NSC ADC08031BIWM, ADC08031BIN, ADC08031CIN, ADC08031BIWMX Datasheet

ADC08031/ADC08032/ADC08034/ADC08038
8-Bit High-Speed Serial I/O A/D Converters with
Multiplexer Options, Voltage Reference, and Track/Hold
Function

General Description

The ADC08031/ADC08032/ADC08034/ADC08038 are 8-bit
successive approximationA/D converters with serial I/O and
configurable input multiplexers with up to 8 channels. The
serial I/O is configured to comply with the NSC MICROW­IRE

™

serial data exchangestandard for easy interface tothe

COPS

™

family of controllers, and can easily interface with

standard shift registers or microprocessors.
TheADC08034 and ADC08038 provide a 2.6V band-gap de-

rived reference. For devices offeringguaranteed voltage ref­erence performance over temperature see ADC08131,
ADC08134 and ADC08138.

Atrack/hold function allowsthe analog voltage at thepositive
input to vary during the actual A/D conversion.

The analog inputs can be configured to operate in various
combinations of single-ended, differential, or
pseudo-differential modes. In addition, input voltage spans
as small as 1V can be accommodated.

Applications

n Digitizing automotive sensors
n Process control monitoring
n Remote sensing in noisy environments
n Instrumentation

n Test systems
n Embedded diagnostics

Features

n Serial digital data link requires few I/O pins
n Analog input track/hold function
n 2-, 4-, or 8-channel input multiplexer options with

address logic

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

supply

n No zero or full scale adjustment required
n TTL/CMOS input/output compatible
n On chip 2.6V band-gap reference
n 0.3" standard width 8-, 14-, or 20-pin DIP package
n 14-, 20-pin small-outline packages

Key Specifications

n Resolution: 8 bits
n Conversion time (f

C

= 1 MHz): 8µs (max)

n Power dissipation: 20mW (max)
n Single supply: 5V

DC

(±5%)

n Total unadjusted error:

±

1

⁄2LSB and±1LSB

n No missing codes over temperature

Ordering Information

Industrial (−40˚C ≤ TA≤ +85˚C) Package

ADC08031CIN* N08E
ADC08038CIN* N20A
ADC08031CIWM,
ADC08032CIWM, M14B
ADC08034CIWM
ADC08038CIWM M20B

*

Not recomended for new designs.

COPS™microcontrollers and MICROWIRE™are trademarks of National Semiconductor Corporation.

June 2000

ADC08031/ADC08032/ADC08034/ADC08038 8-Bit High-Speed Serial I/O A/D Converters with

Multiplexer Options, Voltage Reference, and Track/Hold Function

© 2000 National Semiconductor Corporation DS010555 www.national.com

Connection Diagrams

ADC08038

DS010555-2

ADC08034

DS010555-3

ADC08031

Dual-In-Line Package

DS010555-5

ADC08032

Small Outline Package

DS010555-30

ADC08031

Small Outline Package

DS010555-31

ADC08031/ADC08032/ADC08034/ADC08038

www.national.com 2

Absolute Maximum Ratings (Notes 1, 3)

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

Supply Voltage (V

CC

) 6.5V

Voltage at Inputs and Outputs −0.3V to V

CC

+ 0.3V

Input Current at Any Pin (Note 4)

±

5mA

Package Input Current (Note 4)

±

20 mA

Power Dissipation at T

A

= 25˚C

(Note 5) 800 mW
ESD Susceptibility (Note 6) 1500V
Soldering Information

N Package (10 sec.)

SO Package:

Vapor Phase (60 sec.)
Infrared (15 sec.) (Note 7)

235˚C
215˚C

220˚C

Storage Temperature −65˚C to +150˚C

Operating Ratings (Notes 2, 3)

Temperature Range T

MIN

≤ TA≤ T

MAX

ADC08031BIN, ADC08031CIN, −40˚C ≤ TA≤ +85˚C
ADC08032BIN, ADC08032CIN,
ADC08034BIN, ADC08034CIN,
ADC08038BIN, ADC08038CIN,
ADC08031BIWM, ADC08032BIWM,
ADC08034BIWM, ADC08038BIWM
ADC08031CIWM, ADC08032CIWM,
ADC08034CIWM, ADC08038CIWM
Supply Voltage (V

CC

) 4.5 VDCto 6.3 V

DC

Electrical Characteristics

The following specifications apply for VCC=V

REF

=+5VDC, and f

CLK

= 1 MHz unless otherwise specified. Boldface limits

apply for TA=TJ=T

MIN

to T

MAX

; all other limits TA=TJ= 25˚C.

