19-1686; Rev 1; 12/10
400ksps/300ksps, Single-Supply, Low-Power,
Serial 10-Bit ADCs with Internal Reference
General Description
The MAX1084/MAX1085 10-bit analog-to-digital convert-
ers (ADCs) combine a high-bandwidth track/hold, a serial
interface with high conversion speed, an internal +2.5V
reference, and low power consumption. The MAX1084
operates from a single +4.5V to +5.5V supply; the
MAX1085 operates from a single +2.7V to +3.6V supply.
The 3-wire serial interface connects directly to
SPI™/QSPI™/MICROWIRE™ devices without external
logic. The devices use an external serial-interface clock to
perform successive-approximation analog-to-digital con-
versions.
Low power combined with ease of use and small pack-
age size make these converters ideal for remote-sensor
and data-acquisition applications, or for other circuits with
demanding power consumption and space requirements.
The MAX1084/MAX1085 are available in 8-pin SO
packages.
These devices are pin-compatible, higher-speed versions
of the MAX1242/MAX1243; for more information, refer to
the respective data sheets.
♦
Single-Supply Operation
+4.5V to +5.5V (MAX1084)
+2.7V to +3.6V (MAX1085)
♦
10-Bit Resolution
♦
400ksps Sampling Rate (MAX1084)
♦
Internal Track/Hold
♦
Internal +2.5V Reference
♦
Low Power: 2.5mA (400ksps)
♦
SPI/QSPI/MICROWIRE 3-Wire Serial Interface
♦
Pin-Compatible, High-Speed Upgrade to
MAX1242/MAX1243
♦
8-Pin SO Package
Features
MAX1084/MAX1085
Ordering Information
PART
MAX1084ACSA+
MAX1084BCSA+
MAX1084AESA+
MAX1084BESA+
MAX1085ACSA+
MAX1085BCSA+
MAX1085AESA+
MAX1085BESA+
TEMP
RANGE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-
PACKAGE
8 SO
8 SO
8 SO
8 SO
8 SO
8 SO
8 SO
8 SO
INL
(LSB)
±1/2
±1
±1/2
±1
±1/2
±1
±1/2
±1
Applications
Portable Data Logging
Data Acquisition
Medical Instruments
Battery-Powered Instruments
Pen Digitizers
Process Control
+Denotes
a lead(Pb)-free/RoHS-compliant package.
Pin Configuration
TOP VIEW
CS
SCLK
Functional Diagram
V
DD
1
7
8
3
CONTROL
LOGIC
INT
CLOCK
+
V
DD
AIN
1
2
8
7
SCLK
CS
DOUT
GND
SHDN
SHDN 3
REF 4
MAX1084
MAX1085
OUTPUT
SHIFT
REGISTER
6
DOUT
6
5
AIN
2
T/H
2.5V
REFERENCE
10-BIT
SAR
SO
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
REF
4
MAX1084
MAX1085
5
GND
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
400ksps/300ksps, Single-Supply, Low-Power,
Serial 10-Bit ADCs with Internal Reference
MAX1084/MAX1085
ABSOLUTE MAXIMUM RATINGS
V
DD
to GND .............................................................-0.3V to +6V
AIN to GND................................................-0.3V to (V
DD
+ 0.3V)
REF to GND ...............................................-0.3V to (V
DD
+ 0.3V)
Digital Inputs to GND...............................................-0.3V to +6V
DOUT to GND............................................-0.3V to (V
DD
+ 0.3V)
DOUT Current ..................................................................±25mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin SO (derate 5.88mW/°C above +70°C) ..............471mW
Operating Temperature Ranges
MAX1084_CSA/MAX1085_CSA.........................0°C to +70°C
MAX1084_ESA/MAX1085_ESA ......................-40°C to +85°C
Storage Temperature Range............................-60°C to +150°C
Lead Temperature (soldering, 10s) ................................+300°C
Soldering Temperature (reflow) ......................................+260°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—MAX1084
(V
DD
= +4.5V to +5.5V, f
SCLK
= 6.4MHz, 50% duty cycle, 16 clocks/conversion cycle (400ksps), 4.7µF capacitor at REF, T
A
= T
MIN
to
T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
DC ACCURACY
(Note 1)
Resolution
