NSC ADC0804MWC, ADC0804LCWMX, ADC0804LCWM, ADC0804LCN, ADC0804LCJ Datasheet

ADC0801/ADC0802/ADC0803/ADC0804/ADC0805 8-Bit µP Compatible A/D Converters

General Description

The ADC0801, ADC0802, ADC0803, ADC0804 and ADC0805 are CMOS 8-bit successive approximation A/D converters that use a differential potentiometric ladder—similar to the 256R products. These converters are designed to allow operation with the NSC800 and INS8080A derivative control bus with TRI-STATE

output latches directly driving the data bus. These A/Ds appear like memory locations or I/O ports to the microprocessor and no interfacing logic is needed.

Differential analog voltage inputs allow increasing the common-mode rejection and 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.

Features

n Compatible with 8080 µP derivatives— no interfacing

logic needed - access time - 135 ns

n Easy interface to all microprocessors, or operates “stand

alone”

n Differential analog voltage inputs n Logic inputs and outputs meet both MOS and TTL

voltage level specifications

n Works with 2.5V (LM336) voltage reference n On-chip clock generator n 0V to 5V analog input voltage range with single 5V

supply

n No zero adjust required n 0.3" standard width 20-pin DIP package n 20-pin molded chip carrier or small outline package n Operates ratiometrically or with 5 V

, 2.5 VDC,or

analog span adjusted voltage reference

Key Specifications

n Resolution 8 bits n Total error

⁄4LSB,

⁄2LSB and±1 LSB

n Conversion time 100 µs

Connection Diagram

Ordering Information

TEMP RANGE 0˚C TO 70˚C 0˚C TO 70˚C −40˚C TO +85˚C

⁄4Bit Adjusted ADC0801LCN

ERROR

⁄2Bit Unadjusted ADC0802LCWM ADC0802LCN

⁄2Bit Adjusted ADC0803LCN

1Bit Unadjusted ADC0804LCWM ADC0804LCN ADC0805LCN/ADC0804LCJ

PACKAGE OUTLINE M20B—Small

Outline

N20A—Molded DIP

TRI-STATE®is a registered trademark of National Semiconductor Corp. Z-80

is a registered trademark of Zilog Corp.

ADC080X

Dual-In-Line and Small Outline (SO) Packages

DS005671-30

See Ordering Information

November 1999

ADC0801/ADC0802/ADC0803/ADC0804/ADC0805 8-Bit µP Compatible A/D Converters

Typical Applications

Error Specification (Includes Full-Scale,

Zero Error, and Non-Linearity)

Part Full- V

REF

/2=2.500 V

DCVREF

/2=No Connection

Number Scale (No Adjustments) (No Adjustments)

Adjusted

ADC0801

⁄4LSB

ADC0802

⁄2LSB

ADC0803

⁄2LSB

ADC0804

1 LSB

ADC0805

1 LSB

DS005671-1

8080 Interface

DS005671-31

ADC0801/ADC0802/ADC0803/ADC0804/ADC0805

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Absolute Maximum Ratings (Notes 1, 2)

If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.

Supply Voltage (V

) (Note 3) 6.5V

Voltage

Logic Control Inputs −0.3V to +18V At Other Input and Outputs −0.3V to (V

+0.3V)

Lead Temp. (Soldering, 10 seconds)

Dual-In-Line Package (plastic) 260˚C Dual-In-Line Package (ceramic) 300˚C Surface Mount Package

Vapor Phase (60 seconds) 215˚C

Infrared (15 seconds) 220˚C Storage Temperature Range −65˚C to +150˚C Package Dissipation at T

25˚C 875 mW

ESD Susceptibility (Note 10) 800V

Operating Ratings (Notes 1, 2)

Temperature Range T

MIN≤TA≤TMAX

ADC0804LCJ −40˚C≤TA≤+85˚C ADC0801/02/03/05LCN −40˚C≤T

≤+85˚C

ADC0804LCN 0˚C≤T

≤+70˚C

ADC0802/04LCWM 0˚C≤T

≤+70˚C

Range of V

4.5 VDCto 6.3 V

Electrical Characteristics

The following specifications apply for V

DC,TMIN≤TA≤TMAX

and f

CLK

640 kHz unless otherwise specified.