Symbol Parameter Conditions Typical Limits Units

(Note 8) (Note 9) (Limits)

CONVERTER AND MULTIPLEXER CHARACTERISTICS

Total Unadjusted Error (Note 10)

BIN, BIWM

±

1

⁄

2

LSB (max)

CIN, CIWM

±

1 LSB (max)

Differential 8 Bits (min)
Linearity

R

REF

Reference Input Resistance (Note 11) 3.5 kΩ

1.3 kΩ (min)

6.0 kΩ (max)

V

IN

Analog Input Voltage (Note 12) (VCC+ 0.05) V (max)

(GND − 0.05) V (min)

DC Common-Mode Error

±

1

⁄

4

LSB (max)

Power Supply Sensitivity V

CC

=5V±5%,

±

1

⁄

4

LSB (max)

V

REF

= 4.75V
On Channel Leakage On Channel = 5V, 0.2 µA (max)
Current (Note 13) Off Channel = 0V 1

On Channel = 0V, −0.2 µA (max)

Off Channel = 5V −1
Off Channel Leakage On Channel = 5V, −0.2 µA (max)
Current (Note 13) Off Channel = 0V −1

On Channel = 0V, 0.2 µA (max)

Off Channel = 5V 1

DIGITAL AND DC CHARACTERISTICS

V

IN(1)

Logical “1” Input Voltage VCC= 5.25V 2.0 V (min)

V

IN(0)

Logical “0” Input Voltage VCC= 4.75V 0.8 V (max)

I

IN(1)

Logical “1” Input Current VIN= 5.0V 1 µA (max)

I

IN(0)

Logical “0” Input Current VIN=0V −1 µA (max)

V

OUT(1)

Logical “1” Output Voltage VCC= 4.75V:

I

OUT

= −360 µA 2.4 V (min)

I

OUT

= −10 µA 4.5 V (min)

V

OUT(0)

Logical “0” Output Voltage VCC= 4.75V 0.4 V (max)

I

OUT

= 1.6 mA

ADC08031/ADC08032/ADC08034/ADC08038

www.national.com3

Electrical Characteristics (Continued)

The following specifications apply for VCC=V

REF

=+5VDC, and f

CLK

= 1 MHz unless otherwise specified. Boldface limits

apply for TA=TJ=T

MIN

to T

MAX

; all other limits TA=TJ= 25˚C.

Symbol Parameter Conditions Typical Limits Units

(Note 8) (Note 9) (Limits)

DIGITAL AND DC CHARACTERISTICS

I

OUT

TRI-STATE®Output Current V

OUT

=0V −3.0 µA (max)

V

OUT

=5V 3.0 µA (max)

I

SOURCE

Output Source Current V

OUT

=0V −6.5 mA (min)

I

SINK

Output Sink Current V

OUT=VCC

8.0 mA (min)

I

CC

Supply Current

ADC08031, ADC08034, CS = HIGH

3.0 mA (max)
and ADC08038
ADC08032 (Note 16) 7.0 mA (max)

REFERENCE CHARACTERISTICS

V

REF

OUT Nominal Reference Output V

REF

OUT Option
Available Only on 2.6 V
ADC08034 and

ADC08038

Electrical Characteristics

The following specifications apply for VCC=V

REF

=+5VDC, and tr=tf= 20 ns unless otherwise specified. Boldface limits

apply for TA=TJ=T

MIN

to T

MAX

; all other limits TA=TJ= 25˚C.

Symbol Parameter Conditions Typical Limits Units

(Note 8) (Note 9) (Limits)

f

CLK

Clock Frequency 10 kHz (min)

1 MHz (max)
Clock Duty Cycle 40 % (min)
(Note 14) 60 % (max)

T

C

Conversion Time (Not Including f

CLK

= 1 MHz 8 1/f

CLK

(max)

MUX Addressing Time) 8 µs (max)

t

CA

Acquisition Time

1

⁄

2

1/f

CLK

(max)

t

SELECT

CLK High while CS is High 50 ns

t

SET-UP

CS Falling Edge or Data Input 25 ns (min)
Valid to CLK Rising Edge

t

HOLD

Data Input Valid after CLK 20 ns (min)
Rising Edge

t

pd1,tpd0

CLK Falling Edge to Output CL= 100 pF:
Data Valid (Note 15) Data MSB First 250 ns (max)

Data LSB First 200 ns (max)

t

1H,t0H

TRI-STATE Delay from Rising Edge CL= 10 pF, RL=10kΩ 50 ns
of CS to Data Output and SARS Hi-Z

(see TRI-STATE Test Circuits)
C

L

= 100 pF, RL=2kΩ 180 ns (max)

C

IN

Capacitance of Logic Inputs 5 pF

C

OUT

Capacitance of Logic Outputs 5 pF

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.
Note 2: Operating Ratings indicate conditions for which the device is functional. These ratings do not guarantee specific performance limits. For guaranteed speci-

fications and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed. Some performance character­istics may degrade when the device is not operated under the listed test conditions.

Note 3: All voltages are measured with respect to AGND = DGND = 0 V

DC

, unless otherwise specified.

Note 4: When the input voltage V

IN

at any pin exceeds the power supplies (V

IN

<

(AGND or DGND) or V

IN

>

VCC) the current at that pin should be limited to 5 mA.

