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TL/H/10556

ADC1031/ADC1034/ADC1038 10-Bit Serial I/O A/D Converters

with Analog Multiplexer and Track/Hold Function

January 1995

ADC1031/ADC1034/ADC1038 10-Bit Serial

I/O A/D Converters with Analog Multiplexer

and Track/Hold Function

General Description

The ADC1031, ADC1034 and ADC1038 are 10-bit succes-

sive approximation A/D converters with serial I/O. The seri-

al input, for the ADC1034 and ADC1038, controls a single-

ended analog multiplexer that selects one of 4 input chan-

nels (ADC1034) or one of 8 input channels (ADC1038). The

ADC1034 and ADC1038 serial output data can be config-

ured into a left- or right-justified format.

An input track/hold is implemented by a capacitive refer-

ence ladder and sampled-data comparator. This allows the

analog input to vary during the A/D conversion cycle.

Separate serial I/O and conversion clock inputs are provid-

ed to facilitate the interface to various microprocessors.

Applications

Engine control

Process control

Instrumentation

Test equipment

Features

Serial I/O (MICROWIRE

compatible)

Separate asynchronous converter clock and serial data

I/O clock

Analog input track/hold function

Ratiometric or absolute voltage referencing

No zero or full scale adjustment required

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

supply

TTL/MOS input/output compatible

No missing codes

Key Specifications

Resolution 10 bits

Total unadjusted error

1 LSB (max)

Single supply 5V

Power dissipation 20 mW (max)

Max. conversion time (f

3 MHz) 13.7 ms (max)

Serial data exchange time (f

1 MHz) 10 ms (max)

TRI-STATE

is a registered trademark of National Semiconductor Corporation.

MICROWIRE

is a trademark of National Semiconductor Corporation.

Connection Diagrams

Dual-In-Line and SO Packages

TL/H/10556– 4

Top View

ADC1031 In NS Package N08E

TL/H/10556– 3

Top View

ADC1034 In NS Packages

J16A, M16B or N16E

TL/H/10556– 2

Top View

ADC1038 In NS Packages

J20A, M20B or N20A

Ordering Information

Industrial

C Package

ADC1031CIN N08E

ADC1034CIN N16E

ADC1034CIWM M16B

ADC1038CIN N20A

ADC1038CIWM M20B

Military

125

C Package

ADC1034CMJ J16A

ADC1038CMJ J20A

1995 National Semiconductor Corporation RRD-B30M75/Printed in U. S. A.

Summary of content (18 pages)

