19-0255; Rev 2; 4/94
CMOS, High-Speed, 8-Bit ADCs
with Multiplexer
_______________General Description
The MAX154/MAX158 and MX7824/MX7828 are high-
speed, 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 refer-
ence, forming a complete high-speed data acquisition
system.
All four converters include a built-in track/hold, eliminat-
ing 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.
____________________________Features
o
One-Chip Data Acquisition System
o
Four or Eight Analog Input Channels
o
2.5µs per Channel Conversion Time
o
Internal 2.5V Reference (MAX154/MAX158 only)
o
Built-In Track/Hold Function
o
1/2
LSB Error Specification
o
Single +5V Supply Operation
o
No External Clock
o
New Space-Saving SSOP Package
MX7824/MX7828
______________Ordering Information
PART
MX7824LN
MX7824KN
MX7824LCWG
MX7824KCWG
MX7824LCAG
MX7824KCAG
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
PIN-PACKAGE
24 Narrow
Plastic DIP
24 Narrow
Plastic DIP
24 Wide SO
24 Wide SO
24 SSOP
24 SSOP
ERROR
(LSB)
±
1/2
±1
±
1/2
±1
±
1/2
±1
________________________Applications
Digital Signal Processing
High-Speed Data Acquisition
Telecommunications
High-Speed Servo Control
Audio Instrumentation
Ordering Information continued on last page.
__________________________________________________________Pin Configurations
TOP VIEW
AIN6 1
AIN4 1
AIN3 2
AIN2 3
AIN1 4
TP (REF OUT) 5
DB0 6
DB1 7
DB2 8
DB3 9
RD 10
INT 11
GND 12
24 V
DD
23 NC
22 A0
21 A1
AIN5 2
AIN4 3
AIN3 4
AIN2 5
AIN1 6
TP (REF OUT) 7
DB0 8
DB1 9
DB2 10
DB3 11
RD 12
INT 13
GND 14
28 AIN7
27 AIN8
26 V
DD
25 A0
MAX158
MX7828
24 A1
23 A2
22 DB7
21 DB6
20 DB5
19 DB4
18 CS
17 RDY
16 V
REF
+
15 V
REF
-
MAX154
MX7824
20 DB7
19 DB6
18 DB5
17 DB4
16 CS
15 RDY
14 V
REF
+
13 V
REF
-
DIP/SO/SSOP
DIP/SO/SSOP
( ) ARE FOR MAX154/MAX158 ONLY.
________________________________________________________________
Maxim Integrated Products
1
Call toll free 1-800-998-8800 for free samples or literature.
CMOS, High-Speed, 8-Bit ADCs
with Multiplexer
MX7824/MX7828
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, VDD to GND ........................................0V, +10V
Voltage at Any Other Pins......................GND - 0.3V, V
DD
+ 0.3V
Output Current (REF OUT)..................................................30mA
Power Dissipation (any package) to +75°C ....................450mW
Derate above +25°C by ..............................................6mW/°C
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
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.
ELECTRICAL CHARACTERISTICS
(V
DD
= +5V, V
REF
+ = +5V, V
REF
- = GND, Mode 0, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
PARAMETER
ACCURACY
Resolution
Total Unadjusted Error (Note 1)
No Missing Codes Resolution
Channel to Channel Mismatch
REFERENCE INPUT
Reference Resistance
V
REF
+ Input Voltage Range
V
REF
- Input Voltage Range
REFERENCE OUTPUT—MAX154/MAX158 Only
(Note 2)
Output Voltage
Load Regulation
Power-Supply Sensitivity
Temperature Drift (Note 3)
Output Noise
