_______________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 2.5s.
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.
________________________Applications
Digital Signal Processing
High-Speed Data Acquisition
Telecommunications
High-Speed Servo Control
Audio Instrumentation
____________________________Features
o
One-Chip Data Acquisition System
o
Four or Eight Analog Input Channels
o
2.5s 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
______________Ordering Information
MX7824/MX7828
CMOS, High-Speed, 8-Bit ADCs
with Multiplexer
________________________________________________________________
Maxim Integrated Products
1
24
23
22
21
20
19
18
17
1
2
3
4
5
6
7
8
V
DD
NC
A0
A1
AIN1
AIN2
AIN3
AIN4
TOP VIEW
DB7
( ) ARE FOR MAX154/MAX158 ONLY.
DB6
DB5
DB4
DB2
DB1
DB0
TP (REF OUT)
16
15
14
13
9
10
11
12
CS
RDY
V
REF
+
V
REF
-
GND
INT
RD
DB3
DIP/SO/SSOP
MAX154
MX7824
28
27
26
25
24
23
22
21
1
2
3
4
5
6
7
8
AIN7
AIN8
V
DD
A0
AIN3
AIN4
AIN5
AIN6
A1
A2
DB7
DB6
DB0
TP (REF OUT)
AIN1
AIN2
20
19
18
17
9
10
11
12
DB5
DB4
CS
RDY
RD
DB3
DB2
DB1
DIP/SO/SSOP
MAX158
MX7828
16
15
13
14
V
REF
+
V
REF
-
GND
INT
__________________________________________________________Pin Configurations
Call toll free 1-800-998-8800 for free samples or literature.
19-0255; Rev 2; 4/94
PART
MX7824
LN
MX7824KN
MX7824LCWG
0C to +70C
0C to +70C
0C to +70C
TEMP. RANGE
PIN-PACKAGE
24 Narrow
Plastic DIP
24 Narrow
Plastic DIP
24 Wide SO
MX7824KCWG
MX7824LCAG
MX7824KCAG
0C to +70C
0C to +70C
0C to +70C
24 Wide SO
24 SSOP
24 SSOP
Ordering Information continued on last page.
ERROR
(LSB)
1/2
1
1/2
1
1/2
1
MX7824/MX7828
CMOS, High-Speed, 8-Bit ADCs
with Multiplexer
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
DD
= +5V, V
REF
+ = +5V, V
REF
- = GND, Mode 0, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
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.
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 +75C ....................450mW
Derate above +25C by ..............................................6mW/C
Operating Temperature Ranges
MX7824, MX7828
KN/LN/KCW_/LCW_ ............................................0C to +70C
BQ/CQ .............................................................-40C to +85C
TQ/UQ............................................................-55C to +125C
Storage Temperature Range .............................-65C to +160C
Lead Temperature (soldering, 10sec) .............................+300C
Input Capacitance (Note 4)
C
IN
5
8
pF
Input Low Voltage
V
INL
0.8
V
Input High Current
I
INH
1
A
Input Low Current
I
INL
-1
A
Analog Input Current
I
AIN
3
A
Slew Rate, Tracking
SR
0.7
0.157
V/s
Input High Voltage
V
INH
2.4
V
Any channel, AIN = 0V to 5V
Output Noise
e
N
200
V/rms
Capacitive Load
0.01
F
Analog Input Voltage Range
A
INR
V
REF
-
V
REF
+
V
Analog Input Capacitance
C
AIN
45
pF
1
MAX15_B, MX782_K/B/T
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
Channel to Channel Mismatch
1/4
LSB
No Missing Codes Resolution
8
Bits
Total Unadjusted Error (Note 1)
1/2
LSB
Reference Resistance
1
4
k
V
REF
+ Input Voltage Range
V
REF
-
V
DD
V
V
REF
- Input Voltage Range
GND
V
REF
+
V
Resolution
8
Bits
Output Voltage
REF OUT
2.47
2.50
2.53
V
Load Regulation
-6
-10
mV
Power-Supply Sensitivity
1
3
mV
40
70
40
70
Temperature Drift (Note 3)
60
100
ppm/C
CONDITIONS
T
A
= +25C
I
L
= 0mA to 10mA, T
A
= +25C
MAX15_A, MX782_L/C/U
V
DD
5%, T
A
= +25C
MAX15_C
MAX15_E
MAX15_M
ACCURACY
REFERENCE INPUT
REFERENCE OUTPUT--MAX154/MAX158 Only (Note 2)
ANALOG INPUT
LOGIC INPUTS (
R
--
D
,
C
--
S
, A0, A1, A2)
ELECTRICAL CHARACTERISTICS
(V
DD
= +5V, V
REF
+ = +5V, V
REF
- = GND, Mode 0, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
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.)
