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Semiconductor
ADC0802, ADC0803 ADC0804
8-Bit, MicroprocessorCompatible, A/D Converters
Description
The ADC0802 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 commonmode-rejection and permits offsetting the analog zero-inputvoltage 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.
August 1997
Features
• 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
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)
TEMP. RANGE (oC) 0 to 70 -40 to 85 -55 to 125
PACKAGE 20 Ld PDIP 20 Ld CERDIP 20 Ld CERDIP 20 Ld PDIP 20 Ld CERDIP 20 Ld SOIC 20 Ld CERDIP 20 Ld PDIP 20 Ld CERDIP 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
VREF/2 Adjusted for Correct Full Scale Reading
0 to 70 -40 to 85 -40 to 85 -55 to 125
VREF/2 = 2.500VDC (No Adjustments)
0 to 70 -40 to 85 -40 to 85
Pinout
ADC0802, ADC0803, ADC0804 (PDIP, CERDIP) TOP VIEW
CS RD WR CLK IN INTR VIN (+) VIN (-) AGND VREF/2 1 2 3 4 5 6 7 8 9 20 V+ OR VREF 19 CLK R
Typical Application Schematic
1 2 3 5 11 µP BUS ANY µPROCESSOR 12 13 14 15 16 17 18 CS RD WR INTR DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 VIN (+) VIN (-) 6 7 DIFF INPUTS VREF/2 8-BIT RESOLUTION OVER ANY DESIRED ANALOG INPUT VOLTAGE RANGE V+ 20 CLK R 19 CLK IN 4 +5V 10K 150pF
18 DB0 (LSB) 17 DB1 16 DB2 15 DB3 14 DB4 13 DB5 12 DB6 11 DB7 (MSB)
AGND 8 VREF/2 9 DGND 10
DGND 10
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures. Copyright
© Harris Corporation 1997
File Number
3094.1
6-5
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ADC0802, ADC0803, ADC0804
Functional Diagram
2 1 3 “1” = RESET SHIFT REGISTER “0” = BUSY AND RESET STATE
RD CS WR
READ
SET
Q
RESET
CLK R 19 CLK A CLK IN 4 CLK OSC 10 DGND CLK GEN CLKS
INPUT PROTECTION FOR ALL LOGIC INPUTS INPUT G1 TO INTERNAL CIRCUITS RESET BV = 30V START F/F D DFF1 Q CLK
CLK B MSB V+ (VREF) 20 LADDER AND DECODER 9 SUCCESSIVE APPROX. REGISTER AND LATCH D 8-BIT SHIFT REGISTER R RESET DAC VOUT V+ COMP LSB CLK A D DFF2 Q + Q
START CONVERSION
IF RESET = “0”
VREF/2
INTR F/F
AGND
8
VIN (+)
6
∑
+
-
THREE-STATE OUTPUT LATCHES MSB LSB CONV. COMPL. 11 12 13 14 15 16 17 18 8 X 1/f DIGITAL OUTPUTS THREE-STATE CONTROL “1” = OUTPUT ENABLE XFER G2 SET
Q
VIN (-)
7
5 INTR
6-6
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ADC0802, ADC0803, ADC0804
Thermal Information
Thermal Resistance (Typical, Note 1) θJA (oC/W) θJC (oC/W) PDIP Package . . . . . . . . . . . . . . . . . . . . . 125 N/A CERDIP Package . . . . . . . . . . . . . . . . . . 80 20 SOIC Package . . . . . . . . . . . . . . . . . . . . . 120 N/A Maximum Junction Temperature Hermetic Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175oC Plastic Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150oC Maximum Storage Temperature Range . . . . . . . . . .-65oC to 150oC Maximum Lead Temperature (Soldering, 10s) . . . . . . . . . . . . 300oC (SOIC - Lead Tips Only)
Absolute Maximum Ratings
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5V Voltage at Any Input . . . . . . . . . . . . . . . . . . . . . . -0.3V to (V+ +0.3V)
Operating Conditions
Temperature Range ADC0802/03LD. . . . . . . . . . . . . . . . . . . . . . . . . . . -55oC to 125oC ADC0802/03/04LCD . . . . . . . . . . . . . . . . . . . . . . . . -40oC to 85oC ADC0802/03/04LCN . . . . . . . . . . . . . . . . . . . . . . . . . .0oC to 70oC ADC0803/04LCWM . . . . . . . . . . . . . . . . . . . . . . . . -40oC to 85oC
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTE: 1. θJA is measured with the component mounted on an evaluation PC board in free air.
Electrical Specifications
PARAMETER
(Notes 1, 7) TEST CONDITIONS MIN TYP MAX UNITS
CONVERTER SPECIFICATIONS V+ = 5V, TA = 25oC and fCLK.