19-2231; Rev 3; 8/10
KIT
ATION
EVALU
BLE
AVAILA
150ksps, 12-Bit, 2-Channel Single-Ended, and
1-Channel True-Differential ADCs
General Description
The MAX1286–MAX1289 are low-cost, micropower, seri-
al output 12-bit analog-to-digital converters (ADCs)
available in a tiny 8-pin SOT23 and an 8-pin TDFN. The
MAX1286/MAX1288 operate with a single +5V supply.
The MAX1287/MAX1289 operate with a single +3V sup-
ply. The devices feature a successive-approximation
ADC, automatic shutdown, fast wakeup (1.4µs), and a
high-speed 3-wire interface. Power consumption is only
0.5mW (V
DD
= +2.7V) at the maximum sampling rate of
150ksps. AutoShutdown™ (0.2µA) between conversions
results in reduced power consumption at slower
throughput rates. The MAX1286/MAX1287 provide
2-channel, single-ended operations and accept input
signals from 0 to V
REF
. The MAX1288/MAX1289 accept
true-differential inputs ranging from 0 to V
REF
. Data is
accessed using an external clock through the 3-wire
SPI™-/QSPI™-/MICROWIRE™-compatible serial inter-
face. Excellent dynamic performance, low power, ease
of use, and small package size make these converters
ideal for portable battery-powered data-acquisition
applications, and for other applications that demand low
power consumption and minimal space.
Features
o
Single-Supply Operation
+3V (MAX1287/MAX1289)
+5V (MAX1286/MAX1288)
o
Autoshutdown Between Conversions
o
Low Power
245µA at 150ksps
150µA at 100ksps
15µA at 10ksps
2µA at 1ksps
0.2µA in Shutdown
o
True-Differential Track/Hold, 150kHz Sampling Rate
o
Software-Configurable Unipolar/Bipolar
Conversion (MAX1288/MAX1289 Only)
o
SPI-/QSPI-/MICROWIRE-Compatible Interface for
DSPs and Processors
o
Internal Conversion Clock
o
8-Pin SOT23 and 8-Pin TDFN Packages
MAX1286–MAX1289
Applications
Low-Power Data Acquisition
Portable Temperature Monitors
Flowmeters
Touch Screens
PART
MAX1286EKA-T
MAX1286ETA+T
MAX1287EKA-T
MAX1287ETA+T
Ordering Information
PIN-PACKAGE
8 SOT23
8 TDFN-EP*
8 SOT23
8 TDFN-EP*
8 SOT23
8 TDFN-EP*
8 SOT23
8 TDFN-EP*
TOP MARK
AAFA
+AFR
AAEW
+AFN
AAFC
+AFT
AAEY
+AFP
Pin Configurations
SCLK
DOUT
REF
MAX1288EKA-T
MAX1288ETA+T
MAX1289EKA-T
MAX1289ETA+T
TOP VIEW
8
V
DD
1
AIN1 (AIN+) 2
AIN2 (AIN-)
3
8
7
SCLK
DOUT
CNVST
REF
7
CNVST
6
5
MAX1286–
MAX1289
6
5
MAX1286–
MAX1289
EP
Note:
All devices specified over the -40°C to +85°C operating
range.
+Denotes
a lead(Pb)-free/RoHS-compliant package.
-Denotes
a package containing lead(Pb).
*EP
= Exposed pad.
GND 4
+
1
V
DD
2
AIN1 (AIN+)
3
AIN2 (AIN-)
4
GND
SOT23
( ) ARE FOR THE MAX1288/MAX1289
TDFN
AutoShutdown is a trademark of Maxim Integrated Products, Inc.
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
________________________________________________________________
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.
150ksps, 12-Bit, 2-Channel Single-Ended, and
1-Channel True-Differential ADCs
MAX1286–MAX1289
ABSOLUTE MAXIMUM RATINGS
V
DD
to GND ..............................................................-0.3V to +6V
CNVST, SCLK, DOUT to GND....................-0.3V to (V
DD
+ 0.3V)
REF, AIN1 (AIN+), AIN2 (AIN-) to GND......-0.3V to (V
DD
+ 0.3V)
Maximum Current into Any Pin............................................50mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin SOT23 (derate 9.70mW/°C above T
A
= +70°C) ...696mW
8-Pin TDFN (derate 18.5mW/°C above T
A
= +70°C) ...1481mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-60°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow)
Lead(Pb)-Free Packages...............................................+260°C
Packages Containing Lead(Pb).....................................+240°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
= +2.7V to +3.6V, V
REF
= +2.5V for MAX1287/MAX1289, or V
DD
= +4.75V to +5.25V, V
REF
= +4.096V for MAX1286/MAX1288,
0.1µF capacitor at REF, f
SCLK
= 8MHz (50% duty cycle), AIN- = GND for MAX1288/MAX1289. T
A
= T
MIN
to T
MAX,
unless otherwise
noted. Typical values at T
A
= +25°C.)
