NSC ADC10664CIN Datasheet

ADC10662/ADC10664
10-Bit 360 ns A/D Converter with Input Multiplexer and
Sample/Hold

General Description

Using an innovative, patented multistep*conversion tech­nique, the 10-bit ADC10662 and ADC10664 are 2- and
4-input CMOS analog-to-digital converters offering
sub-microsecond conversion times yet dissipating a maxi­mum of only 235 mW. The ADC10662 and ADC10664 per­form a 10-bit conversion in two lower-resolution “flashes”,
thus yielding a fast A/D without the cost, power dissipation,
and other problems associated with true flash approaches.
In addition to standard static performance specifications
(Linearity,Full-Scale Error, etc.) dynamic performance (THD,
S/N) is guaranteed.

The analog input voltage tothe ADC10662 and ADC10664 is
sampled and held by an internal sampling circuit. Input sig­nals at frequencies from dc to over 250 kHz can therefore be
digitized accurately without the need for an external
sample-and-hold circuit.

The ADC10662 and ADC10664 include a “speed-up” pin.
Connecting an external resistor between this pin and ground
reduces the typical conversion time to as little as 360 ns.

For ease of interface to microprocessors, theADC10662 and
ADC10664 have been designed to appear as a memory
location or I/O port without the need for external interface
logic.

Features

n Built-in sample-and-hold
n Single +5V supply
n 2- or 4-input multiplexer options
n No external clock required

Key Specifications

n Conversion time to 10 bits: 360 ns typical, 466 ns

max over temperature

n Sampling Rate: 1.5 MHz (min)
n Low power dissipation: 235 mW (max)
n Total harmonic distortion (50 kHz): −60 dB (max)
n No missing codes over temperature

Applications

n Digital signal processor front ends
n Instrumentation
n Disk drives
n Mobile telecommunications

Ordering Information

ADC10662

Industrial

(−40˚C ≤ T

A

≤ +85˚C)

Package

ADC10662CIWM M24B Small Outline

ADC10664

Industrial

(−40˚C ≤ T

A

≤ +85˚C)

Package

ADC10664CIWM M28B Small Outline

*

U.S. Patent Number 4918449

TRI-STATE

®

is a registered trademark of National Semiconductor Corporation.

November 2001

ADC10662/ADC10664 10-Bit 360 ns A/D Converter with Input Multiplexer and Sample/Hold

© 2001 National Semiconductor Corporation DS011192 www.national.com

Simplified Block Diagram

01119209

*ADC10664 Only

Connection Diagrams

01119210

Top View

01119211

Top View

ADC10662/ADC10664

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Pin Descriptions

DVCC,AV

CC

These are the digital and analog positive sup­ply voltage inputs. They should always be
connected to the same voltage source, but
are brought out separately to allow for sepa­rate bypass capacitors. Each supply pin
should be bypassed with a 0.1 µF ceramic
capacitor in parallel with a 10 µF tantalum
capacitor to ground.

INT

This is the active low interrupt output. INT
goes low at the end of each conversion, and
returns to a high state following the rising
edge of RD .

S/H This is the Sample/Hold control input. When

this pin is forced low (and CS is low), it
causes the analog input signal to be sampled
and initiates a new conversion.

RD

This is the active low Read control input.
When this RD and CS are low, any data
present in the output registers will be placed
on the data bus.

CS

This is the active low Chip Select control in­put. When low, this pin enables the RD and S
/H pins.

S0, S1 These pins select the analog input that will be

connected to the A/D during the conversion.
The input is selected based on the state of S0
and S1 when S /H makes its High-to-Low
transition (See the Timing Diagrams). The
ADC10664 includes both S0 and S1. The
ADC10662 includes just S0.

V

REF−

,V

REF+

These are the reference voltage inputs. They
may be placed at any voltage between GND

and V

CC

, but V

REF+

must be greater than

V

REF−

. An input voltage equal to V

REF−

pro­duces an output code of 0, and an input volt­age equal to (V

REF+

− 1 LSB) produces an

output code of 1023.