Relative Accuracy (Note 2)
Differential Nonlinearity
Offset Error
Gain Error (Note 3)
Gain-Error Temperature
Coefficient
DYNAMIC SPECIFICATIONS
(100kHz sine wave, 2.5V
P-P
, clock = 6.4MHz)
Signal-to-Noise Plus Distortion
Ratio
Total Harmonic Distortion
Spurious-Free Dynamic Range
Intermodulation Distortion
Full-Power Bandwidth
Full-Linear Bandwidth
CONVERSION RATE
Conversion Time (Note 4)
Track/Hold Acquisition Time
Aperture Delay
Aperture Jitter
Serial Clock Frequency
Duty Cycle
ANALOG INPUT
(AIN)
Input Voltage Range
Input Capacitance
V
AIN
0
18
2.5
V
pF
f
SCLK
0.5
40
t
CONV
t
ACQ
10
< 50
6.4
60
2.5
468
µs
ns
ns
ps
MHz
%
SINAD
THD
SFDR
IMD
f
IN1
= 99kHz, f
IN2
=102kHz
-3dB point
SINAD > 58dB
Up to the 5th harmonic
60
-70
70
76
6
350
dB
dB
dB
dB
MHz
kHz
±0.8
INL
DNL
MAX1084A
MAX1084B
No missing codes over temperature
10
±0.5
±1.0
±1.0
±4.0
±3.0
Bits
LSB
LSB
LSB
LSB
ppm/°C
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
400ksps/300ksps, Single-Supply, Low-Power,
Serial 10-Bit ADCs with Internal Reference
ELECTRICAL CHARACTERISTICS—MAX1084 (continued)
(V
DD
= +4.5V to +5.5V, f
SCLK
= 6.4MHz, 50% duty cycle, 16 clocks/conversion cycle (400ksps), 4.7µF capacitor at REF, T
A
= T
MIN
to
T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
INTERNAL REFERENCE
REF Output Voltage
REF Short-Circuit Current
REF Output Tempco
Load Regulation (Note 5)
Capacitive Bypass at REF
DIGITAL INPUTS
(SCLK,
CS, SHDN)
Input High Voltage
Input Low Voltage
Input Hysteresis
Input Leakage
Input Capacitance
DIGITAL OUTPUT
(DOUT)
Output Voltage Low
Output Voltage High
Three-State Leakage Current
Three-State Output Capacitance
POWER SUPPLY
Positive Supply Voltage (Note 6)
Positive Supply Current (Note 7)
Shutdown Supply Current
Power-Supply Rejection
V
DD
I
DD
I
SHDN
PSR
V
DD
= 5.5V
SCLK = V
DD
,
SHDN
= GND
V
DD
= 5V ±10%, midscale input
4.5
2.5
2
±0.5
5.5
4.0
10
±2.0
V
mA
µA
mV
V
OL
V
OH
I
L
C
OUT
I
SINK
= 5mA
I
SOURCE
= 1mA
V
CS
= 5V
V
CS
= 5V
15
4
±10
0.4
V
V
µA
pF
V
INH
V
INL
V
HYST
I
IN
C
IN
V
IN
= 0V or V
DD
15
0.2
±1
3.0
0.8
V
V
V
µA
pF
TC V
REF
0 to 1.0mA output load
4.7
V
REF
T
A
= +25°C
2.48
2.50
30
±15
0.1
2.0
10
2.52
V
mA
ppm/°C
mV/mA
µF
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX1084/MAX1085
ELECTRICAL CHARACTERISTICS—MAX1085
(V
DD
= +2.7V to +3.6V, f
SCLK
= 4.8MHz, 50% duty cycle, 16 clocks/conversion cycle (300ksps), 4.7µF capacitor at REF, T
A
= T
MIN
to
T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
DC ACCURACY
(Note 1)
Resolution
Relative Accuracy (Note 2)
Differential Nonlinearity
Offset Error
Gain Error (Note 3)
Gain-Error Temperature
Coefficient
±1.6
INL
DNL
MAX1085A
MAX1085B
No missing codes over temperature
10
±0.5
±1.0
±1.0
±3.0
±3.0
Bits
LSB
LSB
LSB
LSB
ppm/°C
3
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
_______________________________________________________________________________________
400ksps/300ksps, Single-Supply, Low-Power,
Serial 10-Bit ADCs with Internal Reference
MAX1084/MAX1085
ELECTRICAL CHARACTERISTICS—MAX1085 (continued)
(V
DD
= +2.7V to +3.6V, f
SCLK
= 4.8MHz, 50% duty cycle, 16 clocks/conversion cycle (300ksps), 4.7µF capacitor at REF, T
A
= T
MIN
to
T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
Signal-to-Noise Plus Distortion
Ratio
Total Harmonic Distortion
Spurious-Free Dynamic Range
Intermodulation Distortion
Full-Power Bandwidth
Full-Linear Bandwidth
CONVERSION RATE
Conversion Time (Note 4)
Track/Hold Acquisition Time
Aperture Delay
Aperture Jitter
Serial Clock Frequency
Duty Cycle
ANALOG INPUT
Input Voltage Range
Input Capacitance
INTERNAL REFERENCE
REF Output Voltage
REF Short Circuit Current
REF Output Tempco
Load Regulation (Note 5)
