General Description
The MAX1286MAX1289 are low-cost, micropower, seri-
al output 12-bit analog-to-digital converters (ADCs)
available in a tiny 8-pin SOT23. The MAX1286/MAX1288
operate with a single +5V supply. The MAX1287/
MAX1289 operate with a single +3V supply. The
devices feature a successive-approximation ADC, auto-
matic 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. AutoShutdownTM (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
SPITM/QSPITM/MICROWIRETMcompatible 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.
Applications
Low-Power Data Acquisition
Portable Temperature Monitors
Flowmeters
Touch Screens
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/MICROWIRECompatible Interface for
DSPs and Processors
o
Internal Conversion Clock
o
8-Pin SOT23 Package
MAX1286MAX1289
150ksps, 12-Bit, 2-Channel Single-Ended, and
1-Channel True-Differential ADCs in SOT23
________________________________________________________________ Maxim Integrated Products
1
CNVST
REF
GND
1
2
8
7
SCLK
DOUT
AIN1 (AIN+)
AIN2 (AIN-)
V
DD
SOT23
TOP VIEW
( ) ARE FOR THE MAX1288/MAX1289
3
4
6
5
MAX1286
MAX1287
MAX1288
MAX1289
Pin Configuration
19-2231; Rev 0; 10/01
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
Ordering Information
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.
PART
TEMP.
RANGE
PIN-
PACKAGE
TOP
MARK
MAX1286
EKA-T
-40°C to +85°C
8 SOT23-8
AAFA
MAX1287
EKA-T
-40°C to +85°C
8 SOT23-8
AAEW
MAX1288
EKA-T
-40°C to +85°C
8 SOT23-8
AAFC
MAX1289
EKA-T
-40°C to +85°C
8 SOT23-8
AAEY
EVALUATION KIT
AVAILABLE
MAX1286MAX1289
150ksps, 12-Bit, 2-Channel Single-Ended, and
1-Channel True-Differential ADCs in SOT23
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
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.)
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.
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
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-60°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DC ACCURACY
(Note 1)
Resolution
12
Bits
Relative Accuracy (Note 2)
INL
±
1.0
LSB
Differential Nonlinearity
DNL
No missing codes over temperature
±
1.0
LSB
Offset Error
±
2
±
4
LSB
Gain Error (Note 3)
±
2
±
4
LSB
Gain Temperature Coefficient
±
0.4
ppm/
°
C
Offset Tem p er atur e C oeffi ci ent
±
0.4
p p m/
°
C
Channel-to-Channel Offset Matching
±
0.1
LSB
Channel-to-Channel Gain Matching
±
0.1
LSB
Input Common-Mode Rejection
CMR
V
CM
= 0V to V
DD
; zero scale input
±
0.1
mV
DYNAMIC SPECIFICATIONS:
(f
IN
(sine-wave) = 10kHz, V
IN
= 4.096Vp-p for MAX1086/MAX1088 or V
IN
= 2.5V
p-p
for MAX1087/MAX1089, 150ksps, f
SCLK
= 8MHz, (50% duty cycle) AIN- = GND for MAX1088/MAX1089)
Signal to Noise Plus Distortion
SINAD
70
dB
Total Harmonic Distortion
(up to the 5
th
harmonic)
THD
-80
dB
Spurious-Free Dynamic Range
SFDR
80
dB
Full-Power Bandwidth
-3dB point
1
MHz
Full-Linear Bandwidth
SINAD > 56dB
100
kHz
CONVERSION RATE
Conversion Time
t
CONV
Does not include t
ACQ
3.7
µs
T/H Acquisition Time
t
ACQ
1.4
µs
Aperture Delay
30
ns
Aperture Jitter
<50
ps
Maximum Serial Clock Frequency
f
SCLK
8
MHz
Duty Cycle
30
70
%
ANALOG INPUT
Unipolar
0
V
REF
Input Voltage Range (Note 4)
Bipolar
-V
REF
/2
V
REF
/2
V
MAX1286MAX1289
150ksps, 12-Bit, 2-Channel Single-Ended, and
1-Channel True-Differential ADCs in SOT23
_______________________________________________________________________________________
3
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
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Input Leakage Current
C hannel not sel ected or conver si on stop p ed
±
0.01
±
1
µA
Input Capacitance
34
pF
EXTERNAL REFERENCE INPUT
Input Voltage Range
V
REF
1.0
V
DD
+50mV
V
V
REF
= +2.5V at 150ksps