PARAMETER
DC ACCURACY
(Note 1)
Resolution
Relative Accuracy (Note 2)
Differential Nonlinearity
Offset Error
Gain Error (Note 3)
Gain Temperature Coefficient
Offset Temperature Coefficient
Channel-to-Channel Offset Matching
Channel-to-Channel Gain Matching
Input Common-Mode Rejection
CMR
V
CM
= 0V to V
DD
; zero scale input
INL
DNL
No missing codes over temperature
±2
±2
±0.4
±0.4
±0.1
±0.1
±0.1
12
±1.0
±1.0
±4
±4
Bits
LSB
LSB
LSB
LSB
ppm/°C
ppm/°C
LSB
LSB
mV
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DYNAMIC SPECIFICATIONS:
(f
IN
(sine-wave) = 10kHz, V
IN
= 4.096Vp-p for MAX1286/MAX1288 or V
IN
= 2.5V
p-p
for MAX1287/MAX1289, 150ksps, f
SCLK
= 8MHz, (50% duty cycle) AIN- = GND for MAX1288/MAX1289)
Signal to Noise Plus Distortion
Total Harmonic Distortion
(up to the 5
th
harmonic)
Spurious-Free Dynamic Range
Full-Power Bandwidth
Full-Linear Bandwidth
CONVERSION RATE
Conversion Time
T/H Acquisition Time
Aperture Delay
Aperture Jitter
Maximum Serial Clock Frequency
Duty Cycle
ANALOG INPUT
Input Voltage Range (Note 4)
Unipolar
Bipolar
0
-V
REF
/2
V
REF
V
REF
/2
V
f
SCLK
8
30
70
t
CONV
t
ACQ
30
<50
Does not include t
ACQ
3.7
1.4
µs
µs
ns
ps
MHz
%
SINAD
THD
SFDR
-3dB point
SINAD > 68dB
70
-82
86
1
100
dB
dB
dB
MHz
kHz
2
_______________________________________________________________________________________
150ksps, 12-Bit, 2-Channel Single-Ended, and
1-Channel True-Differential ADCs
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +2.7V to +3.6V, V
REF
= +2.5V for MAX1287/MAX1289, or V
DD
= +4.75V to +5.25V, V
REF
= +4.096V for MAX1286/MAX1288,
0.1µF capacitor at REF, f
SCLK
= 8MHz (50% duty cycle), AIN- = GND for MAX1288/MAX1289. T
A
= T
MIN
to T
MAX,
unless otherwise
noted. Typical values at T
A
= +25°C.)
PARAMETER
Input Leakage Current
Input Capacitance
EXTERNAL REFERENCE INPUT
Input Voltage Range
V
REF
V
REF
= +2.5V at 150ksps
Input Current
I
REF
V
REF
= +4.096V at 150ksps
Acquisition/Between conversions
DIGITAL INPUTS/OUTPUTS (SCLK, CNVST, DOUT)
Input Low Voltage
Input High Voltage
Input Leakage Current
Input Capacitance
Output Low Voltage
Output High Voltage
Three-State Leakage Current
Three-State Output Capacitance
POWER REQUIREMENTS
Positive Supply Voltage
V
DD
MAX1286/MAX1288
MAX1287/MAX1289
f
SAMPLE
=150ksps
V
DD
= +3V
f
SAMPLE
=100ksps
f
SAMPLE
=10ksps
f
SAMPLE
=1ksps
Positive Supply Current
I
DD
V
DD
= +5V
f
SAMPLE
=150ksps
f
SAMPLE
=100ksps
f
SAMPLE
=10ksps
f
SAMPLE
=1ksps
Shutdown
Positive Supply Rejection
PSR
V
DD
= 5V
±5%;
full-scale input
V
DD
= +2.7V to +3.6V; full-scale input
4.75
2.7
5.0
3.0
245
150
15
2
320
215
22
2.5
0.2
±0.3
±0.4
5
±1.0
±1.2
mV
400
µA
5.25
3.6
350
V
C
OUT
V
IL
V
IH
I
L
C
IN
V
OL
V
OH
I
SINK
= 2mA
I
SINK
= 4mA
I
SOURCE
= 1.5mA
CNVST = GND
CNVST = GND
V
DD
-0.5
±0.05
15
±10
V
DD
-1
±0.01
15
0.4
0.8
±1.0
0.8
V
V
µA
pF
V
V
V
µA
pF
1.0
16
26
±0.01
V
DD
+50mV
30
45
±1
µA
V
SYMBOL
CONDITIONS
Channel not selected or conversion stopped
MIN
TYP
±0.01
34
MAX
±1
UNITS
µA
pF
MAX1286–MAX1289
_______________________________________________________________________________________
3
150ksps, 12-Bit, 2-Channel Single-Ended, and
1-Channel True-Differential ADCs
MAX1286–MAX1289
TIMING CHARACTERISTICS (Figures 1, 2, and 5)
(V
DD
= +2.7V to +3.6V, V
REF
= +2.5V, 0.1µF capacitor at REF, or V
DD
= +4.75V to +5.25V for MAX1286/MAX1288, V
REF
= +4.096V,
0.1µF capacitor at REF, f
SCLK
= 8MHz (50% duty cycle); AIN- = GND for MAX1288/MAX1289. T
A
= T
MIN
to T
MAX,
unless otherwise
noted. Typical values at T
A
= +25°C.)