Parameter Conditions Min Typ Max Units

ADC0801: Total Adjusted Error (Note 8) With Full-Scale Adj.

⁄

LSB

(See Section 2.5.2)

ADC0802: Total Unadjusted Error (Note 8) V

REF

/2=2.500 V

⁄

LSB

ADC0803: Total Adjusted Error (Note 8) With Full-Scale Adj.

⁄

LSB

(See Section 2.5.2)

ADC0804: Total Unadjusted Error (Note 8) V

REF

/2=2.500 V

1 LSB

ADC0805: Total Unadjusted Error (Note 8) V

REF

/2-No Connection

1 LSB

REF

/2 Input Resistance (Pin 9) ADC0801/02/03/05 2.5 8.0 kΩ

ADC0804 (Note 9) 0.75 1.1 kΩ

Analog Input Voltage Range (Note 4) V(+) or V(−) Gnd–0.05 V

+0.05 V

DC Common-Mode Error Over Analog Input Voltage

1/16

⁄

LSB

Range

Power Supply Sensitivity V

10%Over

1/16

⁄

LSB

Allowed V

(+) and VIN(−)

Voltage Range (Note 4)

AC Electrical Characteristics

The following specifications apply for V

and T

MIN≤TA≤TMAX

unless otherwise specified.

Symbol Parameter Conditions Min Typ Max Units

Conversion Time f

CLK

640 kHz (Note 6) 103 114 µs

Conversion Time (Notes 5, 6) 66 73 1/f

CLK

Clock Frequency V

5V, (Note 5) 100 640 1460 kHz

Clock Duty Cycle 40 60

CR Conversion Rate in Free-Running INTR tied to WR with

8770 9708 conv/s

Mode CS=0V

DC,fCLK

640 kHz

W(WR)L

Width of WR Input (Start Pulse Width) CS=0VDC(Note 7) 100 ns

ACC

Access Time (Delay from Falling C

100 pF 135 200 ns

Edge of RD to Output Data Valid)

t1H,t

TRI-STATE Control (Delay C

10 pF, R

10k 125 200 ns

from Rising Edge of RD to

(See TRI-STATE Test

Hi-Z State) Circuits)

WI,tRI

Delay from Falling Edge 300 450 ns of WR or RD to Reset of INTR

Input Capacitance of Logic 5 7.5 pF Control Inputs

ADC0801/ADC0802/ADC0803/ADC0804/ADC0805

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AC Electrical Characteristics (Continued)

The following specifications apply for V

and T

MIN≤TA≤TMAX

unless otherwise specified.

Symbol Parameter Conditions Min Typ Max Units

OUT

TRI-STATE Output 5 7.5 pF

Capacitance (Data Buffers) CONTROL INPUTS [Note: CLK IN (Pin 4) is the input of a Schmitt trigger circuit and is therefore specified separately] V

(1) Logical “1” Input Voltage V

5.25 V

2.0 15 V

(Except Pin 4 CLK IN) V

(0) Logical “0” Input Voltage V

4.75 V

0.8 V

(Except Pin 4 CLK IN) I

(1) Logical “1” Input Current V

0.005 1 µA

(All Inputs) I

(0) Logical “0” Input Current V

−1 −0.005 µA

(All Inputs)

