Maxim MX7824BQ, MX7824KCAG, MX7824KCWG, MX7824KEAG, MX7824KN Datasheet

19-0255; Rev 2; 4/94

CMOS, High-Speed, 8-Bit ADCs

with Multiplexer

_______________General Description

The MAX154/MAX158 and MX7824/MX7828 are high­speed, multi-channel analog-to-digital converters
(ADCs). The MAX154 and MX7824 have four analog
input channels, while the MAX158 and MX7828 have
eight channels. Conversion time for all devices is 2.5µs.
The MAX154/MAX158 also feature a 2.5V on-chip refer­ence, forming a complete high-speed data acquisition
system.

All four converters include a built-in track/hold, eliminat­ing the need for an external track/hold with many input
signals. The analog input range is 0V to +5V, although
the ADC operates from a single +5V supply.

Microprocessor interfaces are simplified by the ADC’s
ability to appear as a memory location or I/O port without
the need for external logic. The data outputs use latched,
three-state buffer circuitry to allow direct connection to a
microprocessor data bus or system input port.

The MX7824 and MX7828 are pin compatible with
Analog Devices’ AD7824 and AD7828. The MAX154
and MAX158, which feature internal references, are also
compatible with these products.

________________________Applications

Digital Signal Processing
High-Speed Data Acquisition
Telecommunications
High-Speed Servo Control
Audio Instrumentation

____________________________Features

♦ One-Chip Data Acquisition System
♦ Four or Eight Analog Input Channels
♦ 2.5µs per Channel Conversion Time
♦ Internal 2.5V Reference (MAX154/MAX158 only)
♦ Built-In Track/Hold Function

1

LSB Error Specification

/

♦

2

♦ Single +5V Supply Operation
♦ No External Clock
♦ New Space-Saving SSOP Package

______________Ordering Information

PART

MX7824LN

MX7824KN
MX7824LCWG 0°C to +70°C

MX7824KCWG
MX7824LCAG
MX7824KCAG 0°C to +70°C

TEMP. RANGE PIN-PACKAGE

0°C to +70°C

0°C to +70°C

24 Narrow
Plastic DIP

24 Narrow
Plastic DIP

24 Wide SO
0°C to +70°C 24 Wide SO
0°C to +70°C

24 SSOP

24 SSOP

Ordering Information continued on last page.

ERROR

(LSB)

1

±

/

±1

1

±

/

±1

1

/

±

±1

__________________________________________________________Pin Configurations

MX7824/MX7828

2

2

2

TOP VIEW

AIN4

1

AIN3

2

AIN2

3

AIN1

4

TP (REF OUT)

DB0
DB1
DB2

DB3

GND

( ) ARE FOR MAX154/MAX158 ONLY.

5
6
7
8
9

RD

10

INT

11
12

MAX154
MX7824

DIP/SO/SSOP

V

DD

24

NC

23

A0

22

A1

21

DB7

20

DB6

19

DB5

18

DB4

17

CS

16

RDY

15

+

V

14

REF

V

-

13

REF

________________________________________________________________

AIN6
AIN5
AIN4
AIN3
AIN2
AIN1

TP (REF OUT)

DB0
DB1
DB2

DB3

GND

1
2
3
4
5
6
7
8

9
10
11

RD

12

INT

13
14

MAX158
MX7828

DIP/SO/SSOP

Maxim Integrated Products

Call toll free 1-800-998-8800 for free samples or literature.

AIN7

28

AIN8

27

V

26

DD

A0

25

A1

24

A2

23

DB7

22

DB6

21

DB5

20

DB4

19

CS

18

RDY

17

V

+

16

REF

V

-

15

REF

1

CMOS, High-Speed, 8-Bit ADCs
with Multiplexer

ABSOLUTE MAXIMUM RATINGS

Supply Voltage, VDD to GND........................................0V, +10V

Voltage at Any Other Pins......................GND - 0.3V, V

Output Current (REF OUT)..................................................30mA

Power Dissipation (any package) to +75°C ....................450mW

Derate above +25°C by..............................................6mW/°C

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

DD

+ 0.3V

ELECTRICAL CHARACTERISTICS

(VDD= +5V, V

MX7824/MX7828

ACCURACY

Resolution 8 Bits
Total Unadjusted Error (Note 1)
No Missing Codes Resolution 8 Bits