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 +25C to T
MIN
or T
MAX
divided by (25 - T
MIN
) or (T
MAX
- 25).
Note 4:
Guaranteed by design.
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.
MX7824/MX7828
CMOS, High-Speed, 8-Bit ADCs
with Multiplexer
_______________________________________________________________________________________
3
(Note 6)
(Note 6)
C
L
= 50pF, R
L
= 5k
(Note 7)
C
L
= 50pF
CONDITIONS
ns
60
t
DH
Data Hold Time
ns
40
75
t
INTH
R
--
D
to
I
--
N
--
T
Delay (Mode 1)
ns
0
t
CSH
ns
0
t
CSS
C
--
S
to
R
--
D
Setup Time
C
--
S
to
R
--
D
Hold Time
ns
20
50
t
ACC2
Data Access Time
After
I
--
N
--
T
, Mode 0
ns
85
t
ACC1
Data Access Time After
R
--
D
s
1.6
2.0
t
CRD
Conversion Time (Mode 0)
ns
30
40
t
RDY
C
--
S
to RDY Delay
ns
0
t
AS
Multiplexer Address
Setup Time
ns
30
t
AH
Multiplexer Address
Hold Time
UNITS
T
A
= +25C
SYMBOL
PARAMETER
ns
500
t
P
Delay Time
Between Conversions
500
70
100
0
0
60
110
2.4
60
0
35
MAX15_ _C/E
MX782_K/L/B/C
600
70
100
0
0
70
120
2.8
60
0
40
MAX15_ _M
MX782_T/U
MIN
MAX
MIN
MAX
MIN
TYP
MAX
ns
60
600
t
RD
R
--
D
Pulse Width (Mode 1)
80
500
80
400
DB0DB7,
I
--
N
--
T
; I
OUT
= -360A
C
--
S
=
R
--
D
= 2.4V
5V 5% for specified performance
DB0DB7, RDY; V
OUT
= 0V to V
DD
V
DD
= 5%
CONDITIONS
LSB
1/16
1/4
PSS
Power-Supply Sensitivity
V
4.0
V
OH
Output High Voltage
mW
25
75
Power Dissipation
mA
15
I
DD
Supply Current
V
4.75
5.25
V
DD
Supply Voltage
A
3
Three-State Output Current
pF
5
8
C
OUT
Output Capacitance (Note 4)
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
DB0DB7,
I
--
N
--
T
; RDY
0.4
V
0.4
V
OL
Output Low Voltage
I
OUT
= 1.6mA
I
OUT
= 2.6mA
LOGIC OUTPUTS
POWER SUPPLY
MX7824/MX7828
CMOS, High-Speed, 8-Bit ADCs
with Multiplexer
4
_______________________________________________________________________________________
__________________________________________Typical Operating Characteristics
(T
A
= +25C, unless otherwise noted.)
2.520
2.480
-50
150
REFERENCE TEMPERATURE
DRIFT (MAX154/MAX158 ONLY)
2.490
2.510
MX7824/28-1
AMBIENT TEMPERATURE (C)
REF OUT VOLTAGE (V)
2.500
100
0
50
20
0
-100
150
OUTPUT CURRENT
vs. TEMPERATURE
4
12
16
MX7824/28-2
AMBIENT TEMPERATURE (C)
OUTPUT CURRENT (mA)
8
100
-50
0
50
V
DD
= 5V
I
SOURCE
V
OUT
= 2.4V
I
SINK
V
OUT
= 0.4V
2.0
0
300
900
ACCURACY vs. DELAY BETWEEN
CONVERSIONS (tp)
0.5
1.0
1.5
MX7824/28-3
t
p
(ns)
LINEARITY ERROR (LSB)
700
800
400
500
600
V
DD
= 5V
V
REF
= 5V
2.0
0
0
5
ACCURACY vs. V
REF
(V
REF
= V
REF
+ - V
REF
-)
0.5
1.0
1.5
MX7824/28-4
V
REF
(V)
LINEARITY ERROR (LSB)
3
4
1
2
V
DD
= 5V
3k
3k
100pF
DGND
DBN
a. High-Z to V
OH
b. High-Z to V
OL
DBN
+5V
DGND
100pF
3k
3k
10pF
DGND
DBN
a. V
OH
to
High-Z
b. V
OL
to
High-Z
DBN
+5V
DGND
10pF
8
2
-100
150
POWER-SUPPLY CURRENT vs. TEMPERATURE
(NOT INCLUDING REFERENCE LADDER)
3
4
5
6
7
MX7824/28-5
AMBIENT TEMPERATURE (C)
I
DD
SUPPLY CURRENT (mA)
50
100
-50
0
V
DD
= 5.25V
V
DD
= 5V
V
DD
= 4.75V
Figure 1. Load Circuits for Data-Access Time Test
Figure 2. Load Circuits for Data-Hold Time Test
MX7824/MX7828
CMOS, High-Speed, 8-Bit ADCs
with Multiplexer
_______________________________________________________________________________________
5
Reference Output (2.5V) for MAX154.