V

IN0,VIN1

,V

IN2,VIN3

These are the analog input pins. The
ADC10662 has two inputs (V

IN0

and V

IN1

)

and the ADC10664 has four inputs (V

IN0

,

V

IN1,VIN2

and V

IN3

). The impedance of the
source should be less than 500Ω for best
accuracy and conversion speed. For accurate
conversions, no input pin (even one that is
not selected) should be driven more than
50 mV above V

CC

or 50 mV below ground.

GND, AGND, DGND

These are the power supply ground pins. The
ADC10662 and ADC10664 have separate
analog and digital ground pins (AGND and
DGND) for separate bypassing of the analog
and digital supplies. The ground pins should
be connected to a stable, noise-free system
ground. Both pins should be returned to the
same potential.

DB0–DB9 These are the TRI-STATE output pins.
SPEED ADJ

By connecting a resistor between this pin and
ground, the conversion time can be reduced.
The specifications listed in the table of Elec­trical Characteristics apply for a speed adjust
resistor (R

SA

) equal to 14.0 kΩ (Mode 1) or

8.26 kΩ (Mode 2). See the Typical Perfor­mance Curves and the table of Electrical
Characteristics.

ADC10662/ADC10664

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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

+

=AVCC=DVCC) −0.3V to +6V

Voltage at Any Input or Output −0.3V to V

+

+ 0.3V
Input Current at Any Pin (Note 3) 5 mA
Package Input Current (Note 3) 20 mA
Power Dissipation (Note 4) 875 mW
ESD Susceptability (Note 5) 2000V
Soldering Information (Note 6)

N Package (10 Sec) 260˚C
SO Package:

Vapor Phase (60 Sec) 215˚C

Infrared (15 Sec) 220˚C
Storage Temperature Range −65˚C to +150˚C
Junction Temperature 150˚C

Operating Ratings (Notes 1, 2)

Temperature Range T

MIN

≤ TA≤ T

MAX

ADC10662CIN, ADC10662CIWM,
ADC10664CIN,
ADC10664CIWM −40˚C ≤ T

A

≤

+85˚C

Supply Voltage Range 4.5V to 5.5V

Converter Characteristics

The following specifications apply for V+= +5V, V

REF(+)

= +5V, V

REF(−)

= GND, and Speed Adjust pin connected to ground

through a 14.0 kΩ resistor (Mode 1) or an 8.26 kΩ resistor (Mode 2) unless otherwise specified. Boldface limits apply for T

A

=TJ=T

Min

to T

Max

; all other limits TA=TJ= +25˚C.

Symbol Parameter Conditions Typical Limit Units

(Note 7) (Note 8) (Limit)
Resolution 10 Bits
Integral Linearity Error

±

0.5

±

1.0/±1.5 LSB

Offset Error

±

1.5 LSB (max)

Full-Scale Error

±

1 LSB (max)

Total Unadjusted Error

±

0.5

±

1.5/±2.2 LSB
Missing Codes 0 (max)
Power Supply Sensitivity V

+

=5V±5%, V

REF

= 4.5V

±

1/16 LSB

V

+

=5V±10%, V

REF

= 4.5V

±

1

⁄

8

LSB

THD Total Harmonic Distortion (Note 10) f

IN

= 1 kHz, 4.85 V

P-P

−68 dB

f

IN

= 50 kHz, 4.85 V

P-P

−66 −60 dB (max)

f

IN

= 100 kHz, 4.85 V

P-P

−62 dB

f

IN

= 240 kHz, 4.85 V

P-P

−58 dB

SNR Signal-to-Noise Ratio (Note 10) f

IN

= 1 kHz, 4.85 V

P-P

61 dB

f

IN

= 50 kHz, 4.85 V

P-P

60 58 dB (min)

f

IN

= 100 kHz, 4.85 V

P-P

60 dB

ENOB Effective Number of Bits (Note 10) f

IN

= 1 kHz, 4.85 V

P-P

9.6 Bits

f

IN

= 50 kHz, 4.85 V

P-P

9.5 9 Bits (min)

R

REF

Reference Resistance 650 400 Ω (min)

900 Ω (max)

V

REF(+)

V

REF(+)

Input Voltage V++ 0.05 V (max)

V

REF(−)

V

REF(−)

Input Voltage GND − 0.05 V (min)

V

REF(+)

V

REF(+)

Input Voltage V

REF(−)

V (min)

V

REF(−)

V

REF(−)

Input Voltage V

REF(+)

V (max)