Channel to Channel Mismatch ±1/4 LSB

REFERENCE INPUT

Reference Resistance 14kΩ
V

+ Input Voltage Range V

REF

V

- Input Voltage Range GND V

REF

REFERENCE OUTPUT—MAX154/MAX158 Only (Note 2)

Output Voltage REF OUT 2.47 2.50 2.53 V
Load Regulation -6 -10 mV
Power-Supply Sensitivity ±1 ±3 mV

Output Noise e
Capacitive Load 0.01 µF

ANALOG INPUT

Analog Input Voltage Range A
Analog Input Capacitance C
Analog Input Current I
Slew Rate, Tracking SR 0.7 0.157 V/µs

LOGIC INPUTS (–R—D–, –C—S–, A0, A1, A2)

Input High Voltage V
Input Low Voltage V
Input High Current I
Input Low Current I
Input Capacitance (Note 4) C

+ = +5V, V

REF

PARAMETER SYMBOL MIN TYP MAX UNITS

- = GND, Mode 0, TA= T

REF

N

INR
AIN

AIN

INH

INL
INH
INL

IN

MIN

MAX15_A, MX782_L/C/U

TA= +25°C
IL= 0mA to 10mA, TA= +25°C
VDD±5%, TA= +25°C
MAX15_C
MAX15_E
MAX15_M

Any channel, AIN = 0V to 5V

Operating Temperature Ranges
MX7824, MX7828

KN/LN/KCW_/LCW_............................................0°C to +70°C

BQ/CQ .............................................................-40°C to +85°C

TQ/UQ............................................................-55°C to +125°C

Storage Temperature Range.............................-65°C to +160°C

Lead Temperature (soldering, 10sec).............................+300°C

to T

, unless otherwise noted.)

MAX

CONDITIONS

-VDDV

REF

40 70
40 70Temperature Drift (Note 3)
60 100

200 µV/rms

V

-V

REF

2.4 V

45 pF

58pF

±1/2

±1MAX15_B, MX782_K/B/T

+ V

REF

ppm/°C

+ V

REF

±3 µA

0.8 V
1 µA

-1 µA

LSB

2 _______________________________________________________________________________________

CMOS, High-Speed, 8-Bit ADCs

with Multiplexer

ELECTRICAL CHARACTERISTICS

(VDD= +5V, V

LOGIC OUTPUTS

Output High Voltage
Output Low Voltage

Output Capacitance (Note 4)

POWER SUPPLY

Supply Voltage
Supply Current

Note 1: Total unadjusted error includes offset, full-scale, and linearity errors.
Note 2: Specified with no external load unless otherwise noted.
Note 3: Temperature drift is defined as change in output voltage from +25°C to T
Note 4: Guaranteed by design.

+ = +5V, V

REF

- = GND, Mode 0, TA= T

REF

DB0–DB7, –I—N—T–; I

OH

DB0–DB7, –I—N—T–; RDY

V

OL

DB0–DB7, RDY; V

OUT

5V ±5% for specified performance

DD

–C—S–= –R—D–

DD

VDD= ±5%

MIN

= 2.4V

to T

, unless otherwise noted.)

MAX

CONDITIONS

= -360µA

OUT

I

= 1.6mA

OUT

I

= 2.6mA

OUT

= 0V to V

OUT

DD

MIN

or T

MAX

divided by (25 - T

MIN

TIMING CHARACTERISTICS (Note 5)

(VDD= +5V, V

–C—S–

to –R—D–Setup Time

–C—S–

to –R—D–Hold Time

Multiplexer Address
Setup Time

Multiplexer Address
Hold Time

–C—S–

to RDY Delay
Conversion Time (Mode 0)
Data Access Time After –R—D
Data Access Time

After –I—N—T–, Mode 0
–R—D–

to –I—N—T–Delay (Mode 1)
Data Hold Time
Delay Time

Between Conversions
–R—D–

Pulse Width (Mode 1)

Note 5: All input control signals are specified with t
Note 6: Measured with load circuits of Figure 1 and defined as the time required for an output to cross 0.8V or 2.4V.
Note 7: Defined as the time required for the data lines to change 0.5V when loaded with the circuits of Figure 2.