Capacitive Load
ANALOG INPUT
Analog Input Voltage Range
Analog Input Capacitance
Analog Input Current
A
INR
C
AIN
I
AIN
Any channel, AIN = 0V to 5V
0.7
2.4
0.8
1
-1
5
8
V
REF
-
45
±3
0.157
V
REF
+
V
pF
µA
V/µs
V
V
µA
µA
pF
e
N
REF OUT
T
A
= +25°C
I
L
= 0mA to 10mA, T
A
= +25°C
V
DD
±5%, T
A
= +25°C
MAX15_C
MAX15_E
MAX15_M
2.47
2.50
-6
±1
40
40
60
200
0.01
2.53
-10
±3
70
70
100
µV/rms
µF
ppm/°C
V
mV
mV
1
V
REF
-
GND
4
V
DD
V
REF
+
kΩ
V
V
MAX15_A, MX782_L/C/U
MAX15_B, MX782_K/B/T
8
±1/4
8
±1/2
±1
Bits
LSB
Bits
LSB
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Slew Rate, Tracking
SR
– – ––
— —
LOGIC INPUTS ( RD , CS , A0, A1, A2)
Input High Voltage
Input Low Voltage
Input High Current
Input Low Current
Input Capacitance (Note 4)
V
INH
V
INL
I
INH
I
INL
C
IN
2
_______________________________________________________________________________________
CMOS, High-Speed, 8-Bit ADCs
with Multiplexer
ELECTRICAL CHARACTERISTICS
(V
DD
= +5V, V
REF
+ = +5V, V
REF
- = GND, Mode 0, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
PARAMETER
LOGIC OUTPUTS
Output High Voltage
Output Low Voltage
Three-State Output Current
Output Capacitance (Note 4)
POWER SUPPLY
Supply Voltage
Supply Current
Power Dissipation
Power-Supply Sensitivity
Note 1:
Note 2:
Note 3:
Note 4:
PSS
V
DD
= ±5%
V
DD
I
DD
5V ±5% for specified performance
–– ––
— —
CS = RD = 2.4V
4.75
25
±1/16
5.25
15
75
±1/4
V
mA
mW
LSB
C
OUT
V
OH
V
OL
—–
–—
DB0–DB7, INT; I
OUT
= -360µA
—–
–—
DB0–DB7, INT; RDY
I
OUT
= 1.6mA
I
OUT
= 2.6mA
5
4.0
0.4
0.4
±3
8
V
V
µA
pF
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MX7824/MX7828
DB0–DB7, RDY; V
OUT
= 0V to V
DD
Total unadjusted error includes offset, full-scale, and linearity errors.
Specified with no external load unless otherwise noted.
Temperature drift is defined as change in output voltage from +25°C to T
MIN
or T
MAX
divided by (25 - T
MIN
) or (T
MAX
- 25).
Guaranteed by design.
TIMING CHARACTERISTICS
(Note 5)
(V
DD
= +5V, V
REF
+ = +5V, V
REF
- = GND, Mode 0, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
T
A
= +25°C
MIN
–– ––
—
—
CS to RD Setup Time
–– ––
—
—
CS to RD Hold Time
Multiplexer Address
Setup Time
Multiplexer Address
Hold Time
––
—
CS to RDY Delay
Conversion Time (Mode 0)
––
—
Data Access Time After RD
Data Access Time
—–
–—
After INT, Mode 0
– – —–
—
–—
RD to INT Delay (Mode 1)
Data Hold Time
Delay Time
Between Conversions
––
—
RD Pulse Width (Mode 1)
t
CSS
t
CSH
t
AS
t
AH
t
RDY
t
CRD
t
ACC1
t
ACC2
t
INTH
t
DH
t
P
t
RD
C
L
= 50pF, R
L
= 5kΩ
(Note 6)
(Note 6)
C
L
= 50pF
(Note 7)
500
60
600
20
40
0
0
0
30
30
1.6
40
2.0
85
50
75
60
500
80
500
TYP
MAX
MAX15_ _C/E
MX782_K/L/B/C
MIN
0
0
0
35
60
2.4
110
60
100
70
600
80
400
MAX
MAX15_ _M
MX782_T/U
MIN
0
0
0
40
60
2.8
120
70
100
70
MAX
ns
ns
ns
ns
ns
µs
ns
ns
ns
ns
ns
ns
PARAMETER
SYMBOL
CONDITIONS
UNITS
Note 5:
All input control signals are specified with t
R
= t
F
= 20ns (10% to 90% of +5V) and timed from a 1.6V voltage level.
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.