PAGE 1
ADC1031/ADC1034/ADC1038 10-Bit Serial I/O A/D Converters with Analog Multiplexer and Track/Hold Function General Description Features The ADC1031, ADC1034 and ADC1038 are 10-bit successive approximation A/D converters with serial I/O. The serial input, for the ADC1034 and ADC1038, controls a singleended analog multiplexer that selects one of 4 input channels (ADC1034) or one of 8 input channels (ADC1038). The ADC1034 and ADC1038 serial output data can be configured into a left- or right-justified format.
PAGE 2
Absolute Maximum Ratings (Notes 1 & 3) Operating Ratings (Notes 2 & 3) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications. Temperature Range ADC1031CIN, ADC1034CIN, ADC1034CIWM, ADC1038CIN, ADC1038CIWM ADC1034CMJ, ADC1038CMJ Supply Voltage (VCC) 6.
PAGE 3
Electrical Characteristics (Continued) The following specifications apply for VCC e a 5.0V, VREF e a 4.6V, fS e 700 kHz, and fC e 3 MHz unless otherwise specified. Boldface limits apply for TA e TJ e TMIN to TMAX; all other limits TA e TJ e 25§ C. Symbol Parameter Conditions Typical (Note 8) Limit (Note 9) Units (Limits) DIGITAL AND DC CHARACTERISTICS VIN(1) Logical ‘‘1’’ Input Voltage VCC e 5.25 VDC 2.0 V (min) VIN(0) Logical ‘‘0’’ Input Voltage VCC e 4.75 VDC 0.
PAGE 4
Electrical Characteristics (Continued) The following specifications apply for VCC e a 5.0V, VREF e a 4.6V, fS e 700 kHz, and fC e 3 MHz unless otherwise specified. Boldface limits apply for TA e TJ e TMIN to TMAX; all other limits TA e TJ e 25§ C.
PAGE 5
Typical Performance Characteristics Power Supply Current (ICC) vs CCLK Power Supply Current (ICC) vs Ambient Temperature Reference Current (IREF) vs Ambient Temperature Linearity Error vs CCLK Frequency Linearity Error vs Ambient Temperature Linearity Error vs Reference Voltage Zero Error vs Reference Voltage TL/H/10556 – 5 5
PAGE 6
Test Circuits t1H, t0H DO except ‘‘TRI-STATE’’ Leakage Current TL/H/10556–6 TL/H/10556 – 7 TL/H/10556 – 8 Timing Diagrams DO High to Low State DO Low to High State TL/H/10556–9 DO ‘‘TRI-STATE’’ Rise and Fall Times TL/H/10556 – 10 TL/H/10556 – 11 DO Data Output Timing DI Data Input Timing TL/H/10556–12 TL/H/10556 – 13 6
PAGE 7
Timing Diagrams (Continued) ADC1031 CS High during Conversion TL/H/10556 – 14 ADC1038/ADC1034 CS High during Conversion TL/H/10556 – 15 CCLK continuously enabled 7
PAGE 8
Timing Diagrams (Continued) ADC1038/ADC1034 CS Low Continuously TL/H/10556 – 16 CCLK continuously enabled Multiplexer Address/Channel Assignment Tables ADC1038 MUX Address ADC1034 A2 A1 A0 Analog Channel Selected 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 CH0 CH1 CH2 CH3 CH4 CH5 CH6 CH7 MUX Address A2 A1 A0 Analog Channel Selected X X X X 0 0 1 1 0 1 0 1 CH0 CH1 CH2 CH3 Note: ‘‘X’’ e don’t care 8
PAGE 9
TL/H/10556 – 17 ADC1038 Functional Block Diagram 9
PAGE 10
1.0 Pin Descriptions CCLK The clock applied to this input controls the successive approximation conversion time interval. The clock frequency applied to this input can be between 700 kHz and 4 MHz. SCLK The serial data clock input. The clock applied to this input controls the rate at which the serial data exchange occurs and the analog sampling time available to acquire an analog input voltage.
PAGE 11
An acquisition window of 4.5 SCLK cycles is available to allow the ladder capacitance to settle to the analog input voltage. Any change in the analog voltage before or after the acquisition window will not effect the A/D conversion result. In the most simple case, the ladder’s acquisition time is determined by the Ron (9 kX) of the multiplexer switches, the CS1 (3.5 pF) and the total ladder (CL) and stray (CS2) capacitance (48 pF).
PAGE 12
3.0 Analog Considerations (Continued) External Reference 2.5V Full Scale Power Supply as Reference Input Not Referred to GND TL/H/10556–20 TL/H/10556 – 21 TL/H/10556 – 22 *Current path must still exist from VIN(b) to ground FIGURE 3. Analog Input Options ment also facilitates ratiometric operation and in many cases the chip power supply can be used for transducer power as well as the VREF source. 3.
PAGE 13
Protecting the Analog Inputs TL/H/10556 – 26 Diodes are IN914 TL/H/10556 – 25 Zero-Shift and Span-Adjust (2V s VIN s 4.
PAGE 14
PAGE 15
Physical Dimensions inches (millimeters) Order Number ADC1034CMJ NS Package Number J16A Order Number ADC1038CMJ NS Package Number J20A 15
PAGE 16
Physical Dimensions inches (millimeters) (Continued) Order Number ADC1034CIWM NS Package Number M16B Order Number ADC1038CIWM NS Package Number M20B 16
PAGE 17
Physical Dimensions inches (millimeters) (Continued) Order Number ADC1031CIN NS Package Number N08E Order Number ADC1034CIN NS Package Number N16E 17
PAGE 18
ADC1031/ADC1034/ADC1038 10-Bit Serial I/O A/D Converters with Analog Multiplexer and Track/Hold Function Physical Dimensions inches (millimeters) (Continued) Lit. Ý 101002 Order Number ADC1038CIN NS Package Number N20A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1.