NSC ADC0820BMWC, ADC0820BMDC, ADC0820BCJ, ADC0820CMWC, ADC0820CMDC Datasheet

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ADC0820 8-Bit High Speed µP Compatible A/D Converter with Track/Hold Function

General Description

By using a half-flash conversion technique, the 8-bit ADC0820 CMOS A/D offers a 1.5 µs conversion time and dissipates only 75 mW of power. The half-flash technique consists of 32 comparators, a most significant 4-bitADCand a least significant 4-bit ADC.

The input to the ADC0820 is tracked and held by the input sampling circuitry eliminating the need for an external sample-and-hold for signals moving at less than 100 mV/µs.

For ease of interface to microprocessors, the ADC0820 has been designed to appear as a memory location or I/O port without the need for external interfacing logic.

Key Specifications

Resolution 8 Bits

Conversion Time 2.5 µs Max (RD Mode)

1.5 µs Max (WR-RD Mode)

Low Power 75 mW Max

Total Unadjusted

Error

⁄2LSB and±1 LSB

Features

n Built-in track-and-hold function n No missing codes n No external clocking n Single supply —5 V

n Easy interface to all microprocessors, or operates

stand-alone

n Latched STRI-STATE output n Logic inputs and outputs meet both MOS and T

voltage level specifications

n Operates ratiometrically or with any reference value

equal to or less than V

n 0V to 5V analog input voltage range with single 5V

supply

n No zero or full-scale adjust required n Overflow output available for cascading n 0.3" standard width 20-pin DIP n 20-pin molded chip carrier package n 20-pin small outline package n 20-pin shrink small outline package (SSOP)

Connection and Functional Diagrams

Dual-In-Line, Small Outline

and SSOP Packages

DS005501-1

Top View

Molded Chip Carrier

Package

DS005501-33

June 1999

ADC0820 8-Bit High Speed µP Compatible A/D Converter with Track/Hold Function

Connection and Functional Diagrams (Continued)

Ordering Information

Part Number Total Package Temperature

Unadjusted Error Range

ADC0820BCV V20A—Molded Chip Carrier 0˚C to +70˚C ADC0820BCWM

⁄2LSB M20B—Wide Body Small Outline 0˚C to +70˚C ADC0820BCN N20A—Molded DIP 0˚C to +70˚C ADC0820CCJ

1 LSB

J20A—Cerdip −40˚C to +85˚C ADC0820CCWM M20B—Wide Body Small Outline 0˚C to +70˚C ADC0820CIWM M20B—Wide Body Small Outline −40˚C to +85˚C ADC0820CCN N20A—Molded DIP 0˚C to +70˚C

DS005501-2

FIGURE 1.

ADC0820

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Absolute Maximum Ratings (Notes 1, 2)

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

Supply Voltage (V

) 10V

Logic Control Inputs −0.2V to V

+0.2V

Voltage at Other Inputs and Output −0.2V to V

+0.2V Storage Temperature Range −65˚C to +150˚C Package Dissipation at T

= 25˚C 875 mW Input Current at Any Pin (Note 5) 1 mA Package Input Current (Note 5) 4 mA ESD Susceptability (Note 9) 1200V Lead Temp. (Soldering, 10 sec.)

Dual-In-Line Package (plastic) 260˚C

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

Vapor Phase (60 sec.) 215˚C Infrared (15 sec.) 220˚C

Operating Ratings (Notes 1, 2)

Temperature Range T

MIN≤TA≤TMAX

ADC0820CCJ −40˚C≤TA≤+85˚C ADC0820CIWM −40˚C≤T

≤+85˚C

ADC0820BCN, ADC0820CCN 0˚C≤T

≤70˚C

ADC0820BCV 0˚C≤T

≤70˚C

ADC0820BCWM, ADC0820CCWM 0˚C≤T

≤70˚C

Range 4.5V to 8V

Converter Characteristics

The following specifications apply for RD mode (pin 7=0), VCC=5V, V

REF

(+)=5V,and V

REF

(−)=GND unless otherwise specified.

Boldface limits apply from T

MIN

to T

MAX

; all other limits TA=Tj=25˚C.