16
30
V
REF
= +4.096V at 150ksps
26
45
Input Current
I
REF
Acquisition/Between conversions
±
0.01
±
1
µA
DIGITAL INPUTS/OUTPUTS (SCLK, CNVST, DOUT)
Input Low Voltage
V
IL
0.8
V
Input High Voltage
V
IH
V
DD
-1
V
Input Leakage Current
I
L
±0.01
±
1.0
µA
Input Capacitance
C
IN
15
pF
I
SINK
= 2mA
0.4
V
Output Low Voltage
V
OL
I
SINK
= 4mA
0.8
V
Output High Voltage
V
OH
I
SOURCE
= 1.5mA
V
DD
-0.5
V
Three-State Leakage Current
CNVST = GND
±0.05
±
10
µA
Three-State Output Capacitance
C
OUT
CNVST = GND
15
pF
POWER REQUIREMENTS
MAX1086/MAX1088
4.75
5.0
5.25
Positive Supply Voltage
V
DD
MAX1087/MAX1089
2.7
3.0
3.6
V
f
SAMPLE
=150ksps
245
350
f
SAMPLE
=100ksps
150
f
SAMPLE
=10ksps
15
V
DD
= +3V
f
SAMPLE
=1ksps
2
f
SAMPLE
=150ksps
320
400
f
SAMPLE
=100ksps
215
f
SAMPLE
=10ksps
22
V
DD
= +5V
f
SAMPLE
=1ksps
2.5
Positive Supply Current
I
DD
Shutdown
0.2
5
µA
V
DD
= 5V
±
5%; full-scale input
±
0.3
±1.0
Positive Supply Rejection
PSR
V
DD
= +2.7V to +3.6V; full-scale input
±
0.4
±1.2
mV
MAX1286MAX1289
150ksps, 12-Bit, 2-Channel Single-Ended, and
1-Channel True-Differential ADCs in SOT23
4
_______________________________________________________________________________________
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
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
SCLK Pulse Width High
t
CH
38
ns
SCLK Pulse Width Low
t
CL
38
ns
SCLK Fall to DOUT Transition
t
DOT
C
LOAD
= 30pF
60
ns
SCLK Rise to DOUT Disable
t
DOD
C
LOAD
= 30pF
100
500
ns
CNVST Rise to DOUT Enable
t
DOE
C
LOAD
= 30pF
80
ns
CNVST Fall to MSB Valid
t
CONV
C
LOAD
= 30pF
3.7
µs
CNVST Pulse Width
t
CSW
30
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
SCLK
DOUT
t
DOE
HIGH-Z
HIGH-Z
t
CSW
t
CL
t
CH
t
DOD
t
DOT
DOUT
6k
6k
C
L
GND
DOUT
C
L
GND
V
DD
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 1. Detailed Serial-Interface Timing Sequence
Figure 2. Load Circuits for Enable/Disable Times
MAX1286MAX1289
150ksps, 12-Bit, 2-Channel Single-Ended, and
1-Channel True-Differential ADCs in SOT23
_______________________________________________________________________________________
5
-1.0
-0.6
-0.8
-0.2
-0.4
0.2
0
0.4
0.8
0.6
1.0
0
1000 1500 2000
500
2500 3000 3500 4000 4500
INTEGRAL NONLINEARITY
vs. OUTPUT CODE
MAX1286-9 toc01
OUTPUT CODE
INL (LSB)
MAX1287/MAX1289
-1.0
-0.6
-0.8
-0.2
-0.4
0.2
0
0.4
0.8
0.6
1.0
0
1000 1500 2000
500
2500 3000 3500 4000 4500
INTEGRAL NONLINEARITY
vs. OUTPUT CODE
MAX1286-9 toc02
OUTPUT CODE
INL (LSB)
MAX1286/MAX1288
-1.0
-0.6
-0.8
-0.2
-0.4
0.2
0
0.4
0.8
0.6
1.0
0
1000 1500 2000
500
2500 3000 3500 4000 4500
DIFFERENTIAL NONLINEARITY
vs. OUTPUT CODE
MAX1286-9 toc03
OUTPUT CODE
DNL (LSB)
MAX1287/MAX1289
-1.0
-0.6
-0.8
-0.2
-0.4
0.2
0
0.4
0.8
0.6
1.0
0
1000 1500 2000
500
2500 3000 3500 4000 4500
DIFFERENTIAL NONLINEARITY
vs. OUTPUT CODE
MAX1286-9 toc04
OUTPUT CODE
DNL (LSB)
MAX1286/MAX1288
1000
1
0
10
100
1000
SUPPLY CURRENT
vs. SAMPLING RATE
10
100
MAX1286-9 toc05
SAMPLING RATE (ksps)
SUPPLY CURRENT (
µ
A)
0.1
0
1
MAX1287/MAX1289
1000
1
SUPPLY CURRENT
vs. SAMPLING RATE
10
100
MAX1286-9 toc06
SAMPLING RATE (ksps)
SUPPLY CURRENT (
µ
A)
0.1
0
10
100
1000
0.1
1
MAX1286/MAX1288
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.)
0
50
100
200
250
150
300
2.7
3.7
4.2
3.2
4.7
5.2
SHUTDOWN CURRENT
vs. SUPPLY VOLTAGE
MAX1286-9 toc08
V
DD
(V)
SHUTDOWN CURRENT (nA)
180
220
200
260
240
300
320
340
360
280
380
2.7
3.7
4.2
3.2
4.7
5.2
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX1286-9 toc07
V
DD
(V)
SUPPLY CURRENT (
µ
A)
180
230
380
330
280
430
-40
0
20
-20
40
60
80
SUPPLY CURRENT
vs. TEMPERATURE
MAX1286-9 toc09
TEMPERATURE (
°
C)
SUPPLY CURRENT (
µ
A)
MAX1286
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