typical Application Schematic
ADC0802, ADC0803, ADC0804
(PDIP, CERDIP)
TOP VIEW
CS 1
RD 2
WR 3
CLK IN 4
INTR 5
VIN (+) 6
VIN (-) 7
AGND 8
VREF/2 9
DGND 10
20 V+ OR VREF
19 CLK R
18 DB0 (LSB)
17 DB1
16 DB2
15 DB3
14 DB4
13 DB5
12 DB6
11 DB7 (MSB)
ANY
µPROCESSOR
1 CS
2 RD
V+ 20
CLK R 19
+5V 150pF
3 WR CLK IN 4 10K
5 INTR
11 DB7
12 DB6
13 DB5
14 DB4
15 DB3
16 DB2
17 DB1
18 DB0
VIN (+)
VIN (-)
AGND
VREF/2
DGND
6
7
8
9
10
DIFF
INPUTS
VREF/2
8-BIT RESOLUTION
OVER ANY
DESIRED
ANALOG INPUT
VOLTAGE RANGE
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
Copyright © Harris Corporation 1997
6-5
File Number 3094.1
www.DataSheet4U.com
Functional Diagram
ADC0802, ADC0803, ADC0804
2
RD
1
CS 3
WR
SET
“1” = RESET SHIFT REGISTER
Q “0” = BUSY AND RESET STATE
READ
RESET
CLK R
19
CLK IN
4
CLK OSC
10
DGND
CLK A
CLK
GEN CLKS
G1 RESET
START F/F
V+ 20
(VREF)
9
VREF/2
LADDER
AND
DECODER
INPUT PROTECTION
FOR ALL LOGIC INPUTS
INPUT
TO INTERNAL
CIRCUITS
BV = 30V
CLK
D
DFF1
Q
CLK B
MSB
D
SUCCESSIVE
APPROX.
REGISTER
AND LATCH
8-BIT
SHIFT
REGISTER
R
RESET
START
CONVERSION
IF RESET = “0”
INTR F/F
AGND 8
6
VIN (+)
7
VIN (-)
DAC
VOUT
V+
+
∑
-
LSB
Q
COMP
-
+
CLK A
D
DFF2
Q
THREE-STATE
OUTPUT LATCHES
XFER
G2
MSB
LSB
11 12 13 14 15 16 17 18
DIGITAL OUTPUTS
THREE-STATE CONTROL
“1” = OUTPUT ENABLE
SET
CONV. COMPL.
8 X 1/f
Q
5
INTR
6-6
|