Parameter Conditions ADC0820BCN, ADC0820CCN Limit

Units

ADC0820CCJ ADC0820BCV, ADC0820BCWM

ADC0820CCWM, ADC0820CIWM

Typ Tested Design Typ Tested Design

(Note 6) Limit Limit (Note 6) Limit Limit

(Note 7) (Note 8) (Note 7) (Note 8) Resolution 8 8 8 Bits Total Unadjusted ADC0820BCN, BCWM

⁄

LSB

Error ADC0820CCJ

1 LSB

(Note 3) ADC0820CCN, CCWM, CIWM,

1 LSB

ADC0820CCMSA

1 LSB

Minimum Reference 2.3 1.00 2.3 1.2 kΩ Resistance Maximum Reference 2.3 6 2.3 5.3 6 kΩ Resistance Maximum V

REF

(+) V

V Input Voltage Minimum V

REF

(−) GND GND GND V Input Voltage Minimum V

REF

(+) V

REF

(−) V

REF

(−) V

REF

(−) V

Input Voltage Maximum V

REF

(−) V

REF

(+) V

REF

(+) V

REF

(+) V

Input Voltage Maximum V

Input VCC+0.1 VCC+0.1 VCC+0.1 V Voltage Minimum V

Input GND−0.1 GND−0.1 GND−0.1 V Voltage Maximum Analog CS =V

Input Leakage VIN=V

3 0.3 3 µA

Current V

=GND −3 −0.3 −3 µA

Power Supply V

=5V±5%

1/16

⁄

1/16

⁄

LSB

Sensitivity

ADC0820

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DC Electrical Characteristics

The following specifications apply for VCC=5V, unless otherwise specified. Boldface limits apply from T

MIN

to T

MAX

; all other

limits T

A=TJ

=25˚C.

Parameter Conditions ADC0820BCN, ADC0820CCN Limit

Units

ADC0820CCJ ADC0820BCV, ADC0820BCWM

ADC0820CCWM, ADC0820CIWM

Typ Tested Design Typ Tested Design

(Note 6) Limit Limit (Note 6) Limit Limit

(Note 7) (Note 8) (Note 7) (Note 8)

IN(1)

, Logical “1” VCC=5.25V CS , WR , RD 2.0 2.0 2.0 V Input Voltage Mode 3.5 3.5 3.5 V V

IN(0)

, Logical “0” VCC=4.75V CS , WR , RD 0.8 0.8 0.8 V Input Voltage Mode 1.5 1.5 1.5 V I

IN(1)

, Logical “1” V

IN(1)

=5V; CS , RD 0.005 1 0.005 1 µA

Input Current V

IN(1)

=5V; WR 0.1 3 0.1 0.3 3 µA

IN(1)

=5V; Mode 50 200 50 170 200 µA

IN(0)

, Logical “0” V

IN(0)

=0V;CS,RD,WR, −0.005 −1 −0.005 −1 µA Input Current Mode V

OUT(1)

, Logical “1” VCC=4.75V, I

OUT

=−360 µA; 2.4 2.8 2.4 V

Output Voltage DB0–DB7, OFL , INT

VCC=4.75V, I

OUT

=−10 µA; 4.5 4.6 4.5 V

DB0–DB7, OFL , INT

OUT(0)

, Logical “0” VCC=4.75V, I

OUT

=1.6 mA; 0.4 0.34 0.4 V Output Voltage DB0–DB7, OFL , INT , RDY I

OUT

, TRI-STATE V

OUT

=5V; DB0–DB7, RDY 0.1 3 0.1 0.3 3 µA

Output Current V

OUT

=0V; DB0–DB7, RDY −0.1 −3 −0.1 −0.3 −3 µA

SOURCE

, Output V

OUT

=0V; DB0–DB7, OFL −12 −6 −12 −7.2 −6 mA

Source Current INT

−9 −4.0 −9 −5.3 −4.0 mA

SINK

, Output Sink V

OUT

=5V; DB0–DB7, OFL , 14 7 14 8.4 7 mA Current INT , RDY ICC, Supply Current CS =WR =RD =0 7.5 15 7.5 13 15 mA

AC Electrical Characteristics

The following specifications apply for VCC=5V, tr=tf=20 ns, V

REF

(+)=5V, V

REF

(−)=0V and TA=25˚C unless otherwise specified.