_______________________________________________________________________________________
3
CMOS, High-Speed, 8-Bit ADCs
with Multiplexer
MX7824/MX7828
__________________________________________Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
REFERENCE TEMPERATURE
DRIFT (MAX154/MAX158 ONLY)
MX7824/28-1
OUTPUT CURRENT
vs. TEMPERATURE
V
DD
= 5V
OUTPUT CURRENT (mA)
16
I
SOURCE
V
OUT
= 2.4V
12
MX7824/28-2
ACCURACY vs. DELAY BETWEEN
CONVERSIONS (tp)
V
DD
= 5V
V
REF
= 5V
1.5
MX7824/28-3
2.520
20
2.0
REF OUT VOLTAGE (V)
2.510
LINEARITY ERROR (LSB)
2.500
1.0
8
I
SINK
V
OUT
= 0.4V
4
2.490
0.5
2.480
-50
0
50
100
150
AMBIENT TEMPERATURE (°C)
0
-100
-50
0
50
100
150
AMBIENT TEMPERATURE (°C)
0
300
400
500
600
t
p
(ns)
700
800
900
ACCURACY vs. V
REF
(V
REF
= V
REF
+ - V
REF
-)
MX7824/28-4
POWER-SUPPLY CURRENT vs. TEMPERATURE
(NOT INCLUDING REFERENCE LADDER)
MX7824/28-5
2.0
V
DD
= 5V
LINEARITY ERROR (LSB)
1.5
8
I
DD
– SUPPLY CURRENT (mA)
7
6
5
4
3
2
V
DD
= 4.75V
V
DD
= 5.25V
1.0
V
DD
= 5V
0.5
0
0
1
2
3
4
5
V
REF
(V)
-100
-50
0
50
100
150
AMBIENT TEMPERATURE (°C)
+5V
3k
DBN
3k
DGND
100pF
DBN
100pF
DGND
DBN
3k
DGND
10pF
DBN
+5V
3k
10pF
DGND
a. High-Z to V
OH
b. High-Z to V
OL
a. V
OH
to High-Z
b. V
OL
to High-Z
Figure 1. Load Circuits for Data-Access Time Test
4
Figure 2. Load Circuits for Data-Hold Time Test
_______________________________________________________________________________________
CMOS, High-Speed, 8-Bit ADCs
with Multiplexer
_____________________________________________________________Pin Descriptions
PIN
NAME
MAX154
MX7824
1
2
3
4
5
6
7
8
9
10
AIN4
AIN3
AIN2
AIN1
REF OUT
TP
DBO
DB1
DB2
DB3
––
—
RD
Analog Input Channel 4
Analog Input Channel 3
Analog Input Channel 2
Analog Input Channel 1
Reference Output (2.5V) for MAX154.
Test point for MX7824. Do not connect.
Three-State Data Output, bit 0 (LSB)
Three-State Data Output, bit 1
Three-State Data Output, bit 2
Three-State Data Output, bit 3
––
—
Read Input. RD controls conversions
and data access. See
Digital Interface
section.
Interrupt Output. INT going low indi-
cates the completion of a conversion.
See
Digital Interface
section.
Ground
Lower Limit of Reference Span. Sets
the zero-code voltage.
Range: GND to V
REF
+.
Upper Limit of Reference Span. Sets
the full-scale input voltage.
Range: V
REF
- to V
DD
.
Ready Output. Open-drain output with
no active pull-up device. Goes low
––
—
when CS goes low and high imped-
ance at the end of a conversion.
––
—
Chip-Select Input. CS must be low for
the device to be selected.
Three-State Data Output, bit 4
Three-State Data Output, bit 5
Three-State Data Output, bit 6
Three-State Data Output, bit 7 (MSB)
Channel Address 1 Input
Channel Address 0 Input
No Connect
Power-Supply Voltage, +5V
19
20
21
22
23
24
25
26
27
28
DB4
DB5
DB6
DB7
A2
A1
A0
V
DD
AIN8
AIN7
FUNCTION
MAX158
MX7828
1
2
3
4
5
6
7
8
9
10
11
12
AIN6
AIN5
AIN4
AIN3
AIN2
AIN1
REF OUT
TP
DB0
DB1
DB2
DB3
––
—
RD
Analog Input Channel 6
Analog Input Channel 5
Analog Input Channel 4
Analog Input Channel 3
Analog Input Channel 2
Analog Input Channel 1
Reference Output (2.5V) for MAX158.
Test point for MX7828. Do not connect.
Three-State Data Output, bit 0 (LSB)
Three-State Data Output, bit 1
Three-State Data Output, bit 2
Three-State Data Output, bit 3
––
—
Read Input. RD controls conversions
and data access. See
Digital Interface
section.
Interrupt Output. INT going low indi-
cates the completion of a conversion.
See
Digital Interface
section.
Ground
Lower Limit of Reference Span. Sets
the zero-code voltage.
Range: GND to V
REF
+.
Upper Limit of Reference Span. Sets
the full-scale input voltage.
Range: V
REF
- to V
DD
.
Ready Output. Open-drain output with
no active pull-up device. Goes low
––
—
when CS goes low and high imped-
ance at the end of a conversion.
––
—
Chip-Select Input. CS must be low for
the device to be selected.
Three-State Data Output, bit 4
Three-State Data Output, bit 5
Three-State Data Output, bit 6
Three-State Data Output, bit 7 (MSB)
Channel Address 2 Input
Channel Address 1 Input
Channel Address 0 Input
Power-Supply Voltage, +5V
Analog Input Channel 8
Analog Input Channel 7
5
PIN
NAME
FUNCTION
MX7824/MX7828
11
12
13
INT
GND
V
REF
-
13
14
15
INT
GND
V
REF
-
14
V
REF
+
16
V
REF
+
15
RDY
16
17
18
19
20
21
22
23
24
––
—
CS
DB4
DB5
DB6
DB7
A1
A0
NC
V
DD
17
RDY
18
––
—
CS
_______________________________________________________________________________________
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