Test point for MX7824. Do not connect.
REF OUT
TP
5
Three-State Data Output, bit 0 (LSB)
DBO
6
Three-State Data Output, bit 1
DB1
7
Analog Input Channel 1
AIN1
4
Analog Input Channel 2
AIN2
3
PIN
Analog Input Channel 3
AIN3
2
Analog Input Channel 4
AIN4
1
FUNCTION
NAME
_____________________________________________________________Pin Descriptions
Three-State Data Output, bit 2
DB2
8
Three-State Data Output, bit 3
DB3
9
Read Input.
R
--
D
controls conversions
and data access. See
Digital Interface
section.
R
--
D
10
Three-State Data Output, bit 7 (MSB)
DB7
20
Ground
GND
12
Lower Limit of Reference Span. Sets
the zero-code voltage.
Range: GND to V
REF
+.
V
REF
-
13
Interrupt Output. INT going low indi-
cates the completion of a conversion.
See
Digital Interface section.
INT
11
Chip-Select Input.
C
--
S
must be low for
the device to be selected.
C
--
S
16
Three-State Data Output, bit 4
DB4
17
Three-State Data Output, bit 5
DB5
18
Three-State Data Output, bit 6
DB6
19
Interrupt Output. INT going low indi-
cates the completion of a conversion.
See
Digital Interface section.
INT
13
Ground
GND
14
Analog Input Channel 2
AIN2
5
Analog Input Channel 1
AIN1
6
Reference Output (2.5V) for MAX158.
Test point for MX7828. Do not connect.
REF OUT
TP
7
Analog Input Channel 3
AIN3
4
Analog Input Channel 4
AIN4
3
PIN
Analog Input Channel 5
AIN5
2
Analog Input Channel 6
AIN6
1
FUNCTION
NAME
Three-State Data Output, bit 0 (LSB)
DB0
8
Three-State Data Output, bit 1
DB1
9
Three-State Data Output, bit 2
DB2
10
Three-State Data Output, bit 3
DB3
11
Lower Limit of Reference Span. Sets
the zero-code voltage.
Range: GND to V
REF
+.
V
REF
-
15
Read Input.
R
--
D
controls conversions
and data access. See
Digital Interface
section.
R
--
D
12
Ready Output. Open-drain output with
no active pull-up device. Goes low
when
C
--
S
goes low and high imped-
ance at the end of a conversion.
RDY
17
Power-Supply Voltage, +5V
V
DD
26
Channel Address 2 Input
A2
23
Channel Address 1 Input
A1
24
Channel Address 0 Input
A0
25
Upper Limit of Reference Span. Sets
the full-scale input voltage.
Range: V
REF
- to V
DD
.
V
REF
+
14
Ready Output. Open-drain output with
no active pull-up device. Goes low
when
C
--
S
goes low and high imped-
ance at the end of a conversion.
RDY
15
Power-Supply Voltage, +5V
V
DD
24
Channel Address 1 Input
A1
21
Channel Address 0 Input
A0
22
No Connect
NC
23
Three-State Data Output, bit 7 (MSB)
DB7
22
Chip-Select Input.
C
--
S
must be low for
the device to be selected.
C
--
S
18
Three-State Data Output, bit 4
DB4
19
Three-State Data Output, bit 5
DB5
20
Three-State Data Output, bit 6
DB6
21
Analog Input Channel 8
AIN8
27
Analog Input Channel 7
AIN7
28
Upper Limit of Reference Span. Sets
the full-scale input voltage.
Range: V
REF
- to V
DD
.
V
REF
+
16
MAX154
MX7824
MAX158
MX7828
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