Capacitive Bypass at REF
DIGITAL INPUTS
(SCLK,CS,
SHDN)
Input High Voltage
Input Low Voltage
Input Hysteresis
Input Leakage
Input Capacitance
DIGITAL OUTPUTS
(DOUT)
Output Voltage Low
Output Voltage High
Three-State Leakage Current
Three-State Output Capacitance
POWER SUPPLY
Positive Supply Voltage (Note 6)
Positive Supply Current (Note 7)
Shutdown Supply Current
Power-Supply Rejection
4
V
OL
V
OH
I
L
C
OUT
V
DD
I
DD
I
SHDN
PSR
V
DD
= 3.6V
SCLK = V
DD
,
SHDN
= GND
V
DD
= 2.7V to 3.6V, midscale input
I
SINK
= 5mA
I
SOURCE
= 0.5mA
V
CS
= 3V
V
CS
= 3V
2.7
2.5
2
±0.5
15
3.6
3.5
10
±2.0
V
DD
- 0.5V
±10
0.4
V
V
µA
pF
V
mA
µA
mV
V
INH
V
INL
V
HYST
I
IN
C
IN
V
IN
= 0V or V
DD
15
0.2
±1
2.0
0.8
V
V
V
µA
pF
TC V
REF
0 to 0.75mA output load
4.7
V
REF
T
A
= +25°C
2.48
2.50
15
±15
0.1
2.0
10
2.52
V
mA
ppm/°C
mV/mA
µF
V
AIN
C
IN
0
18
2.5
V
pF
f
SCLK
0.5
40
t
CONV
t
ACQ
10
< 50
4.8
60
3.3
625
µs
ns
ns
ps
MHz
%
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DYNAMIC SPECIFICATIONS
(75kHz sinewave, 2.5V
P-P
, f
SAMPLE
= 300ksps, f
SCLK
= 4.8MHz)
SINAD
THD
SFDR
IMD
f
IN1
= 99kHz, f
IN2
=102kHz
-3dB point
SINAD > 58dB
Up to the 5th harmonic
60
-70
70
76
3
250
dB
dB
dB
dB
MHz
kHz
_______________________________________________________________________________________
400ksps/300ksps, Single-Supply, Low-Power,
Serial 10-Bit ADCs with Internal Reference
TIMING CHARACTERISTICS—MAX1084
(Figures 1, 2, 8, 9; V
DD
= +4.5V to +5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
PARAMETER
SCLK Period
SCLK Pulse-Width High
SCLK Pulse-Width Low
CS
Fall to SCLK Rise Setup
SCLK Rise to
CS
Rise Hold
SCLK Rise to
CS
Fall Ignore
CS
Rise to SCLK Rise Ignore
SCLK Rise to DOUT Hold
SCLK Rise to DOUT Valid
CS
Rise to DOUT Disable
CS
Fall to DOUT Enable
CS
Pulse-Width High
SYMBOL
t
CP
t
CH
t
CL
t
CSS
t
CSH
t
CSO
t
CS1
t
DOH
t
DOV
t
DOD
t
DOE
t
CSW
C
LOAD
= 20pF
C
LOAD
= 20pF
C
LOAD
= 20pF
C
LOAD
= 20pF
100
10
CONDITIONS
MIN
156
62
62
35
0
35
35
10
80
65
65
TYP
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
MAX1084/MAX1085
TIMING CHARACTERISTICS—MAX1085
(Figures 1, 2, 8, 9; V
DD
= +2.7V to +3.6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
PARAMETER
SCLK Period
SCLK Pulse-Width High
SCLK Pulse-Width Low
CS
Fall to SCLK Rise Setup
SCLK Rise to
CS
Rise Hold
SCLK Rise to
CS
Fall Ignore
CS
Rise to SCLK Rise Ignore
SCLK Rise to DOUT Hold
SCLK Rise to DOUT Valid
CS
Rise to DOUT Disable
CS
Fall to DOUT Enable
CS
Pulse-Width High
SYMBOL
t
CP
t
CH
t
CL
t
CSS
t
CSH
t
CSO
t
CS1
t
DOH
t
DOV
t
DOD
t
DOE
t
CSW
C
LOAD
= 20pF
C
LOAD
= 20pF
C
LOAD
= 20pF
C
LOAD
= 20pF
C
LOAD
= 20pF
100
13
CONDITIONS
MIN
208
83
83
45
0
45
45
13
100
85
85
TYP
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Note 1:
Tested at V
DD
= V
DD,MIN
.
Note 2:
Relative accuracy is the deviation of the analog value at any code from its theoretical value after the full-scale range has
been calibrated.
Note 3:
Internal reference, offset, and reference errors nulled.
Note 4:
Conversion time is defined as the number of clock cycles multiplied by the clock period; clock has 50% duty cycle.
Note 5:
External load should not change during conversion for specified accuracy. Guaranteed specification limit of 2mV/mA due to
production test limitation.
Note 6:
Electrical characteristics are guaranteed from V
DD,MIN
to V
DD,MAX
. For operations beyond this range, see
Typical Operating
Characteristics.
Note 7:
MAX1084 tested with 20pF on DOUT and f
SCLK
= 6.4MHz, 0 to 5V. MAX1085 tested with same loads, f
SCLK
= 4.8MHz, 0 to
3V. DOUT = full scale.
_______________________________________________________________________________________
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