CLOCK IN AND CLOCK R

+ CLK IN (Pin 4) Positive Going 2.7 3.1 3.5 V

Threshold Voltage V

− CLK IN (Pin 4) Negative 1.5 1.8 2.1 V

Going Threshold Voltage V

CLK IN (Pin 4) Hysteresis 0.6 1.3 2.0 V

(VT+)−(VT−) V

OUT

(0) Logical “0” CLK R Output I

360 µA 0.4 V

Voltage V

4.75 V

OUT

(1) Logical “1” CLK R Output I

−360 µA 2.4 V

Voltage V

4.75 V

DATA OUTPUTS AND INTR

OUT

(0) Logical “0” Output Voltage

Data Outputs I

OUT

1.6 mA, V

4.75 V

0.4 V

INTR Output I

OUT

1.0 mA, V

4.75 V

0.4 V

OUT

(1) Logical “1” Output Voltage I

−360 µA, V

4.75 V

2.4 V

OUT

(1) Logical “1” Output Voltage I

−10 µA, V

4.75 V

4.5 V

OUT

TRI-STATE Disabled Output V

OUT

−3 µA

Leakage (All Data Buffers) V

OUT

3µA

SOURCE

OUT

Short to Gnd, T

25˚C 4.5 6 mA

SINK

OUT

Short to VCC,T

25˚C 9.0 16 mA

POWER SUPPLY

Supply Current (Includes f

CLK

640 kHz,

Ladder Current) V

REF

/2=NC, T

25˚C

and CS=5V ADC0801/02/03/04LCJ/05 1.1 1.8 mA ADC0804LCN/LCWM 1.9 2.5 mA

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.DC and AC electrical specifications do not apply when operating the device beyond its specified operating conditions.

Note 2: All voltages are measured with respect to Gnd, unless otherwise specified. The separate A Gnd point should always be wired to the D Gnd. Note 3: A zener diode exists, internally, from V

to Gnd and has a typical breakdown voltage of 7 VDC.

Note 4: For V

(−)≥ VIN(+) the digital output code will be 0000 0000.Twoon-chipdiodes are tied to eachanalog input (see block diagram) which will forward conduct

for analog input voltages one diode drop below ground or one diode drop greater than the V

supply. Be careful, during testing at low VCClevels (4.5V), as high level analog inputs (5V) can cause thisinputdiode to conduct–especiallyatelevatedtemperatures, and cause errors for analog inputsnearfull-scale. The spec allows 50 mV forward bias of eitherdiode.This means that as long astheanalog V

does not exceed the supply voltageby more than 50 mV, the output code will becorrect.

Toachievean absolute 0 V

to5VDCinput voltage range will therefore require a minimum supply voltage of 4.950 VDCover temperature variations, initial tolerance

and loading. Note 5: Accuracy is guaranteed at f

CLK

640 kHz. At higher clock frequencies accuracy can degrade. For lower clock frequencies, the duty cycle limits can be ex-

tended so long as the minimum clock high time interval or minimum clock low time interval is no less than 275 ns. Note 6: With an asynchronous start pulse, up to 8 clock periods may be required before the internal clock phases are proper to start the conversion process. The

start request is internally latched, see

Figure 4

and section 2.0.

ADC0801/ADC0802/ADC0803/ADC0804/ADC0805

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AC Electrical Characteristics (Continued)

Note 7: The CS input is assumed to bracket the WR strobe input and therefore timing is dependent on the WR pulse width. An arbitrarily wide pulse width will hold

the converter in a reset mode and the start of conversion is initiated by the low to high transition of the WR pulse (see timing diagrams). Note 8: None of these A/Ds requires a zero adjust (see section 2.5.1). To obtain zero code at other analog input voltages see section 2.5 and

Figure 7

Note 9: The V

REF

/2 pin is the center point of a two-resistor divider connected from VCCto ground. In all versions of the ADC0801, ADC0802, ADC0803, and

ADC0805, and in the ADC0804LCJ, each resistor is typically 16 kΩ. In all versions of the ADC0804 except the ADC0804LCJ, each resistor is typically 2.2 kΩ.

Note 10: Human body model, 100 pF discharged through a 1.5 kΩ resistor.

Typical Performance Characteristics

Logic Input Threshold Voltage vs. Supply Voltage

DS005671-38

Delay From Falling Edge of RD to Output Data Valid vs. Load Capacitance

DS005671-39

CLK IN Schmitt Trip Levels vs. Supply Voltage

DS005671-40

CLK

vs. Clock Capacitor

DS005671-41

Full-Scale Error vs Conversion Time

DS005671-42

Effect of Unadjusted Offset Error vs. V

REF

/2 Voltage

DS005671-43

Output Current vs Temperature

DS005671-44

Power Supply Current vs Temperature (Note 9)