Typ Tested Design

Parameter Conditions (Note 6) Limit Limit Units

(Note 7) (Note 8)

CRD

, Conversion Time for RD

Mode

Pin 7 = 0,

Figure 2

1.6 2.5 µs

ACC0

, Access Time (Delay from Pin 7 = 0,

Figure 2

CRD

+20 t

CRD

+50 ns

Falling Edge of RD to Output Valid)

CWR-RD

, Conversion Time for Pin 7 = VCC;tWR= 600 ns, 1.52 µs

WR-RD Mode t

=600 ns;

Figures 3, 4

tWR, Write Time Min Pin 7 = VCC;

Figures 3, 4

600 ns

Max (Note 4) See Graph 50 µs

, Read Time Min Pin 7 = VCC;

Figures 3, 4

600 ns

(Note 4) See Graph

ACC1

, Access Time (Delay from Pin 7 = VCC,t

tI;

Figure 3

Falling Edge of RD to Output Valid)

=15 pF 190 280 ns

=100 pF 210 320 ns

ADC0820

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AC Electrical Characteristics (Continued)

The following specifications apply for VCC=5V, tr=tf=20 ns, V

REF

(+)=5V, V

REF

(−)=0V and TA=25˚C unless otherwise specified.

Typ Tested Design

Parameter Conditions (Note 6) Limit Limit Units

(Note 7) (Note 8)

ACC2

, Access Time (Delay from Falling Edge of RD to Output Valid)

Pin 7 = V

CC,tRD

tI;

Figure 4

CL=15 pF 70 120 ns C

=100 pF 90 150 ns

ACC3

, Access Time (Delay from Rising Edge of RDY to Output Valid)

PULLUP

= 1k and CL=15pF 30 ns

, Internal Comparison Time Pin 7=VCC;

Figures 4, 5

800 1300 ns

=50 pF

1H,t0H

, TRI-STATE Control RL=1k, CL=10 pF 100 200 ns (Delay from Rising Edge of RD to Hi-Z State) t

INTL

, Delay from Rising Edge of Pin 7 = VCC,CL=50pF

WR to Falling Edge of INT

tI;

Figure 4

tI;

Figure 3

tRD+200 tRD+290 ns

INTH

, Delay from Rising Edge of

Figures 2, 3, 4

125 225 ns

RD to Rising Edge of INT

CL=50 pFc

INTHWR

, Delay from Rising Edge of

Figure 5

,CL=50 pF 175 270 ns WR to Rising Edge of INT t

RDY

, Delay from CS to RDY

Figure 2

,CL=50 pF, Pin 7 =0 50 100 ns t

, Delay from INT to Output Valid

Figure 5

20 50 ns

, Delay from RD to INT Pin 7=VCC,t

200 290 ns

Figure 3

tP, Delay from End of Conversion

Figures 2, 3, 4, 5

500 ns to Next Conversion (Note 4) See Graph Slew Rate, Tracking 0.1 V/µs C

VIN

, Analog Input Capacitance 45 pF

OUT

, Logic Output Capacitance 5 pF

, Logic Input Capacitance 5 pF

Note 1: Absolute MaximumRatings indicate limitsbeyond which damageto 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 the GND pin, unless otherwise specified. Note 3: Total unadjusted error includes offset, full-scale, and linearity errors. Note 4: Accuracy may degrade if t

or tRDis shorter than the minimum value specified. See Accuracy vs tWRand Accuracy vs tRDgraphs.

Note 5: When the input voltage (V

) at any pin exceeds the power supply rails (V

V−or V

V+) the absolute value of current at that pin should be limited

to 1 mA or less. The 4 mA package input current limits the number of pins that can exceed the power supply boundaries witha1mAcurrent limit to four.

Note 6: Typicals are at 25˚C and represent most likely parametric norm. Note 7: Tested limits are guaranteed to National’s AOQL (Average Outgoing Quality Level). Note 8: Design limits are guaranteed but not 100% tested. These limits are not used to calculate outgoing quality levels. Note 9: Human body model, 100 pF discharaged through a 1.5 kΩ resistor.

ADC0820

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TRI-STATE Test Circuits and Waveforms

Timing Diagrams

DS005501-3

DS005501-4

tr=20 ns

DS005501-5

DS005501-6

tr=20 ns

DS005501-7

Note: On power-up the state of INT can be high or low.

FIGURE 2. RD Mode (Pin 7 is Low)

ADC0820

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Timing Diagrams (Continued)

DS005501-8

FIGURE 3. WR-RD Mode (Pin 7 is High and t

tI)

DS005501-9

FIGURE 4. WR-RD Mode (Pin 7 is High and t

tI)

DS005501-10

FIGURE 5. WR-RD Mode (Pin 7 is High)

Stand-Alone Operation

ADC0820

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