PARAMETERS
SCLK Pulse Width High
SCLK Pulse Width Low
SCLK Fall to DOUT Transition
SCLK Rise to DOUT Disable
CNVST Rise to DOUT Enable
CNVST Fall to MSB Valid
CNVST Pulse Width
SYMBOL
t
CH
t
CL
t
DOT
t
DOD
t
DOE
t
CONV
t
CSW
C
LOAD
= 30pF
C
LOAD
= 30pF
C
LOAD
= 30pF
C
LOAD
= 30pF
30
100
CONDITIONS
MIN
38
38
60
500
80
3.7
TYP
MAX
UNITS
ns
ns
ns
ns
ns
µs
ns
Note 1:
Unipolar mode.
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:
Offset nulled.
Note 4:
The absolute input voltage range for the analog inputs is from GND to V
DD
.
CNVST
•••
t
CH
t
CL
SCLK
•••
t
CSW
t
DOE
DOUT
HIGH-Z
•••
t
DOT
t
DOD
HIGH-Z
Figure 1. Detailed Serial-Interface Timing Sequence
V
DD
6kΩ
DOUT
6kΩ
GND
DOUT
C
L
C
L
GND
a) HIGH -Z TO V
OH
, V
OL
TO V
OH
, AND V
OH
TO HIGH -Z
b) HIGH -Z TO V
OL
, V
OH
TO V
OL
, AND V
OL
TO HIGH -Z
Figure 2. Load Circuits for Enable/Disable Times
4
_______________________________________________________________________________________
150ksps, 12-Bit, 2-Channel Single-Ended, and
1-Channel True-Differential ADCs
Typical Operating Characteristics
(V
DD
= +3V, V
REF
= +2.5V for MAX1287/MAX1289. V
DD
= +5V, V
REF
= +4.096V for MAX1286/MAX1288; 0.1µF capacitor at REF,
f
SCLK
= 8MHz (50% duty cycle); AIN- = GND for MAX1288/MAX1289, T
A
= +25°C, unless otherwise noted.)
INTEGRAL NONLINEARITY
vs. OUTPUT CODE
MAX1286-9 toc01
MAX1286–MAX1289
INTEGRAL NONLINEARITY
vs. OUTPUT CODE
MAX1286-9 toc02
DIFFERENTIAL NONLINEARITY
vs. OUTPUT CODE
0.8
0.6
0.4
DNL (LSB)
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
MAX1287/MAX1289
MAX1286-9 toc03
1.0
0.8
0.6
0.4
INL (LSB)
MAX1287/MAX1289
1.0
0.8
0.6
0.4
INL (LSB)
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
MAX1286/MAX1288
1.0
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
0
500 1000 1500 2000 2500 3000 3500 4000 4500
OUTPUT CODE
0
500 1000 1500 2000 2500 3000 3500 4000 4500
OUTPUT CODE
0
500 1000 1500 2000 2500 3000 3500 4000 4500
OUTPUT CODE
DIFFERENTIAL NONLINEARITY
vs. OUTPUT CODE
MAX1286-9 toc04
SUPPLY CURRENT
vs. SAMPLING RATE
MAX1286-9 toc05
SUPPLY CURRENT
vs. SAMPLING RATE
MAX1286/MAX1288
MAX1286-9 toc06
1.0
0.8
0.6
0.4
DNL (LSB)
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
0
MAX1286/MAX1288
1000
MAX1287/MAX1289
1000
SUPPLY CURRENT (µA)
SUPPLY CURRENT (µA)
100
100
10
10
1
1
0
500 1000 1500 2000 2500 3000 3500 4000 4500
OUTPUT CODE
0
0.1
1
10
100
1000
SAMPLING RATE (ksps)
0.1
0
0.1
1
10
100
1000
SAMPLING RATE (ksps)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX1286-9 toc07
SHUTDOWN CURRENT
vs. SUPPLY VOLTAGE
MAX1286-9 toc08
SUPPLY CURRENT
vs. TEMPERATURE
MAX1286
380
SUPPLY CURRENT (µA)
MAX1286-9 toc09
380
360
340
SUPPLY CURRENT (µA)
320
300
280
260
240
220
200
180
2.7
3.2
3.7
4.2
V
DD
(V)
4.7
5.2
300
250
SHUTDOWN CURRENT (nA)
200
150
100
50
0
2.7
3.2
3.7
4.2
V
DD
(V)
4.7
5.2
430
330
280
230
180
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
_______________________________________________________________________________________
5