DS005671-45

Linearity Error at Low V

REF

/2 Voltages

DS005671-46

ADC0801/ADC0802/ADC0803/ADC0804/ADC0805

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TRI-STATE Test Circuits and Waveforms

Timing Diagrams

(All timing is measured from the 50%voltage points)

DS005671-47

t1H,C

10 pF

DS005671-48

20 ns

DS005671-49

t0H,C

10 pF

DS005671-50

20 ns

DS005671-51

ADC0801/ADC0802/ADC0803/ADC0804/ADC0805

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Timing Diagrams (All timing is measured from the 50

voltage points) (Continued)

Typical Applications

Output Enable and Reset with INTR

DS005671-52

Note: Read strobe must occur 8 clock periods (8/f

CLK

) after assertion of interrupt to guarantee reset of INTR .

6800 Interface

DS005671-53

Ratiometeric with Full-Scale Adjust

DS005671-54

Note: before using caps at VINor V

REF

/2,

see section 2.3.2 Input Bypass Capacitors.

ADC0801/ADC0802/ADC0803/ADC0804/ADC0805

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Typical Applications (Continued)

Absolute with a 2.500V Reference

DS005671-55

*For low power, see also LM385–2.5

Absolute with a 5V Reference

DS005671-56

Zero-Shift and Span Adjust: 2V ≤ VIN≤ 5V

DS005671-57

Span Adjust: 0V ≤ VIN≤ 3V

DS005671-58

ADC0801/ADC0802/ADC0803/ADC0804/ADC0805

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Typical Applications (Continued)

Directly Converting a Low-Level Signal

DS005671-59

REF

/2=256 mV

A µP Interfaced Comparator

DS005671-60

For: V

(+)>VIN(−)

Output=FF

HEX

For: V

(+)<VIN(−)

Output=00

HEX

1 mV Resolution with µP Controlled Range

DS005671-61

REF

/2=128 mV 1 LSB=1mV V

DAC≤VIN

≤(V

DAC

+256 mV)

0 ≤ V

DAC

2.5V

ADC0801/ADC0802/ADC0803/ADC0804/ADC0805

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Typical Applications (Continued)

Digitizing a Current Flow

DS005671-62

Self-Clocking Multiple A/Ds

DS005671-63

* Use a large R value to reduce loading at CLK R output.

External Clocking

DS005671-64

100 kHz≤f

CLK

≤1460 kHz

ADC0801/ADC0802/ADC0803/ADC0804/ADC0805

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Typical Applications (Continued)

Self-Clocking in Free-Running Mode

DS005671-65

*After power-up, a momentary grounding of the WR input is needed to guarantee operation.

µP Interface for Free-Running A/D

DS005671-66

Operating with “Automotive” Ratiometric Transducers

DS005671-67

*VIN(−)=0.15 V

15%of VCC≤V

XDR

≤85%of V

Ratiometric with V

REF

/2 Forced

DS005671-68

µP Compatible Differential-Input Comparator with Pre-Set VOS(with or without Hysteresis)

DS005671-69

*See

Figure 5

to select R value

DB7=“1” for V

(+)>VIN(−)+(V

REF

/2) Omit circuitry within the dotted area if hysteresis is not needed

ADC0801/ADC0802/ADC0803/ADC0804/ADC0805

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Typical Applications (Continued)

Handling

10V Analog Inputs

DS005671-70

*Beckman Instruments#694-3-R10K resistor array

Low-Cost, µP Interfaced, Temperature-to-Digital

Converter

DS005671-71

µP Interfaced Temperature-to-Digital Converter

DS005671-72

*Circuit values shown are for 0˚C≤TA≤+128˚C **

Can calibrate each sensor to allow easy replacement, then A/D can be calibrated with a pre-set input voltage.

ADC0801/ADC0802/ADC0803/ADC0804/ADC0805

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Typical Applications (Continued)

Handling

5V Analog Inputs

DS005671-33

*Beckman Instruments#694-3-R10K resistor array

Read-Only Interface

DS005671-34

µP Interfaced Comparator with Hysteresis

DS005671-35

Protecting the Input

DS005671-9

Diodes are 1N914

ADC0801/ADC0802/ADC0803/ADC0804/ADC0805

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