+ = +5V, V

REF

- = GND, Mode 0, TA= T

REF

SYMBOLPARAMETER

t

CSS

t

CSH

t

AS

t

AH

t

t

–

t

ACC1

t

ACC2

t

CL= 50pF, RL= 5kΩ

RDY
CRD

(Note 6)
(Note 6)
CL= 50pF

INTH

(Note 7)

t

DH

t

P

t

RD

to T

MIN

CONDITIONS

, unless otherwise noted.)

MAX

TA= +25°C

MAX15_ _C/E

MX782_K/L/B/C

MAX15_ _M

MX782_T/U

MIN MAX MIN MAXMIN TYP MAX

0
0

0

30

30 40

1.6 2.0

20 50
40 75

500

60 600

= tF= 20ns (10% to 90% of +5V) and timed from a 1.6V voltage level.

R

0
0

0

35

60

2.4

85

110

60

100

60

70

500

80 500 80 400

0
0

0

40

600

0.4

0.4

) or (T

60

2.8

120

70

100

70

MAX

MX7824/MX7828

UNITSMIN TYP MAXSYMBOLPARAMETER

V4.0V
V

µA±3Three-State Output Current
pF58C

V4.75 5.25V

mA15I
mW25 75Power Dissipation
LSB±1/16 ±1/4PSSPower-Supply Sensitivity

- 25).

UNITS

ns
ns

ns

ns
ns

µs
ns

ns
ns

ns
ns
ns

_______________________________________________________________________________________ 3

CMOS, High-Speed, 8-Bit ADCs



with Multiplexer

__________________________________________Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.)

REFERENCE TEMPERATURE

DRIFT (MAX154/MAX158 ONLY)

2.520

2.510

2.500

REF OUT VOLTAGE (V)

2.490



MX7824/MX7828

2.480

-50 150

050

AMBIENT TEMPERATURE (°C)

LINEARITY ERROR (LSB)

100

ACCURACY vs. V

(V

2.0

1.5

1.0

0.5

0

REF

05

OUTPUT CURRENT

20

MX7824/28-1

16

12

8

OUTPUT CURRENT (mA)

4

0



= V

REF

+ - V

REF

REF

3412

V

(V)

REF

vs. TEMPERATURE

VDD = 5V

I

I

SINK VOUT

-100 150

-50 0 50

AMBIENT TEMPERATURE (°C)



-)

V

= 5V

DD

MX7824/28-4





SOURCE VOUT

= 0.4V

ACCURACY vs. DELAY BETWEEN

2.0

MX7824/28-2

= 2.4V

100

POWER-SUPPLY CURRENT vs. TEMPERATURE

(NOT INCLUDING REFERENCE LADDER)

8

7

6

5

4

– SUPPLY CURRENT (mA)

DD

I

3

2

-100 150

1.5

1.0

LINEARITY ERROR (LSB)

0.5

0

V

= 4.75V

DD

AMBIENT TEMPERATURE (°C)

CONVERSIONS (tp)

300 900



V

= 5.25V

DD



V



50 100-50 0

V

= 5V

DD

V

REF

700 800400 500 600

tp (ns)

MX7824/28-5

= 5V

DD



= 5V

MX7824/28-3

+5V

3k

DBN

3k

100pF

DGND

a. High-Z to V

Figure 1. Load Circuits for Data-Access Time Test

OH

DBN

100pF

b. High-Z to V

DGND

DBN

3k

10pF

DBN

DGND

OL

a. V

High-Z b. V

OH to

Figure 2. Load Circuits for Data-Hold Time Test

4 _______________________________________________________________________________________

+5V

OL to

3k

10pF

DGND

High-Z