The 20 mA maximum package input current rating limits the number of pins that can safely exceed the power supplies with an input current of 5 mA to four pins.
Note 5: The maximum power dissipation must be derated at elevated temperatures and is dictated by T

JMAX

, θJAand the ambient temperature, TA. The maximum

allowable power dissipation at any temperature is P

D

=(T

JMAX−TA

)/θJAor the number given in the Absolute Maximum Ratings, whichever is lower. For these de-

ADC08031/ADC08032/ADC08034/ADC08038

www.national.com 4

Electrical Characteristics (Continued)

vices, T

JMAX

= 125˚C. The typical thermal resistances (θJA) of these parts when board mounted follow: ADC08031 and ADC08032 with BIN and CIN suffixes

120˚C/W,ADC08038withCINsuffix80˚C/W.ADC08031 withCIWMsuffix140˚C/W,ADC08032 140˚C/W, ADC08034 140˚C/W,ADC08038with CIWM suffix 91˚C/W.

Note 6: Human body model, 100 pF capacitor discharged through a 1.5 kΩ resistor.
Note 7: See AN450 “Surface MountingMethods and Their Effect on Product Reliability” or Linear DataBook section “Surface Mount” for other methods of soldering

surface mount devices.
Note 8: Typicals are at T

J

= 25˚C and represent the most likely parametric norm.

Note 9: Guaranteed to National’s AOQL (Average Outgoing Quality Level).
Note 10: Total unadjusted error includes offset, full-scale, linearity, multiplexer.
Note 11: Cannot be tested for the ADC08032.
Note 12: For V

IN(−)

≥ V

IN(+)

the digital code will be 0000 0000. Twoon-chip diodes are tied to each analog input (see Block Diagram) which will forward-conduct for

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

CC

supply.During testing at low VCClevels (e.g., 4.5V), high level analog inputs
(e.g., 5V) can cause an input diode to conduct, especially at elevated temperatures, which willcause errors for analog inputs near full-scale. The spec allows 50 mV
forward bias of either diode; this means that as long as the analog V

IN

does not exceed the supply voltage by more than 50 mV, the output code will be correct. Ex-

ceeding this range on an unselected channelwillcorrupt the reading of a selected channel. Achievement of an absolute 0V

DC

to5VDCinput voltage range will there-

fore require a minimum supply voltage of 4.950 V

DC

over temperature variations, initial tolerance and loading.

Note 13: Channel leakage currentis measured after a single-ended channelis selected and the clock isturned off. For off channel leakage currentthe following two
cases are considered: one, with the selected channel tied high (5 V

DC

) and the remaining seven off channels tied low (0 VDC), total current flow through the off chan­nels is measured; two, withthe selected channel tied low and the off channels tied high, totalcurrent flow through the off channelsis again measured. The two cases
considered for determining on channel leakage current are the same except total current flow through the selected channel is measured.

Note 14: A 40% to 60% dutycycle range insures proper operation at all clock frequencies. In the case that an available clock hasa duty cycle outside of theselimits
the minimum time the clock is high or low must be at least 450 ns. The maximum time the clock can be high or low is 100 µs.

Note 15: Since data, MSB first, istheoutput of the comparator used in the successive approximationloop,an additional delay is built in (see Block Diagram) toallow
for comparator response time.

Note 16: For the ADC08032 V

REF

IN is internally tied to VCC, therefore, for the ADC08032 reference current is included in the supply current.

Typical Performance Characteristics

Linearity Error vs
Reference Voltage

DS010555-32

Linearity Error vs
Temperature

DS010555-33

Linearity Error vs
Clock Frequency

DS010555-34

Power Supply Current vs
Temperature (ADC08038,
ADC08034, ADC08031)

DS010555-35

Note: For ADC08032 add I

REF

Output Current vs
Temperature

DS010555-36

Power Supply Current
vs Clock Frequency

DS010555-37

ADC08031/ADC08032/ADC08034/ADC08038

www.national.com5

Leakage Current Test Circuit

TRI-STATE Test Circuits and Waveforms

Timing Diagrams

DS010555-7

t

1H

DS010555-38

DS010555-39

t

0H

DS010555-40

DS010555-41

Data Input Timing

DS010555-10

*To reset these devices, CLK and CS must be simultaneously high for a period of t

SELECT

or greater. Otherwise these devices are compatible with industry

standards ADC0831/2/4/8.

ADC08031/ADC08032/ADC08034/ADC08038

www.national.com 6

Timing Diagrams (Continued)

Data Output Timing

DS010555-11

ADC08031 Start Conversion Timing

DS010555-12

ADC08031 Timing

DS010555-13

*LSB first output not available on ADC08031.
LSB information is maintained for remainder of clock periods until CS goes high.

ADC08032 Timing

DS010555-14

ADC08031/ADC08032/ADC08034/ADC08038

www.national.com7

Timing Diagrams (Continued)

ADC08034 Timing

DS010555-15

ADC08031/ADC08032/ADC08034/ADC08038

www.national.com 8