V

IN

Input Voltage V++ 0.05 V (max)

V

IN

Input Voltage GND − 0.05 V (min)
OFF Channel Input Leakage Current CS = V

+

,VIN=V

+

0.01 3 µA (max)

ON Channel Input Leakage Current CS = V

+

,VIN=V

+

±

1 −3 µA (max)

ADC10662/ADC10664

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DC Electrical Characteristics

The following specifications apply for V+= +5V, V

REF(+)

=5VV

REF(−)

= GND, and Speed Adjust pin connected to ground

through a 14.0 kΩ resistor (Mode 1) or an 8.26 kΩ resistor (Mode 2) unless otherwise specified. Boldface limits apply for T

A

=TJ=T

MIN

to T

MAX

; all other limits TA=TJ= +25˚C.

Symbol Parameter Conditions

Typical

(Note 7)

Limit

(Note 8)

Units

(Limits)

V

IN(1)

Logical “1” Input Voltage V+= 5.5V 2.0 V (min)

V

IN(0)

Logical “0” Input Voltage V+= 4.5V 0.8 V (max)

I

IN(1)

Logical “1” Input Current V

IN(1)

= 5V 0.005 3.0 µA (max)

I

IN(0)

Logical “0” Input Current V

IN(0)

0V −0.005 −3.0 µA (max)

V

OUT(1)

Logical “1” Output Voltage V+= 4.5V, I

OUT

= −360 µA 2.4 V (min)

V

+

= 4.5V, I

OUT

= −10 µA 4.25 V (min)

V

OUT(0)

Logical “0” Output Voltage V+= 4.5V, I

OUT

= 1.6 mA 0.4 V (max)

I

OUT

TRI-STATE®Output Current V

OUT

= 5V 0.1 50 µA (max)

V

OUT

= 0V −0.1 −50 µA (max)

DI

CC

DVCCSupply Current CS = S /H = RD = 0 1.0 2 mA (max)

AI

CC

AVCCSupply Current CS = S /H = RD = 0 30 45 mA (max)

AC Electrical Characteristics

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

REF(+)

= 5V, V

REF(−)

= GND, and Speed Adjust pin connected

to ground through a 14.0 kΩ resistor (Mode 1) or an 8.26 kΩ resistor (Mode 2) unless otherwise specified. Boldface limits ap-

ply for T

A=TJ=TMIN

to T

MAX

; all other limits TA=TJ= +25˚C.

Symbol Parameter Conditions

Typical

(Note 7)

Limit

(Note 8)

Units

(Limits)

t

CONV

Mode 1 Conversion Time
from Rising Edge of S /H
to Falling Edge of INT

360 466 ns (max)

t

CRD

Mode 2 Conversion Time 470 610 ns (max)

t

ACC1

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

Mode 1; CL= 100 pF

30 50 ns (max)

t

ACC2

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

Mode 2; CL= 100 pF

475 616 ns (max)

t

SH

Minimum Sample Time Mode 1

(Figure 1

) ; (Note 9) 150 ns (max)

t

1H,t0H

TRI-STATE Control (Delay
from Rising Edge of RD
to High-Z State)

R

L

= 1k, CL=10pF

30 60 ns (max)

t

INTH

Delay from Rising Edge of RD
to Rising Edge of INT

CL= 100 pF

25 50 ns (max)

t

P

Delay from End of Conversion
to Next Conversion

50 ns (max)

t

MS

Multiplexer Control Setup Time 10 75 ns (max)

t

MH

Multiplexer Hold Time 10 40 ns (max)

C

VIN

Analog Input Capacitance 35 pF (max)

C

OUT

Logic Output Capacitance 5 pF (max)

C

IN

Logic Input Capacitance 5 pF (max)

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

Note 2: All voltages are measured with respect to GND, unless otherwise specified.
Note 3: When the input voltage (V

IN

) at any pin exceeds the power supply rails (V

IN

<

GND or V

IN

>

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

to 5 mA or less. The 20 mA package input current limits the number of pins that can safely exceed the power supplies with an input current of 5 mA to four.
Note 4: 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. In most cases,

the maximum derated power dissipation will be reached only during fault conditions. For these devices, T

JMAX

for a board-mounted device can be found from the

tables below:

ADC10662/ADC10664

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